;Clowns (Midway, 1978) - annotated disassembly of the program ROM $0000-$17FF. ;MAME set 'clowns' (rev. 2): h2.cpu g2.cpu f2.cpu e2.cpu d2.cpu c2.cpu, 1K each. ;Intel 8080 on the Midway 8080 black & white board: 256 x 224 bitmap at $2400, ;MB14241 shifter on ports 1-3, tone generator and discrete sounds on ports 5-7. ;No source for this game is known; every name, routine header and comment was ;written for this disassembly from reading the code. The hardware notes follow ;the MAME driver (mw8080bw.cpp). ;Every line below was re-encoded and byte-compared with the ROM (verify.py). ;Syntax: Intel 8080 mnemonics; directives as the Tempest / Space Duel listings ;(.org, .include, .alias, .byte, .word); $ is hex, < and > take the low and ;high byte, [ ] groups an expression. Every code and data line starts with its ;address label Lxxxx; named labels sit on their own line above it. .org $0000 .include "clowns_defines.asm" ;============================================================================== ; SECTION 1 Reset and interrupt entries, self test ($0000-$0137) ; The reset and the two RST interrupt entries, then the RAM and ROM tests that ; run instead of the game while the self-test switch (INP_DIP b7) is on. ;============================================================================== ;------------------------------------------------------------------------------ ; Reset - Power-on / watchdog reset entry. ;------------------------------------------------------------------------------ Reset: L0000: NOP L0001: NOP L0002: LXI SP,$2400 ;Stack at the top of work RAM L0005: JMP Boot ;Self-test switch decides: game or RAM/ROM test ;------------------------------------------------------------------------------ ; Rst1 - RST 1: mid-screen interrupt (vector $CF). ; Saves all registers; Rst1Handler leaves through IrqExit. ;------------------------------------------------------------------------------ Rst1: L0008: PUSH PSW L0009: PUSH B L000A: PUSH D L000B: PUSH H L000C: JMP Rst1Handler ;Mid-screen work L000F: .byte $00 ;unused ;------------------------------------------------------------------------------ ; Rst2 - RST 2: vertical blank interrupt (vector $D7). ;------------------------------------------------------------------------------ Rst2: L0010: PUSH PSW L0011: PUSH B L0012: PUSH D L0013: PUSH H L0014: JMP Rst2Handler ;Vblank work L0017: .byte $00 ;unused ;------------------------------------------------------------------------------ ; Boot - Choose between the self test and the game. ;------------------------------------------------------------------------------ Boot: L0018: IN INP_DIP ;DIP b7 = self-test switch L001A: ANI $80 L001C: JNZ RamTest ;On: run the RAM and ROM tests L001F: JMP GameStart ;Off: start the game ;------------------------------------------------------------------------------ ; RamTest - Walking-bit test of all RAM $2000-$3FFF. ; B = test bit, rotated through all 8 positions. Each pass: write B everywhere; ; walk back down checking B and replacing it with its complement; walk up ; again checking the complement and clearing. Wrong bits are OR-ed into D for ; even addresses and E for odd ones. The stack is not used: RAM is not ; trusted yet. ; The coin switch held down at any point leaves for the switch test. ;------------------------------------------------------------------------------ RamTest: L0022: MVI B,$01 ;First bit to walk L0024: LXI D,$0000 ;DE = bad bits found so far (D even addresses, E odd) L0027: LXI H,WorkRam ;Start of RAM ;Pass 1, upward: write the pattern and read it straight back L002A: OUT OUT_WATCHDOG ;Keep the watchdog quiet L002C: IN INP_SWITCH ;Coin switch down (active low)? L002E: ANI $40 L0030: JZ SwitchTest ;Yes: go to the switch test L0033: MOV M,B ;Write the pattern L0034: MOV A,M L0035: XRA B ;A = bits that read back wrong L0036: JZ L0048 ;None L0039: MOV C,A ;C = wrong bits L003A: MOV A,L L003B: ANI $01 ;Even or odd address? L003D: MOV A,C L003E: JNZ L0046 ;Odd: record in E L0041: ORA D ;Even: record in D L0042: MOV D,A L0043: JMP L0048 L0046: ORA E ;Odd: record in E L0047: MOV E,A L0048: INX H ;Next address L0049: MOV A,H L004A: CPI $40 ;Until $4000 L004C: JNZ L002A ;Pass 2, downward: check the pattern, replace it with its complement L004F: OUT OUT_WATCHDOG L0051: IN INP_SWITCH L0053: ANI $40 L0055: JZ SwitchTest ;Coin switch: to the switch test L0058: DCX H ;Next address down L0059: MOV A,H L005A: CPI $1F ;Below $2000? L005C: JZ L008C ;Yes: pass 3 L005F: MOV A,M ;Pattern still there? L0060: XRA B L0061: JZ L0073 L0064: MOV C,A L0065: MOV A,L L0066: ANI $01 L0068: MOV A,C L0069: JNZ L0071 L006C: ORA D L006D: MOV D,A L006E: JMP L0073 L0071: ORA E L0072: MOV E,A L0073: MOV A,B ;Write the complement L0074: CMA L0075: MOV M,A L0076: XRA M ;A = bits that did not take L0077: JZ L004F ;None: next address L007A: MOV C,A L007B: MOV A,L L007C: ANI $01 L007E: MOV A,C L007F: JNZ L0087 L0082: ORA D L0083: MOV D,A L0084: JMP L0089 L0087: ORA E L0088: MOV E,A L0089: JMP L004F ;Next address ;Pass 3, upward: check the complement, leave RAM cleared L008C: OUT OUT_WATCHDOG L008E: IN INP_SWITCH L0090: ANI $40 L0092: JZ SwitchTest ;Coin switch: to the switch test L0095: INX H L0096: MOV A,H L0097: CPI $40 ;Until $4000 L0099: JZ L00B6 ;Done: next bit L009C: MOV A,B ;Complement still there? L009D: CMA L009E: XRA M L009F: JZ L00B1 L00A2: MOV C,A L00A3: MOV A,L L00A4: ANI $01 L00A6: MOV A,C L00A7: JNZ L00AF L00AA: ORA D L00AB: MOV D,A L00AC: JMP L00B1 L00AF: ORA E L00B0: MOV E,A L00B1: XRA A ;Leave the byte zero L00B2: MOV M,A L00B3: JMP L008C L00B6: MOV A,B ;Next bit position L00B7: RLC L00B8: MOV B,A L00B9: JNC L0027 ;Until the bit falls out of the byte L00BC: MOV A,D ;Any bad bit in either half? L00BD: ORA E L00BE: JZ RomTest ;No: RAM is good, test the ROMs ;------------------------------------------------------------------------------ ; RamError - Show the bad RAM bits as 16 columns over the whole screen. ; DE (the bad-bit word, D15 at the left) is kept in SP. Each bit takes two ; bytes of every 32-byte line: a solid 8-pixel block if the bit is good, blank ; if it is bad, then a 2-pixel separator. The pattern is written from $2000 up, ; so work RAM is overwritten as well. Ends in the self-test wait loop. ;------------------------------------------------------------------------------ RamError: L00C1: XCHG ;HL = bad-bit word L00C2: SPHL ;Keep it in SP (no RAM needed) L00C3: LXI D,WorkRam ;Fill from the start of RAM L00C6: MVI B,$00 ;256 groups of 32 bytes = all of RAM L00C8: LXI H,$0000 ;HL = the bad-bit word again L00CB: DAD SP L00CC: MVI C,$10 ;16 bits per line L00CE: XRA A L00CF: DAD H ;Next bit into carry L00D0: JC L00D4 ;Bad bit: leave the block blank L00D3: CMA ;Good bit: solid block L00D4: STAX D L00D5: INX D L00D6: MVI A,$18 ;Separator column L00D8: STAX D L00D9: INX D L00DA: DCR C L00DB: JNZ L00CE ;16 bits L00DE: DCR B L00DF: JNZ L00C8 ;All lines L00E2: JMP SelfTestWait ;Wait for the self-test switch to go off ;------------------------------------------------------------------------------ ; RomTest - Checksum the six ROMs. ; For each 1K ROM: check byte from RomCheckTable + sum of the 1024 bytes + 1 ; must be 0. For a ROM that fails, its letter (H G F E D C) is printed on line ; 144, starting at column 12. If nothing was printed the whole self test starts ; over (through Reset), so it repeats for as long as the switch is on. ;------------------------------------------------------------------------------ RomTest: L00E5: LXI SP,$2400 ;RAM is good: the stack can be used L00E8: LXI H,$360C ;Screen position for the first bad-ROM letter L00EB: PUSH H L00EC: LXI H,$0000 ;HL = ROM address L00EF: LXI D,RomCheckTable ;DE = check byte / letter table L00F2: LXI B,$0400 ;1024 bytes per ROM L00F5: LDAX D ;Start the sum with the ROM's check byte L00F6: INX D L00F7: ADD M ;Add a ROM byte L00F8: OUT OUT_WATCHDOG L00FA: INX H L00FB: DCR C L00FC: JNZ L00F7 ;256 bytes L00FF: DCR B L0100: JNZ L00F7 ;4 x 256 L0103: INR A ;Sum + 1 = 0? L0104: JZ L0111 ;Yes: ROM good, skip its letter L0107: XTHL ;HL = screen position, ROM address to the stack L0108: XCHG ;DE = screen position, HL = the ROM's letter L0109: MVI A,$01 ;One character L010B: CALL DrawString ;Print the letter; DE moves to the next column L010E: XCHG ;Back: DE = table, HL = screen position L010F: XTHL ;Screen position to the stack, HL = ROM address L0110: DCX D ;(cancels the INX below: DrawString already stepped past the letter) L0111: INX D ;Skip the letter L0112: MOV A,H ;End of the last ROM ($1800)? L0113: CPI $18 L0115: JNZ L00F2 ;No: next ROM L0118: POP H ;Screen position L0119: MOV A,L L011A: CPI $0C ;Still column 12: nothing was printed? L011C: JZ Reset ;All ROMs good: run the self test again ;------------------------------------------------------------------------------ ; SelfTestWait - Hold the error display until the self-test switch goes off. ;------------------------------------------------------------------------------ SelfTestWait: L011F: OUT OUT_WATCHDOG L0121: IN INP_DIP ;Self-test switch L0123: ANI $80 L0125: JZ Reset ;Off: reset (which starts the game) L0128: JMP SelfTestWait ;Still on: keep waiting RomCheckTable: L012B: .byte $00, $48 ;ROM H $0000-$03FF: check byte, letter shown if the sum is wrong L012D: .byte $63, $47 ;ROM G $0400-$07FF: check byte, letter shown if the sum is wrong L012F: .byte $B8, $46 ;ROM F $0800-$0BFF: check byte, letter shown if the sum is wrong L0131: .byte $7B, $45 ;ROM E $0C00-$0FFF: check byte, letter shown if the sum is wrong L0133: .byte $0E, $44 ;ROM D $1000-$13FF: check byte, letter shown if the sum is wrong L0135: .byte $17, $43 ;ROM C $1400-$17FF: check byte, letter shown if the sum is wrong L0137: .byte $02 ;not read by the test; presumably the byte adjusted to make ROM H add up ;============================================================================== ; SECTION 2 Interrupt work ($0138-$0475) ; Everything that touches the screen runs in the two interrupts. Each frame ; one of them moves and redraws the flying clown and the other does the frame ; task (seesaw and rider on even frames; balloons, timers and the coin switch ; on odd frames). Which does which depends on where the flyer is, so that it ; is never redrawn while the beam is passing over it. ;============================================================================== ;------------------------------------------------------------------------------ ; Rst1Handler - Mid-screen interrupt. ; Flyer above Y $50 (already displayed): update the flyer now and leave the ; frame task to the vblank interrupt. Otherwise do the frame task now. ;------------------------------------------------------------------------------ Rst1Handler: L0138: LHLD FLYER_PTR ;The clown in the air L013B: LXI B,CL_Y L013E: DAD B L013F: MOV A,M ;Its Y L0140: SUI $50 ;Above line $50? L0142: JC L0146 ;Yes: A is non-zero L0145: XRA A ;No: A = 0 L0146: STA FLYER_HIGH L0149: JZ FrameTask ;Flyer is low: this interrupt does the frame task ;------------------------------------------------------------------------------ ; UpdateFlyer - Erase, move and redraw the flying clown, test for contact; then the tune. ; Skipped while FREEZE is set or while a contact is waiting for HandleContact. ;------------------------------------------------------------------------------ UpdateFlyer: L014C: LDA FREEZE ;Frozen for a bonus message? L014F: ANA A L0150: JNZ L016F ;Yes: tune only L0153: LDA CONTACT_ROW ;Contact not handled yet? L0156: ANA A L0157: JNZ L016F ;Yes: tune only L015A: LHLD FLYER_PTR L015D: CALL EraseFlyer ;Remove the old picture L0160: LHLD FLYER_PTR L0163: CALL DrawFlyer ;Move and draw; saves the background it covers L0166: LDA FREEZE_REQ ;A freeze request takes effect after this last draw L0169: STA FREEZE L016C: CALL CheckContact ;Did the picture land on anything? L016F: CALL PlayTune ;Music, once a frame L0172: JMP IrqExit ;------------------------------------------------------------------------------ ; Rst2Handler - Vertical blank interrupt. ; Reads the paddle, refreshes OUT_MISC (paddle select follows PLAYER), then ; does whichever half of the frame Rst1Handler left. ;------------------------------------------------------------------------------ Rst2Handler: L0175: LDA PADDLE_ENABLE ;Paddle wanted (game or switch test)? L0178: ANA A L0179: JZ L0181 L017C: IN INP_PADDLE ;Paddle of the selected player L017E: STA PADDLE_POS L0181: LXI H,OUT3_SHADOW L0184: MOV A,M L0185: ANI $FD ;Drop the old paddle select L0187: MOV B,A L0188: LDA PLAYER ;PLAYER is $00 or $FF L018B: ANI $02 ;b1 = paddle select L018D: ORA B L018E: MOV M,A L018F: OUT OUT_MISC ;Coin counter and paddle select L0191: LDA FLYER_HIGH ;Did the mid-screen interrupt update the flyer? L0194: ANA A L0195: JZ UpdateFlyer ;No: update it now ;------------------------------------------------------------------------------ ; FrameTask - Once a frame: seesaw and rider (even frames) or balloons and timers (odd frames). ;------------------------------------------------------------------------------ FrameTask: L0198: LXI H,FRAME_CTR L019B: INR M L019C: MOV A,M L019D: RAR L019E: JC L01B6 ;Odd frame L01A1: LHLD RIDER_PTR ;The clown on the seesaw L01A4: CALL EraseRider ;Blank its old picture if asked (it has just landed) L01A7: CALL EraseSeesaw ;Erase the seesaw, take the new X L01AA: CALL DrawSeesaw ;Draw the seesaw L01AD: LHLD RIDER_PTR L01B0: CALL DrawRider ;Draw the rider on its low end L01B3: JMP IrqExit ;Odd frame: one of the six balloon passes, then the timers L01B6: LXI H,FrameTimers ;Everything below returns to FrameTimers L01B9: PUSH H L01BA: LDA FREEZE ;Frozen: balloons stand still L01BD: ANA A L01BE: RNZ L01BF: LXI H,BALLOON_PHASE ;Next of the six passes L01C2: MOV A,M L01C3: INR A L01C4: CPI $06 L01C6: JC L01CA L01C9: XRA A L01CA: MOV M,A L01CB: MOV C,A L01CC: MVI B,$00 L01CE: LXI H,BalloonTasks ;4 bytes per entry L01D1: DAD B L01D2: DAD B L01D3: DAD B L01D4: DAD B L01D5: MOV E,M ;DE = first balloon of the pass L01D6: INX H L01D7: MOV D,M L01D8: INX H L01D9: MOV A,M ;HL = routine L01DA: INX H L01DB: MOV H,M L01DC: MOV L,A L01DD: PCHL ;MoveBalloonsRight / MoveBalloonsLeft with DE ;------------------------------------------------------------------------------ ; FrameTimers - Odd-frame tail: timers and coin switch. ;------------------------------------------------------------------------------ FrameTimers: L01DE: CALL TickSecondTimer L01E1: CALL TickTimers L01E4: CALL CoinSwitch ;------------------------------------------------------------------------------ ; IrqExit - Restore the registers and return from the interrupt. ;------------------------------------------------------------------------------ IrqExit: L01E7: POP H L01E8: POP D L01E9: POP B L01EA: POP PSW L01EB: EI L01EC: RET ;------------------------------------------------------------------------------ ; TickSecondTimer - Count TMR_TIMEOUT down once every 30 odd frames (about a second). ; Nothing happens while the previous expiry is still waiting in EVT_TIMEOUT. ;------------------------------------------------------------------------------ TickSecondTimer: L01ED: LXI D,EVT_TIMEOUT L01F0: LDAX D ;Last event not taken yet? L01F1: ANA A L01F2: RNZ L01F3: MOV B,A ;B = 0: expiry bits L01F4: LXI H,SECOND_PRESCALE L01F7: DCR M ;One second gone? L01F8: RNZ L01F9: MVI M,$1E ;Reload: 30 odd frames L01FB: MVI C,$01 ;One timer L01FD: LXI H,TMR_TIMEOUT L0200: CALL TickTimerList L0203: STAX D ;EVT_TIMEOUT b0 = expired L0204: RET ;------------------------------------------------------------------------------ ; TickTimers - Count the 30 Hz timers down and post the ones that reach zero. ; Eight timers at TMR_SCRIPT -> EVT_TIMERS, three at TMR_COIN_CTR -> ; EVT_TIMERS2. Each group is skipped while its event byte is still non-zero. ;------------------------------------------------------------------------------ TickTimers: L0205: LXI H,TMR_SCRIPT L0208: LXI D,EVT_TIMERS L020B: LDAX D ;Events not taken yet? L020C: ANA A L020D: RNZ L020E: MOV B,A L020F: MVI C,$08 ;Eight timers L0211: CALL TickTimerList L0214: STAX D ;b7 = TMR_SCRIPT ... b0 = TMR_REFILL L0215: LXI D,EVT_TIMERS2 L0218: LDAX D ;Events not taken yet? L0219: ANA A L021A: RNZ L021B: MOV B,A L021C: MVI C,$03 ;Three timers follow the eight L021E: CALL TickTimerList L0221: STAX D ;b2 = TMR_COIN_CTR, b1 = TMR_TUMBLE, b0 = TMR_FREEZE L0222: RET ;------------------------------------------------------------------------------ ; TickTimerList - Decrement C timers at HL; shift a 1 into B for each that reaches zero. ; A timer that is already 0 stays 0 and posts nothing. Returns A = B. ;------------------------------------------------------------------------------ TickTimerList: L0223: MOV A,M L0224: ANA A L0225: JZ L022D ;Stopped L0228: DCR M ;Count down L0229: JNZ L022D ;Still running L022C: STC ;Just expired L022D: MOV A,B ;Shift the result bit into B L022E: RAL L022F: MOV B,A L0230: INX H L0231: DCR C L0232: JNZ TickTimerList ;Next timer L0235: RET L0236: .byte $00 ;unused ;------------------------------------------------------------------------------ ; PlayTune - Step the tune player, once a frame. ; A tune is: tempo byte ($80 + frames per beat), then (beats, note) pairs, ; then 0. The note is an index into NoteTable; with b7 set it runs straight ; into the next note, otherwise one frame of silence follows it. A tempo byte ; also turns the sound board on. ;------------------------------------------------------------------------------ PlayTune: L0237: LDA TUNE_ON ;Tune playing? L023A: ANA A L023B: RZ L023C: LXI H,TUNE_TICKS ;Frames left in this beat L023F: MOV A,M L0240: ANA A L0241: JZ L0246 ;Beat over L0244: DCR M L0245: RET L0246: INX H ;Beats left in this note L0247: MOV A,M L0248: ANA A L0249: JZ L0253 ;Note over L024C: DCR M L024D: DCX H ;Start the next beat L024E: LDA TUNE_TEMPO L0251: MOV M,A L0252: RET L0253: INX H ;A gap owed after the note? L0254: MOV A,M L0255: ANA A L0256: JZ L025E ;No: next note L0259: DCR M L025A: XRA A ;Yes: one frame of silence L025B: OUT OUT_TONE_LO L025D: RET L025E: LHLD TUNE_PTR ;Next tune byte L0261: MOV A,M L0262: ANA A L0263: JNZ L0271 ;Not the end L0266: XRA A ;End of tune: tone off L0267: OUT OUT_TONE_LO L0269: LDA GAME_ACTIVE ;In a game the other sounds stay enabled L026C: ANA A L026D: RNZ L026E: OUT OUT_SOUND ;Attract mode: sound board off L0270: RET L0271: JP L027F ;Plain beat count L0274: ANI $7F ;Tempo byte: frames per beat L0276: STA TUNE_TEMPO L0279: MVI A,$08 ;Sound enable L027B: OUT OUT_SOUND L027D: INX H ;The beat count follows L027E: MOV A,M L027F: STA TUNE_BEATS ;Beats for this note L0282: INX H L0283: LDA TUNE_TEMPO ;B = frames for the first beat L0286: MOV B,A L0287: MOV A,M ;The note L0288: ANA A L0289: JM L0292 ;b7: no gap L028C: MVI A,$01 ;One frame of silence after the note, L028E: STA TUNE_GAP L0291: DCR B ;taken out of its first beat L0292: MOV A,B L0293: STA TUNE_TICKS L0296: MOV A,M L0297: INX H L0298: SHLD TUNE_PTR ;Tune pointer past the note L029B: ANI $7F ;Note number L029D: MOV C,A ;Program the tone generator with note C L029E: MVI B,$00 L02A0: LXI H,NoteTable L02A3: DAD B L02A4: DAD B ;Two bytes per note L02A5: MOV A,M L02A6: OUT OUT_TONE_LO ;Enable bit and low period bits L02A8: INX H L02A9: MOV A,M L02AA: OUT OUT_TONE_HI ;High period bits L02AC: RET L02AD: .byte $00 ;unused ;------------------------------------------------------------------------------ ; NoteTable - Tone generator settings for notes $00-$25. ; Byte 0 goes to OUT_TONE_LO (b0 enable, b1-b5 low bits), byte 1 to ; OUT_TONE_HI (high 6 bits). The 12-bit counter preset is 64 x high + 2 x low; ; the counter runs from it up to 4096 at 998.4 kHz and toggles the output, so ; the tone is 998400 / (4096 - preset) / 2 Hz (per MAME's model of the board): ; three octaves of semitones. ;------------------------------------------------------------------------------ NoteTable: L02AE: .byte $00, $00 ;note $00: rest (tone off) L02B0: .byte $3F, $13 ;note $01: preset 1278, 177 Hz L02B2: .byte $1D, $16 ;note $02: preset 1436, 188 Hz L02B4: .byte $33, $18 ;note $03: preset 1586, 199 Hz L02B6: .byte $3F, $1A ;note $04: preset 1726, 211 Hz L02B8: .byte $05, $1D ;note $05: preset 1860, 223 Hz L02BA: .byte $01, $1F ;note $06: preset 1984, 236 Hz L02BC: .byte $39, $20 ;note $07: preset 2104, 251 Hz L02BE: .byte $27, $22 ;note $08: preset 2214, 265 Hz L02C0: .byte $11, $24 ;note $09: preset 2320, 281 Hz L02C2: .byte $35, $25 ;note $0A: preset 2420, 298 Hz L02C4: .byte $13, $27 ;note $0B: preset 2514, 316 Hz L02C6: .byte $2B, $28 ;note $0C: preset 2602, 334 Hz L02C8: .byte $3F, $29 ;note $0D: preset 2686, 354 Hz L02CA: .byte $0F, $2B ;note $0E: preset 2766, 375 Hz L02CC: .byte $19, $2C ;note $0F: preset 2840, 397 Hz L02CE: .byte $1F, $2D ;note $10: preset 2910, 421 Hz L02D0: .byte $21, $2E ;note $11: preset 2976, 446 Hz L02D2: .byte $21, $2F ;note $12: preset 3040, 473 Hz L02D4: .byte $1D, $30 ;note $13: preset 3100, 501 Hz L02D6: .byte $15, $31 ;note $14: preset 3156, 531 Hz L02D8: .byte $09, $32 ;note $15: preset 3208, 562 Hz L02DA: .byte $3B, $32 ;note $16: preset 3258, 596 Hz L02DC: .byte $29, $33 ;note $17: preset 3304, 630 Hz L02DE: .byte $17, $34 ;note $18: preset 3350, 669 Hz L02E0: .byte $3F, $34 ;note $19: preset 3390, 707 Hz L02E2: .byte $27, $35 ;note $1A: preset 3430, 750 Hz L02E4: .byte $0D, $36 ;note $1B: preset 3468, 795 Hz L02E6: .byte $31, $36 ;note $1C: preset 3504, 843 Hz L02E8: .byte $11, $37 ;note $1D: preset 3536, 891 Hz L02EA: .byte $31, $37 ;note $1E: preset 3568, 945 Hz L02EC: .byte $0F, $38 ;note $1F: preset 3598, 1002 Hz L02EE: .byte $2B, $38 ;note $20: preset 3626, 1062 Hz L02F0: .byte $05, $39 ;note $21: preset 3652, 1124 Hz L02F2: .byte $1D, $39 ;note $22: preset 3676, 1189 Hz L02F4: .byte $35, $39 ;note $23: preset 3700, 1261 Hz L02F6: .byte $0B, $3A ;note $24: preset 3722, 1335 Hz L02F8: .byte $21, $3A ;note $25: preset 3744, 1418 Hz L02FA: .byte $00 ;unused ;------------------------------------------------------------------------------ ; DrawSeesaw - Animate and draw the seesaw. ; While it is tipping (b6) the picture number steps 0..4 or 4..0; at the end ; b6 is cleared and b5 (which end is down) flips. The picture is 40 pixels ; wide, drawn bottom row first from line 211 upward through the shifter. ;------------------------------------------------------------------------------ DrawSeesaw: L02FB: LXI H,SEESAW_STATE L02FE: MOV A,M ;On screen? L02FF: ANA A L0300: RP L0301: MOV A,M L0302: ANI $40 ;Tipping? L0304: JZ L0326 ;No: just draw L0307: MOV A,M L0308: ANI $20 ;Which way? L030A: JZ L031F ;Left end is down: run 4 to 0 L030D: INR M ;Right end is down: run 0 to 4 L030E: MOV A,M L030F: ANI $0F L0311: CPI $04 L0313: JC L0326 ;Not there yet L0316: MOV A,M L0317: ANI $BF ;Tipped: stop, L0319: XRI $20 ;and the other end is down now L031B: MOV M,A L031C: JMP L0326 L031F: DCR M L0320: MOV A,M L0321: ANI $0F L0323: JZ L0316 ;Reached 0: stop L0326: MOV A,M L0327: ANI $0F ;Picture number L0329: MOV C,A L032A: MVI B,$00 L032C: INX H L032D: MOV A,M ;X L032E: MOV E,A L032F: ANI $07 ;X within the byte L0331: OUT OUT_SHIFT_AMT ;to the shifter L0333: MOV A,E L0334: RAR ;X / 8 L0335: RAR L0336: RAR L0337: ANI $1F L0339: ORI $60 ;+ $60: L033B: MOV E,A L033C: MVI D,$3E ;DE = $3E60 + X/8: line 211 L033E: LXI H,SeesawPictures ;Picture pointers L0341: DAD B L0342: DAD B L0343: MOV A,M L0344: INX H L0345: MOV H,M L0346: MOV L,A L0347: XCHG ;DE = picture, HL = screen L0348: LDAX D ;B = rows L0349: INX D L034A: MOV B,A L034B: CALL ShiftedByte ;Five bytes of the row L034E: CALL ShiftedByte L0351: CALL ShiftedByte L0354: CALL ShiftedByte L0357: CALL ShiftedByte L035A: XRA A L035B: OUT OUT_SHIFT_DATA ;Flush the shifter into a sixth byte L035D: IN INP_SHIFT L035F: MOV M,A L0360: MOV A,B L0361: LXI B,$FFDB ;One line up (6 bytes written, 5 pointer steps: -37) L0364: DAD B L0365: MOV B,A L0366: DCR B L0367: JNZ L034B ;Next row L036A: RET ;------------------------------------------------------------------------------ ; ShiftedByte - Next picture byte through the shifter to the screen (overwrites). ;------------------------------------------------------------------------------ ShiftedByte: L036B: LDAX D L036C: INX D L036D: OUT OUT_SHIFT_DATA L036F: IN INP_SHIFT L0371: MOV M,A L0372: INX H L0373: RET SeesawPictures: L0374: .word SeesawPic0 ;picture 0 L0376: .word SeesawPic1 ;picture 1 L0378: .word SeesawPic2 ;picture 2 L037A: .word SeesawPic3 ;picture 3 L037C: .word SeesawPic4 ;picture 4 SeesawPic0: L037E: .byte $08 ;8 rows of 5 bytes, bottom row first L037F: .byte $00, $00, $7E, $00, $F8 ;.................######............##### L0384: .byte $00, $00, $3C, $C0, $07 ;..................####........#####..... L0389: .byte $00, $00, $18, $3E, $00 ;...................##....#####.......... L038E: .byte $00, $00, $F0, $01, $00 ;....................#####............... L0393: .byte $00, $80, $0F, $00, $00 ;...............#####.................... L0398: .byte $00, $7C, $00, $00, $00 ;..........#####......................... L039D: .byte $E0, $03, $00, $00, $00 ;.....#####.............................. L03A2: .byte $1F, $00, $00, $00, $00 ;#####................................... SeesawPic1: L03A7: .byte $05 ;5 rows of 5 bytes, bottom row first L03A8: .byte $00, $00, $7E, $00, $F8 ;.................######............##### L03AD: .byte $00, $00, $3C, $C0, $07 ;..................####........#####..... L03B2: .byte $00, $00, $18, $3E, $00 ;...................##....#####.......... L03B7: .byte $00, $00, $F0, $01, $00 ;....................#####............... L03BC: .byte $FF, $FF, $0F, $00, $00 ;####################.................... SeesawPic2: L03C1: .byte $05 ;5 rows of 5 bytes, bottom row first L03C2: .byte $00, $00, $7E, $00, $F8 ;.................######............##### L03C7: .byte $1F, $00, $3C, $C0, $07 ;#####.............####........#####..... L03CC: .byte $E0, $03, $18, $3E, $00 ;.....#####.........##....#####.......... L03D1: .byte $00, $7C, $F0, $01, $00 ;..........#####.....#####............... L03D6: .byte $00, $80, $0F, $00, $00 ;...............#####.................... SeesawPic3: L03DB: .byte $05 ;5 rows of 5 bytes, bottom row first L03DC: .byte $1F, $00, $7E, $00, $00 ;#####............######................. L03E1: .byte $E0, $03, $3C, $00, $00 ;.....#####........####.................. L03E6: .byte $00, $7C, $18, $00, $00 ;..........#####....##................... L03EB: .byte $00, $80, $0F, $FE, $FF ;...............#####.....############### L03F0: .byte $00, $00, $F0, $01, $00 ;....................#####............... SeesawPic4: L03F5: .byte $08 ;8 rows of 5 bytes, bottom row first L03F6: .byte $1F, $00, $7E, $00, $00 ;#####............######................. L03FB: .byte $E0, $03, $3C, $00, $00 ;.....#####........####.................. L0400: .byte $00, $7C, $18, $00, $00 ;..........#####....##................... L0405: .byte $00, $80, $0F, $00, $00 ;...............#####.................... L040A: .byte $00, $00, $F0, $01, $00 ;....................#####............... L040F: .byte $00, $00, $00, $3E, $00 ;.........................#####.......... L0414: .byte $00, $00, $00, $C0, $07 ;..............................#####..... L0419: .byte $00, $00, $00, $00, $F8 ;...................................##### L041E: .byte $00 ;unused ;------------------------------------------------------------------------------ ; CoinSwitch - Watch the coin switch; count a coin on the press edge. ;------------------------------------------------------------------------------ CoinSwitch: L041F: LXI H,COIN_SW_PREV L0422: IN INP_SWITCH ;Coin switch is active low L0424: CMA L0425: ANI $40 L0427: MOV B,A L0428: XRA M ;Changed? L0429: RZ ;No L042A: MOV M,B ;Remember the new state L042B: MOV A,B L042C: ANA A L042D: RZ ;Released L042E: LXI H,OUT3_SHADOW L0431: MOV A,M L0432: ORI $01 ;Coin counter on L0434: MOV M,A L0435: MVI A,$0A ;for 10 odd frames (TMR_COIN_CTR turns it off) L0437: STA TMR_COIN_CTR L043A: LXI H,COINS L043D: INR M ;One more coin L043E: RET ;------------------------------------------------------------------------------ ; CheckContact - Did the flyer's last picture touch anything? ; Looks at the background bytes DrawFlyer saved (3 per row). Only the 16 ; pixels in the middle of the 24 count: the high nibble of byte 0, all of byte ; 1, the low nibble of byte 2. The first row with a set pixel gives ; CONTACT_ROW = row + 1, which HandleContact (main loop) acts on. ;------------------------------------------------------------------------------ CheckContact: L043F: LDA TMR_HIT_LOCKOUT ;Just launched or just popped a balloon: ignore L0442: ANA A L0443: RNZ L0444: LHLD FLYER_PTR ;The flyer L0447: MOV A,M L0448: ANA A L0449: RP ;Not in use L044A: ANI $60 ;Drawn since it was last erased? L044C: RZ L044D: MOV A,M L044E: ANI $08 ;Splatted L0450: RNZ L0451: LXI B,CL_ROWS L0454: DAD B L0455: MOV C,M ;C = rows drawn L0456: MOV B,C L0457: INX H ;Skip the width L0458: INX H L0459: MOV A,M ;Row: high nibble of the first byte L045A: ANI $F0 L045C: INX H L045D: ORA M ;and the whole second byte L045E: JNZ L046E ;Something was there L0461: INX H L0462: MOV A,M L0463: ANI $0F ;Low nibble of the third byte L0465: JNZ L046E L0468: INX H L0469: DCR B L046A: JNZ L0459 ;Next row L046D: RET L046E: MOV A,C ;Rows done before this one, L046F: SUB B L0470: INR A ;+ 1 L0471: STA CONTACT_ROW L0474: RET L0475: .byte $00 ;unused ;============================================================================== ; SECTION 3 Drawing ($0476-$0A40) ; Text, the screen address calculation, and the erase / draw routines for the ; two clowns with their pictures. Sprites are positioned to the pixel with the ; MB14241 shifter: OUT_SHIFT_AMT gets X AND 7, each picture byte goes to ; OUT_SHIFT_DATA and the shifted byte is read from INP_SHIFT; a final 0 pushes ; out the bits that spill into the next screen byte. ;============================================================================== ;------------------------------------------------------------------------------ ; EraseSeesaw - Blank the seesaw where it was last drawn and take its new X. ; SEESAW_X = PADDLE_POS limited to $D7. The area blanked is 48 pixels wide and ; 16 lines up from line 211, which also removes the rider. The code blanks ; only the 8 seesaw lines when the rider's state asks for its own box to be ; blanked (b5), but FrameTask calls EraseRider first, which clears that bit, ; so the 8-line case never runs. ;------------------------------------------------------------------------------ EraseSeesaw: L0476: LXI H,SEESAW_STATE L0479: MOV A,M ;On screen? L047A: ANA A L047B: RP L047C: INX H L047D: MOV B,M ;B = X it was drawn at L047E: LDA PADDLE_POS ;Wanted X L0481: CPI $D8 ;Limit to $D7 (40-pixel seesaw, 256-pixel screen) L0483: JC L0488 L0486: MVI A,$D7 L0488: STA SEESAW_X ;New X L048B: MOV M,A ;for the next draw L048C: MOV A,B ;Old X / 8 L048D: RAR L048E: RAR L048F: RAR L0490: ANI $1F L0492: ORI $60 ;+ $60: L0494: MOV E,A L0495: MVI D,$3E ;DE = $3E60 + X/8: line 211 L0497: LHLD RIDER_PTR ;The rider L049A: MOV A,M L049B: ANI $20 ;still to blank its own box? L049D: LXI B,$0010 ;B = 0, 16 lines L04A0: JZ L04A5 ;No (always): seesaw and rider L04A3: MVI C,$08 ;Yes: the 8 seesaw lines only (never reached) L04A5: XCHG L04A6: LXI D,$FFDB ;One line up (-37 after 5 steps) L04A9: MOV M,B ;Six bytes of zeros L04AA: INX H L04AB: MOV M,B L04AC: INX H L04AD: MOV M,B L04AE: INX H L04AF: MOV M,B L04B0: INX H L04B1: MOV M,B L04B2: INX H L04B3: MOV M,B L04B4: DAD D L04B5: DCR C L04B6: JNZ L04A9 ;Next line up L04B9: RET L04BA: .byte $00 ;unused ;------------------------------------------------------------------------------ ; DrawString - Draw A characters from HL at screen address DE. ; Characters are 8 x 10 pixels at byte columns (no shifter), 1 byte per ; character: '0'-'9', '@' (blank), 'A'-'W'. The font has no X Y Z: the Q ; glyph is drawn as Y and the K glyph is a down arrow. A code below '0' skips ; ('0' - code) columns instead, moving 16 lines down when it runs into the ; next screen line. The ten glyph rows go to the ten lines below DE's own line ; (the first row is written at DE + 32). Returns DE after the last character, ; HL after the last byte read and A = 0. ;------------------------------------------------------------------------------ DrawString: L04BB: PUSH PSW ;Characters left L04BC: MOV A,M ;Next character L04BD: INX H L04BE: SUI $30 ;'0' and up? L04C0: JP L04D4 ;Yes: draw it L04C3: MOV B,A ;B = minus the columns to skip L04C4: INX D ;One column right L04C5: MOV A,E ;Wrapped onto the next screen line? L04C6: ANI $1F L04C8: JNZ L04CD ;No L04CB: INR D ;Yes: 512 bytes = 16 lines further down L04CC: INR D L04CD: INR B L04CE: JNZ L04C4 ;More columns L04D1: JMP L04BC ;The skip does not count as a character L04D4: PUSH H L04D5: PUSH D L04D6: CALL GlyphAddr ;DE = glyph, HL = screen address, B = 0 L04D9: MVI C,$20 ;32 bytes per screen line L04DB: DAD B ;The first row goes one line below DE L04DC: MVI A,$0A ;10 rows L04DE: PUSH PSW L04DF: LDAX D ;Glyph row L04E0: INX D L04E1: MOV M,A ;straight to the screen L04E2: DAD B ;Next line L04E3: POP PSW L04E4: DCR A L04E5: JNZ L04DE L04E8: POP D L04E9: POP H L04EA: INX D ;Next column L04EB: POP PSW L04EC: DCR A L04ED: JNZ DrawString ;More characters L04F0: RET ;------------------------------------------------------------------------------ ; DrawBigString - Draw A characters from HL at DE, four times as wide and on every other line. ; Each glyph bit becomes 4 pixels and each glyph row is written to one line of ; a pair, so a character is 32 pixels wide and 20 lines tall with the lines ; between left as they are. The next character starts 4 bytes to the right. ;------------------------------------------------------------------------------ DrawBigString: L04F1: PUSH PSW L04F2: MOV A,M ;Character L04F3: SUI $30 ;(no skip codes here) L04F5: INX H L04F6: PUSH H L04F7: CALL GlyphAddr ;DE = glyph, HL = screen address, B = 0 L04FA: MVI A,$0A ;10 rows L04FC: PUSH H L04FD: PUSH PSW L04FE: LDAX D ;Glyph row L04FF: INX D L0500: CALL TwoBitsWide ;Two bits -> one screen byte, four times L0503: CALL TwoBitsWide L0506: CALL TwoBitsWide L0509: CALL TwoBitsWide L050C: POP PSW L050D: POP H L050E: MVI C,$40 ;Two lines down from the start of this row L0510: DAD B L0511: DCR A L0512: JNZ L04FC L0515: LXI B,$FD84 ;Back up the 20 lines and right 4 bytes L0518: DAD B L0519: XCHG ;DE = next screen position L051A: POP H L051B: POP PSW L051C: DCR A L051D: JNZ DrawBigString ;More characters L0520: RET ;------------------------------------------------------------------------------ ; TwoBitsWide - Low two bits of A, each widened to 4 pixels, as one screen byte at HL. ;------------------------------------------------------------------------------ TwoBitsWide: L0521: RAR ;Bit 0 -> L0522: MVI C,$00 L0524: JNC L0529 L0527: MVI C,$0F ;pixels 0-3 L0529: RAR ;Bit 1 -> L052A: PUSH PSW L052B: MVI A,$00 L052D: JNC L0532 L0530: MVI A,$F0 ;pixels 4-7 L0532: ORA C L0533: MOV M,A L0534: INX H L0535: POP PSW L0536: RET ;------------------------------------------------------------------------------ ; ScreenAddr - DE = video RAM address of pixel X = E, Y = D. ; (Y * 256 + X) / 8 + $2400. Leaves B = 0. ;------------------------------------------------------------------------------ ScreenAddr: L0537: MVI B,$03 ;Three shifts L0539: XRA A L053A: MOV A,D ;DE >> 1 L053B: RAR L053C: MOV D,A L053D: MOV A,E L053E: RAR L053F: MOV E,A L0540: DCR B L0541: JNZ L0539 L0544: MOV A,D L0545: ADI $24 ;+ $2400 L0547: MOV D,A L0548: RET ;------------------------------------------------------------------------------ ; GlyphAddr - DE = font glyph for character code A - '0'; HL = the old DE; B = 0. ; Digits are glyphs 1-10, '@' 11, 'A'-'W' 12-34: the six codes between '9' ; and '@' are skipped. DrawString relies on the XCHG to get its screen address ; into HL. ;------------------------------------------------------------------------------ GlyphAddr: L0549: INR A ;Glyph numbers start at 1 L054A: CPI $0B ;A digit? L054C: JM L0551 L054F: SUI $06 ;No: skip the six codes ':' to '?' L0551: LXI H,Font-10 ;Glyph 1 is at Font L0554: LXI B,$000A ;Ten bytes per glyph L0557: DAD B L0558: DCR A L0559: JNZ L0557 L055C: XCHG ;DE = glyph, HL = caller's DE L055D: RET ;------------------------------------------------------------------------------ ; Font - 34 glyphs of 10 rows, one byte per row, bit 0 at the left. ; '0'-'9', '@' (blank), 'A'-'W'. The Q position holds a Y and the K position a ; down arrow. ;------------------------------------------------------------------------------ Font: L055E: .byte $3C ;..####.. '0' (0) L055F: .byte $7E ;.######. L0560: .byte $66 ;.##..##. L0561: .byte $66 ;.##..##. L0562: .byte $66 ;.##..##. L0563: .byte $66 ;.##..##. L0564: .byte $66 ;.##..##. L0565: .byte $66 ;.##..##. L0566: .byte $7E ;.######. L0567: .byte $3C ;..####.. L0568: .byte $18 ;...##... '1' (1) L0569: .byte $1C ;..###... L056A: .byte $18 ;...##... L056B: .byte $18 ;...##... L056C: .byte $18 ;...##... L056D: .byte $18 ;...##... L056E: .byte $18 ;...##... L056F: .byte $18 ;...##... L0570: .byte $3C ;..####.. L0571: .byte $3C ;..####.. L0572: .byte $3C ;..####.. '2' (2) L0573: .byte $7E ;.######. L0574: .byte $66 ;.##..##. L0575: .byte $60 ;.....##. L0576: .byte $7C ;..#####. L0577: .byte $3E ;.#####.. L0578: .byte $06 ;.##..... L0579: .byte $06 ;.##..... L057A: .byte $7E ;.######. L057B: .byte $7E ;.######. L057C: .byte $3C ;..####.. '3' (3) L057D: .byte $7E ;.######. L057E: .byte $66 ;.##..##. L057F: .byte $60 ;.....##. L0580: .byte $38 ;...###.. L0581: .byte $78 ;...####. L0582: .byte $60 ;.....##. L0583: .byte $66 ;.##..##. L0584: .byte $7E ;.######. L0585: .byte $3C ;..####.. L0586: .byte $66 ;.##..##. '4' (4) L0587: .byte $66 ;.##..##. L0588: .byte $66 ;.##..##. L0589: .byte $66 ;.##..##. L058A: .byte $7E ;.######. L058B: .byte $7E ;.######. L058C: .byte $60 ;.....##. L058D: .byte $60 ;.....##. L058E: .byte $60 ;.....##. L058F: .byte $60 ;.....##. L0590: .byte $3E ;.#####.. '5' (5) L0591: .byte $3E ;.#####.. L0592: .byte $06 ;.##..... L0593: .byte $06 ;.##..... L0594: .byte $3E ;.#####.. L0595: .byte $7E ;.######. L0596: .byte $60 ;.....##. L0597: .byte $66 ;.##..##. L0598: .byte $7E ;.######. L0599: .byte $3C ;..####.. L059A: .byte $3C ;..####.. '6' (6) L059B: .byte $3E ;.#####.. L059C: .byte $06 ;.##..... L059D: .byte $06 ;.##..... L059E: .byte $3E ;.#####.. L059F: .byte $7E ;.######. L05A0: .byte $66 ;.##..##. L05A1: .byte $66 ;.##..##. L05A2: .byte $7E ;.######. L05A3: .byte $3C ;..####.. L05A4: .byte $7E ;.######. '7' (7) L05A5: .byte $7E ;.######. L05A6: .byte $60 ;.....##. L05A7: .byte $70 ;....###. L05A8: .byte $30 ;....##.. L05A9: .byte $38 ;...###.. L05AA: .byte $18 ;...##... L05AB: .byte $1C ;..###... L05AC: .byte $0C ;..##.... L05AD: .byte $0C ;..##.... L05AE: .byte $3C ;..####.. '8' (8) L05AF: .byte $7E ;.######. L05B0: .byte $66 ;.##..##. L05B1: .byte $66 ;.##..##. L05B2: .byte $3C ;..####.. L05B3: .byte $7E ;.######. L05B4: .byte $66 ;.##..##. L05B5: .byte $66 ;.##..##. L05B6: .byte $7E ;.######. L05B7: .byte $3C ;..####.. L05B8: .byte $3C ;..####.. '9' (9) L05B9: .byte $7E ;.######. L05BA: .byte $66 ;.##..##. L05BB: .byte $66 ;.##..##. L05BC: .byte $7E ;.######. L05BD: .byte $7C ;..#####. L05BE: .byte $60 ;.....##. L05BF: .byte $60 ;.....##. L05C0: .byte $7C ;..#####. L05C1: .byte $3C ;..####.. L05C2: .byte $00 ;........ '@' (blank) L05C3: .byte $00 ;........ L05C4: .byte $00 ;........ L05C5: .byte $00 ;........ L05C6: .byte $00 ;........ L05C7: .byte $00 ;........ L05C8: .byte $00 ;........ L05C9: .byte $00 ;........ L05CA: .byte $00 ;........ L05CB: .byte $00 ;........ L05CC: .byte $18 ;...##... 'A' (A) L05CD: .byte $3C ;..####.. L05CE: .byte $7E ;.######. L05CF: .byte $66 ;.##..##. L05D0: .byte $66 ;.##..##. L05D1: .byte $66 ;.##..##. L05D2: .byte $7E ;.######. L05D3: .byte $7E ;.######. L05D4: .byte $66 ;.##..##. L05D5: .byte $66 ;.##..##. L05D6: .byte $3E ;.#####.. 'B' (B) L05D7: .byte $7E ;.######. L05D8: .byte $66 ;.##..##. L05D9: .byte $66 ;.##..##. L05DA: .byte $3E ;.#####.. L05DB: .byte $7E ;.######. L05DC: .byte $66 ;.##..##. L05DD: .byte $66 ;.##..##. L05DE: .byte $7E ;.######. L05DF: .byte $3E ;.#####.. L05E0: .byte $3C ;..####.. 'C' (C) L05E1: .byte $7E ;.######. L05E2: .byte $66 ;.##..##. L05E3: .byte $06 ;.##..... L05E4: .byte $06 ;.##..... L05E5: .byte $06 ;.##..... L05E6: .byte $06 ;.##..... L05E7: .byte $66 ;.##..##. L05E8: .byte $7E ;.######. L05E9: .byte $3C ;..####.. L05EA: .byte $3E ;.#####.. 'D' (D) L05EB: .byte $7E ;.######. L05EC: .byte $66 ;.##..##. L05ED: .byte $66 ;.##..##. L05EE: .byte $66 ;.##..##. L05EF: .byte $66 ;.##..##. L05F0: .byte $66 ;.##..##. L05F1: .byte $66 ;.##..##. L05F2: .byte $7E ;.######. L05F3: .byte $3E ;.#####.. L05F4: .byte $7E ;.######. 'E' (E) L05F5: .byte $7E ;.######. L05F6: .byte $06 ;.##..... L05F7: .byte $06 ;.##..... L05F8: .byte $3E ;.#####.. L05F9: .byte $3E ;.#####.. L05FA: .byte $06 ;.##..... L05FB: .byte $06 ;.##..... L05FC: .byte $7E ;.######. L05FD: .byte $7E ;.######. L05FE: .byte $7E ;.######. 'F' (F) L05FF: .byte $7E ;.######. L0600: .byte $06 ;.##..... L0601: .byte $06 ;.##..... L0602: .byte $3E ;.#####.. L0603: .byte $3E ;.#####.. L0604: .byte $06 ;.##..... L0605: .byte $06 ;.##..... L0606: .byte $06 ;.##..... L0607: .byte $06 ;.##..... L0608: .byte $3C ;..####.. 'G' (G) L0609: .byte $7E ;.######. L060A: .byte $66 ;.##..##. L060B: .byte $06 ;.##..... L060C: .byte $06 ;.##..... L060D: .byte $76 ;.##.###. L060E: .byte $76 ;.##.###. L060F: .byte $66 ;.##..##. L0610: .byte $7E ;.######. L0611: .byte $3C ;..####.. L0612: .byte $66 ;.##..##. 'H' (H) L0613: .byte $66 ;.##..##. L0614: .byte $66 ;.##..##. L0615: .byte $66 ;.##..##. L0616: .byte $7E ;.######. L0617: .byte $7E ;.######. L0618: .byte $66 ;.##..##. L0619: .byte $66 ;.##..##. L061A: .byte $66 ;.##..##. L061B: .byte $66 ;.##..##. L061C: .byte $3C ;..####.. 'I' (I) L061D: .byte $3C ;..####.. L061E: .byte $18 ;...##... L061F: .byte $18 ;...##... L0620: .byte $18 ;...##... L0621: .byte $18 ;...##... L0622: .byte $18 ;...##... L0623: .byte $18 ;...##... L0624: .byte $3C ;..####.. L0625: .byte $3C ;..####.. L0626: .byte $60 ;.....##. 'J' (J) L0627: .byte $60 ;.....##. L0628: .byte $60 ;.....##. L0629: .byte $60 ;.....##. L062A: .byte $60 ;.....##. L062B: .byte $60 ;.....##. L062C: .byte $60 ;.....##. L062D: .byte $66 ;.##..##. L062E: .byte $7E ;.######. L062F: .byte $3C ;..####.. L0630: .byte $18 ;...##... 'K' (K, drawn as a down arrow) L0631: .byte $18 ;...##... L0632: .byte $18 ;...##... L0633: .byte $18 ;...##... L0634: .byte $18 ;...##... L0635: .byte $99 ;#..##..# L0636: .byte $FF ;######## L0637: .byte $7E ;.######. L0638: .byte $3C ;..####.. L0639: .byte $18 ;...##... L063A: .byte $06 ;.##..... 'L' (L) L063B: .byte $06 ;.##..... L063C: .byte $06 ;.##..... L063D: .byte $06 ;.##..... L063E: .byte $06 ;.##..... L063F: .byte $06 ;.##..... L0640: .byte $06 ;.##..... L0641: .byte $06 ;.##..... L0642: .byte $7E ;.######. L0643: .byte $7E ;.######. L0644: .byte $C3 ;##....## 'M' (M) L0645: .byte $C3 ;##....## L0646: .byte $E7 ;###..### L0647: .byte $E7 ;###..### L0648: .byte $FF ;######## L0649: .byte $FF ;######## L064A: .byte $DB ;##.##.## L064B: .byte $C3 ;##....## L064C: .byte $C3 ;##....## L064D: .byte $C3 ;##....## L064E: .byte $66 ;.##..##. 'N' (N) L064F: .byte $66 ;.##..##. L0650: .byte $6E ;.###.##. L0651: .byte $6E ;.###.##. L0652: .byte $7E ;.######. L0653: .byte $7E ;.######. L0654: .byte $76 ;.##.###. L0655: .byte $76 ;.##.###. L0656: .byte $66 ;.##..##. L0657: .byte $66 ;.##..##. L0658: .byte $3C ;..####.. 'O' (O) L0659: .byte $7E ;.######. L065A: .byte $66 ;.##..##. L065B: .byte $66 ;.##..##. L065C: .byte $66 ;.##..##. L065D: .byte $66 ;.##..##. L065E: .byte $66 ;.##..##. L065F: .byte $66 ;.##..##. L0660: .byte $7E ;.######. L0661: .byte $3C ;..####.. L0662: .byte $3E ;.#####.. 'P' (P) L0663: .byte $7E ;.######. L0664: .byte $66 ;.##..##. L0665: .byte $66 ;.##..##. L0666: .byte $7E ;.######. L0667: .byte $3E ;.#####.. L0668: .byte $06 ;.##..... L0669: .byte $06 ;.##..... L066A: .byte $06 ;.##..... L066B: .byte $06 ;.##..... L066C: .byte $66 ;.##..##. 'Q' (Q, drawn as Y) L066D: .byte $66 ;.##..##. L066E: .byte $7E ;.######. L066F: .byte $3C ;..####.. L0670: .byte $18 ;...##... L0671: .byte $18 ;...##... L0672: .byte $18 ;...##... L0673: .byte $18 ;...##... L0674: .byte $18 ;...##... L0675: .byte $18 ;...##... L0676: .byte $3E ;.#####.. 'R' (R) L0677: .byte $7E ;.######. L0678: .byte $66 ;.##..##. L0679: .byte $66 ;.##..##. L067A: .byte $7E ;.######. L067B: .byte $3E ;.#####.. L067C: .byte $76 ;.##.###. L067D: .byte $66 ;.##..##. L067E: .byte $66 ;.##..##. L067F: .byte $66 ;.##..##. L0680: .byte $3C ;..####.. 'S' (S) L0681: .byte $7E ;.######. L0682: .byte $66 ;.##..##. L0683: .byte $06 ;.##..... L0684: .byte $3E ;.#####.. L0685: .byte $7C ;..#####. L0686: .byte $60 ;.....##. L0687: .byte $66 ;.##..##. L0688: .byte $7E ;.######. L0689: .byte $3C ;..####.. L068A: .byte $7E ;.######. 'T' (T) L068B: .byte $7E ;.######. L068C: .byte $18 ;...##... L068D: .byte $18 ;...##... L068E: .byte $18 ;...##... L068F: .byte $18 ;...##... L0690: .byte $18 ;...##... L0691: .byte $18 ;...##... L0692: .byte $18 ;...##... L0693: .byte $18 ;...##... L0694: .byte $66 ;.##..##. 'U' (U) L0695: .byte $66 ;.##..##. L0696: .byte $66 ;.##..##. L0697: .byte $66 ;.##..##. L0698: .byte $66 ;.##..##. L0699: .byte $66 ;.##..##. L069A: .byte $66 ;.##..##. L069B: .byte $66 ;.##..##. L069C: .byte $7E ;.######. L069D: .byte $3C ;..####.. L069E: .byte $66 ;.##..##. 'V' (V) L069F: .byte $66 ;.##..##. L06A0: .byte $66 ;.##..##. L06A1: .byte $66 ;.##..##. L06A2: .byte $66 ;.##..##. L06A3: .byte $7E ;.######. L06A4: .byte $3C ;..####.. L06A5: .byte $3C ;..####.. L06A6: .byte $18 ;...##... L06A7: .byte $18 ;...##... L06A8: .byte $C3 ;##....## 'W' (W) L06A9: .byte $C3 ;##....## L06AA: .byte $C3 ;##....## L06AB: .byte $DB ;##.##.## L06AC: .byte $FF ;######## L06AD: .byte $FF ;######## L06AE: .byte $E7 ;###..### L06AF: .byte $E7 ;###..### L06B0: .byte $C3 ;##....## L06B1: .byte $C3 ;##....## ;============================================================================== ; Clown objects ($06B2-$0A40) ; A clown object (CL_ offsets in clowns_defines.asm) remembers where it was ; drawn so that the next update can take the picture off again: either by ; blanking its box (CL_STATE b5) or by putting back the background bytes saved ; while it was drawn (b6). ;============================================================================== ;------------------------------------------------------------------------------ ; EraseFlyer - Remove the object's last picture, as its state bits ask. ; b5: blank the box (BlankBox). Else b6: put the saved background back; a slow ; object (b4) only does so on every 4th call. ;------------------------------------------------------------------------------ EraseFlyer: L06B2: MOV A,M L06B3: ANI $20 ;Blank the box? L06B5: JZ RestoreBackground ;No ;------------------------------------------------------------------------------ ; BlankBox - Write zeros over the object's box and clear state b5. ;------------------------------------------------------------------------------ BlankBox: L06B8: MOV A,M L06B9: ANI $DF ;Request done L06BB: CALL ObjectBox ;DE = screen address, C = rows, HL -> width L06BE: MOV A,M ;Screen bytes per row L06BF: XCHG ;HL = screen address L06C0: DCR A ;Two bytes per row? L06C1: DCR A L06C2: MOV A,C L06C3: JNZ L06D1 ;No: three L06C6: MVI C,$1F ;To the next line: 32 - 1 L06C8: MOV M,B L06C9: INX H L06CA: MOV M,B L06CB: DAD B L06CC: DCR A L06CD: JNZ L06C8 ;Next row L06D0: RET L06D1: MVI C,$1E ;To the next line: 32 - 2 L06D3: MOV M,B L06D4: INX H L06D5: MOV M,B L06D6: INX H L06D7: MOV M,B L06D8: DAD B L06D9: DCR A L06DA: JNZ L06D3 ;Next row L06DD: RET RestoreBackground: L06DE: MOV A,M L06DF: ANI $40 ;Put the background back? L06E1: RZ ;No: nothing to remove L06E2: MOV A,M L06E3: ANI $10 ;Slow object? L06E5: JZ L06F1 ;No L06E8: INR M ;Count its updates L06E9: MOV A,M L06EA: ANI $03 ;Every 4th one only L06EC: RNZ L06ED: MOV A,M L06EE: ANI $F8 ;Tick back to 0 L06F0: MOV M,A L06F1: MOV A,M L06F2: ANI $BF ;Request done L06F4: CALL ObjectBox ;DE = screen address, C = rows L06F7: INX H ;HL -> saved bytes L06F8: XCHG ;HL = screen, DE = saved bytes L06F9: LDAX D ;Three bytes per row L06FA: INX D L06FB: MOV M,A L06FC: INX H L06FD: LDAX D L06FE: INX D L06FF: MOV M,A L0700: INX H L0701: LDAX D L0702: INX D L0703: MOV M,A L0704: MOV A,C L0705: MVI C,$1E ;To the next line: 32 - 2 L0707: DAD B L0708: MOV C,A L0709: DCR C L070A: JNZ L06F9 ;Next row L070D: RET ;------------------------------------------------------------------------------ ; ObjectBox - Store A as the object's state; DE = its screen address, C = rows, HL -> width, B = 0. ;------------------------------------------------------------------------------ ObjectBox: L070E: MOV M,A L070F: LXI B,CL_SCREEN L0712: DAD B L0713: MOV E,M L0714: INX H L0715: MOV D,M L0716: INX H L0717: MOV C,M L0718: INX H L0719: RET ;------------------------------------------------------------------------------ ; EraseRider - Blank the rider's old box if its state asks for it. ;------------------------------------------------------------------------------ EraseRider: L071A: MOV A,M L071B: ANI $20 ;Only set when it has just landed as the flyer L071D: RZ L071E: JMP BlankBox ;Blank the box ;------------------------------------------------------------------------------ ; DrawFlyer - Move the flying clown and draw it. ; X += XVEL, turning back when the result is $F2 or more (past the right edge, ; or below 0 at the left); Y += YVEL, turning back when the result is $F0 or ; more (above the top). The picture CL_FRAME (2 bytes ; wide) is OR-ed into the screen through the shifter, 3 screen bytes per row; ; the bytes that were there are saved in the object first, both for ; RestoreBackground and for CheckContact. ERASE_MODE is OR-ed into the state ; so that the next update takes the picture off again. A slow object (b4) is ; only drawn when its tick is 0. ;------------------------------------------------------------------------------ DrawFlyer: L0721: MOV A,M L0722: ANA A L0723: RP ;Not in use L0724: ANI $10 ;Slow object? L0726: JZ L072D L0729: MOV A,M L072A: ANI $03 ;Yes: only on tick 0 L072C: RNZ L072D: LDA ERASE_MODE ;How to erase this picture next time L0730: ORA M L0731: MOV M,A L0732: INX H L0733: MOV C,M ;C = picture number L0734: INX H L0735: MOV A,M ;X velocity L0736: INX H L0737: ADD M ;+ X L0738: CPI $F2 ;Off either edge? L073A: JC L0745 ;No L073D: DCX H ;Yes: reverse the X velocity L073E: MOV A,M L073F: CMA L0740: INR A L0741: MOV M,A L0742: JMP L0736 ;and try again L0745: MOV M,A ;New X L0746: MOV E,A L0747: ANI $07 ;X within the byte L0749: OUT OUT_SHIFT_AMT ;to the shifter L074B: INX H L074C: MOV A,M ;Y velocity L074D: INX H L074E: ADD M ;+ Y L074F: CPI $F0 ;Above the top? L0751: JC L075B ;No L0754: DCX H ;Yes: reverse the Y velocity L0755: MOV A,M L0756: CMA L0757: INR A L0758: MOV M,A L0759: INX H L075A: MOV A,M ;and stay at the same Y L075B: MOV M,A ;New Y L075C: MOV D,A L075D: INX H L075E: CALL ScreenAddr ;DE = screen address, B = 0 L0761: MOV M,E ;Remember it for the erase L0762: INX H L0763: MOV M,D L0764: INX H L0765: PUSH H L0766: LXI H,ClownPictures ;Picture pointers L0769: DAD B L076A: DAD B L076B: MOV C,M ;BC = picture L076C: INX H L076D: MOV B,M L076E: POP H L076F: LDAX B ;Rows L0770: INX B L0771: PUSH PSW L0772: MOV M,A ;CL_ROWS L0773: INX H L0774: LDAX B ;Picture bytes per row (always 2) L0775: INX B L0776: MOV M,A L0777: INR M ;CL_WIDTH: one more on screen L0778: INX H L0779: XCHG ;HL = screen, DE -> CL_SAVED L077A: POP PSW L077B: PUSH PSW L077C: MOV A,M ;Save the background byte L077D: STAX D L077E: INX D L077F: LDAX B ;First picture byte L0780: INX B L0781: OUT OUT_SHIFT_DATA L0783: IN INP_SHIFT L0785: ORA M ;OR it in L0786: MOV M,A L0787: INX H L0788: MOV A,M ;Second background byte L0789: STAX D L078A: INX D L078B: LDAX B ;Second picture byte L078C: INX B L078D: OUT OUT_SHIFT_DATA L078F: IN INP_SHIFT L0791: ORA M L0792: MOV M,A L0793: INX H L0794: MOV A,M ;Third background byte L0795: STAX D L0796: INX D L0797: XRA A ;Flush the shifter: L0798: OUT OUT_SHIFT_DATA L079A: IN INP_SHIFT L079C: ORA M ;the spill of the second byte L079D: MOV M,A L079E: PUSH B L079F: LXI B,$001E ;To the next line: 32 - 2 L07A2: DAD B L07A3: POP B L07A4: POP PSW L07A5: DCR A L07A6: JNZ L077B ;Next row L07A9: RET ;------------------------------------------------------------------------------ ; DrawRider - Draw the clown that stands on the seesaw. ; It stands on the low end: at SEESAW_X + $22 when the right end is down, at ; SEESAW_X otherwise (while the seesaw tips, b5 and b6 both set, it is already ; drawn on the left). One fixed picture, 8 pixels wide, 15 rows; the ; background is saved as for the flyer but is never put back - EraseSeesaw ; blanks the whole area. ;------------------------------------------------------------------------------ DrawRider: L07AA: MOV A,M L07AB: ANA A L07AC: RP ;Not in use L07AD: INX H L07AE: INX H L07AF: INX H ;HL -> CL_X L07B0: LDA SEESAW_STATE L07B3: ANI $60 ;Right end down and not tipping? L07B5: MVI D,$22 ;Yes: 34 pixels right of the seesaw's left end L07B7: JPO L07BC ;(parity odd = exactly one of b5 b6) L07BA: MVI D,$00 ;No: at the left end L07BC: LDA SEESAW_X L07BF: ADD D ;+ seesaw X L07C0: MOV E,A L07C1: ANI $07 ;X within the byte L07C3: OUT OUT_SHIFT_AMT ;to the shifter L07C5: MOV M,E ;CL_X L07C6: INX H L07C7: MOV A,M ;Y velocity L07C8: INX H L07C9: ADD M ;+ Y L07CA: MOV D,A L07CB: MOV M,A ;CL_Y L07CC: INX H L07CD: CALL ScreenAddr ;DE = screen address L07D0: MOV M,E ;Remember it L07D1: INX H L07D2: MOV M,D L07D3: INX H L07D4: MVI A,$0F ;15 rows L07D6: MOV M,A L07D7: INX H L07D8: MVI M,$02 ;2 screen bytes per row L07DA: INX H L07DB: XCHG ;HL = screen, DE -> CL_SAVED L07DC: LXI B,RiderPicture L07DF: PUSH PSW L07E0: MOV A,M ;Save the background byte L07E1: STAX D L07E2: INX D L07E3: LDAX B ;Picture byte L07E4: INX B L07E5: OUT OUT_SHIFT_DATA L07E7: IN INP_SHIFT L07E9: ORA M ;OR it in L07EA: MOV M,A L07EB: INX H L07EC: MOV A,M ;Second background byte L07ED: STAX D L07EE: INX D L07EF: XRA A ;Flush the shifter: the spill L07F0: OUT OUT_SHIFT_DATA L07F2: IN INP_SHIFT L07F4: ORA M L07F5: MOV M,A L07F6: PUSH B L07F7: LXI B,$001F ;To the next line: 32 - 1 L07FA: DAD B L07FB: POP B L07FC: POP PSW L07FD: DCR A L07FE: JNZ L07DF ;Next row L0801: RET ;------------------------------------------------------------------------------ ; RiderPicture - The standing clown, 15 rows of 1 byte. ;------------------------------------------------------------------------------ RiderPicture: L0802: .byte $08 ;...#.... L0803: .byte $1C ;..###... L0804: .byte $1C ;..###... L0805: .byte $1C ;..###... L0806: .byte $08 ;...#.... L0807: .byte $3E ;.#####.. L0808: .byte $5D ;#.###.#. L0809: .byte $5D ;#.###.#. L080A: .byte $3E ;.#####.. L080B: .byte $1C ;..###... L080C: .byte $1C ;..###... L080D: .byte $1C ;..###... L080E: .byte $14 ;..#.#... L080F: .byte $14 ;..#.#... L0810: .byte $36 ;.##.##.. L0811: .byte $00 ;........ (not drawn) ;------------------------------------------------------------------------------ ; ClownPictures - Pointers to the 18 flyer pictures (CL_FRAME). ; $00 standing; $01-$08 tumbling (AnimateFlyer cycles $01-$03, a popped ; balloon picks $01-$08 at random); $09-$0B walking right and $0C-$0E walking ; left (serve); $0F-$11 splat. Each picture is rows, bytes per row (2), then ; the rows. ;------------------------------------------------------------------------------ ClownPictures: L0812: .word ClownStand ;picture $00 L0814: .word ClownTumble1 ;picture $01 L0816: .word ClownTumble2 ;picture $02 L0818: .word ClownTumble3 ;picture $03 L081A: .word ClownTumble4 ;picture $04 L081C: .word ClownTumble5 ;picture $05 L081E: .word ClownTumble6 ;picture $06 L0820: .word ClownTumble7 ;picture $07 L0822: .word ClownTumble8 ;picture $08 L0824: .word ClownWalkR1 ;picture $09 L0826: .word ClownWalkR2 ;picture $0A L0828: .word ClownWalkR3 ;picture $0B L082A: .word ClownWalkL1 ;picture $0C L082C: .word ClownWalkL2 ;picture $0D L082E: .word ClownWalkL3 ;picture $0E L0830: .word ClownSplat1 ;picture $0F L0832: .word ClownSplat2 ;picture $10 L0834: .word ClownSplat3 ;picture $11 ClownWalkR1: L0836: .byte $10, $02 ;16 rows, 2 bytes wide L0838: .byte $40, $00 ;......#......... L083A: .byte $E0, $00 ;.....###........ L083C: .byte $E0, $01 ;.....####....... L083E: .byte $E0, $00 ;.....###........ L0840: .byte $40, $00 ;......#......... L0842: .byte $C0, $00 ;......##........ L0844: .byte $E0, $01 ;.....####....... L0846: .byte $D0, $02 ;....#.##.#...... L0848: .byte $D0, $04 ;....#.##..#..... L084A: .byte $D0, $08 ;....#.##...#.... L084C: .byte $D0, $03 ;....#.####...... L084E: .byte $40, $02 ;......#..#...... L0850: .byte $40, $02 ;......#..#...... L0852: .byte $40, $06 ;......#..##..... L0854: .byte $40, $00 ;......#......... L0856: .byte $C0, $00 ;......##........ ClownWalkR2: L0858: .byte $10, $02 ;16 rows, 2 bytes wide L085A: .byte $40, $00 ;......#......... L085C: .byte $E0, $00 ;.....###........ L085E: .byte $E0, $01 ;.....####....... L0860: .byte $E0, $00 ;.....###........ L0862: .byte $40, $00 ;......#......... L0864: .byte $C0, $00 ;......##........ L0866: .byte $E0, $0F ;.....#######.... L0868: .byte $D0, $00 ;....#.##........ L086A: .byte $C8, $00 ;...#..##........ L086C: .byte $C8, $00 ;...#..##........ L086E: .byte $48, $00 ;...#..#......... L0870: .byte $40, $00 ;......#......... L0872: .byte $40, $00 ;......#......... L0874: .byte $40, $00 ;......#......... L0876: .byte $40, $00 ;......#......... L0878: .byte $C0, $01 ;......###....... ClownWalkR3: L087A: .byte $10, $02 ;16 rows, 2 bytes wide L087C: .byte $80, $00 ;.......#........ L087E: .byte $C0, $01 ;......###....... L0880: .byte $C0, $03 ;......####...... L0882: .byte $C0, $01 ;......###....... L0884: .byte $80, $00 ;.......#........ L0886: .byte $C0, $00 ;......##........ L0888: .byte $E0, $03 ;.....#####...... L088A: .byte $90, $05 ;....#..##.#..... L088C: .byte $88, $09 ;...#...##..#.... L088E: .byte $84, $11 ;..#....##...#... L0890: .byte $C0, $01 ;......###....... L0892: .byte $60, $01 ;.....##.#....... L0894: .byte $20, $01 ;.....#..#....... L0896: .byte $18, $01 ;...##...#....... L0898: .byte $08, $01 ;...#....#....... L089A: .byte $00, $03 ;........##...... ClownWalkL1: L089C: .byte $10, $02 ;16 rows, 2 bytes wide L089E: .byte $80, $00 ;.......#........ L08A0: .byte $C0, $01 ;......###....... L08A2: .byte $E0, $01 ;.....####....... L08A4: .byte $C0, $01 ;......###....... L08A6: .byte $80, $00 ;.......#........ L08A8: .byte $C0, $00 ;......##........ L08AA: .byte $E0, $01 ;.....####....... L08AC: .byte $D0, $02 ;....#.##.#...... L08AE: .byte $C8, $02 ;...#..##.#...... L08B0: .byte $C4, $02 ;..#...##.#...... L08B2: .byte $F0, $00 ;....####........ L08B4: .byte $90, $00 ;....#..#........ L08B6: .byte $90, $00 ;....#..#........ L08B8: .byte $98, $00 ;...##..#........ L08BA: .byte $80, $00 ;.......#........ L08BC: .byte $C0, $00 ;......##........ ClownWalkL2: L08BE: .byte $10, $02 ;16 rows, 2 bytes wide L08C0: .byte $40, $00 ;......#......... L08C2: .byte $E0, $00 ;.....###........ L08C4: .byte $F0, $00 ;....####........ L08C6: .byte $E0, $00 ;.....###........ L08C8: .byte $40, $00 ;......#......... L08CA: .byte $60, $00 ;.....##......... L08CC: .byte $FE, $00 ;.#######........ L08CE: .byte $60, $01 ;.....##.#....... L08D0: .byte $60, $02 ;.....##..#...... L08D2: .byte $60, $02 ;.....##..#...... L08D4: .byte $40, $02 ;......#..#...... L08D6: .byte $40, $00 ;......#......... L08D8: .byte $40, $00 ;......#......... L08DA: .byte $40, $00 ;......#......... L08DC: .byte $40, $00 ;......#......... L08DE: .byte $60, $00 ;.....##......... ClownWalkL3: L08E0: .byte $10, $02 ;16 rows, 2 bytes wide L08E2: .byte $80, $00 ;.......#........ L08E4: .byte $C0, $01 ;......###....... L08E6: .byte $E0, $01 ;.....####....... L08E8: .byte $C0, $01 ;......###....... L08EA: .byte $80, $00 ;.......#........ L08EC: .byte $C0, $00 ;......##........ L08EE: .byte $E0, $03 ;.....#####...... L08F0: .byte $D0, $04 ;....#.##..#..... L08F2: .byte $C8, $08 ;...#..##...#.... L08F4: .byte $C4, $10 ;..#...##....#... L08F6: .byte $C0, $01 ;......###....... L08F8: .byte $40, $03 ;......#.##...... L08FA: .byte $40, $02 ;......#..#...... L08FC: .byte $40, $0C ;......#...##.... L08FE: .byte $40, $08 ;......#....#.... L0900: .byte $60, $00 ;.....##......... ClownTumble1: L0902: .byte $10, $02 ;16 rows, 2 bytes wide L0904: .byte $00, $01 ;........#....... L0906: .byte $80, $03 ;.......###...... L0908: .byte $84, $03 ;..#....###...... L090A: .byte $88, $03 ;...#...###...... L090C: .byte $10, $01 ;....#...#....... L090E: .byte $E0, $07 ;.....######..... L0910: .byte $80, $0B ;.......###.#.... L0912: .byte $80, $13 ;.......###..#... L0914: .byte $80, $23 ;.......###...#.. L0916: .byte $80, $03 ;.......###...... L0918: .byte $E0, $03 ;.....#####...... L091A: .byte $30, $06 ;....##...##..... L091C: .byte $18, $04 ;...##.....#..... L091E: .byte $0C, $04 ;..##......#..... L0920: .byte $00, $04 ;..........#..... L0922: .byte $00, $0C ;..........##.... ClownTumble2: L0924: .byte $0E, $02 ;14 rows, 2 bytes wide L0926: .byte $00, $01 ;........#....... L0928: .byte $80, $03 ;.......###...... L092A: .byte $84, $43 ;..#....###....#. L092C: .byte $88, $23 ;...#...###...#.. L092E: .byte $10, $11 ;....#...#...#... L0930: .byte $E0, $0F ;.....#######.... L0932: .byte $80, $03 ;.......###...... L0934: .byte $80, $03 ;.......###...... L0936: .byte $80, $03 ;.......###...... L0938: .byte $80, $03 ;.......###...... L093A: .byte $C0, $07 ;......#####..... L093C: .byte $60, $0C ;.....##...##.... L093E: .byte $30, $18 ;....##.....##... L0940: .byte $18, $30 ;...##.......##.. ClownTumble3: L0942: .byte $0F, $02 ;15 rows, 2 bytes wide L0944: .byte $80, $00 ;.......#........ L0946: .byte $C0, $01 ;......###....... L0948: .byte $C0, $21 ;......###....#.. L094A: .byte $C0, $11 ;......###...#... L094C: .byte $80, $08 ;.......#...#.... L094E: .byte $E0, $07 ;.....######..... L0950: .byte $D0, $01 ;....#.###....... L0952: .byte $C8, $01 ;...#..###....... L0954: .byte $C4, $01 ;..#...###....... L0956: .byte $C0, $01 ;......###....... L0958: .byte $E0, $03 ;.....#####...... L095A: .byte $60, $06 ;.....##..##..... L095C: .byte $60, $0C ;.....##...##.... L095E: .byte $20, $18 ;.....#.....##... L0960: .byte $30, $00 ;....##.......... ClownTumble4: L0962: .byte $0C, $02 ;12 rows, 2 bytes wide L0964: .byte $00, $40 ;..............#. L0966: .byte $00, $20 ;.............#.. L0968: .byte $00, $10 ;............#... L096A: .byte $01, $08 ;#..........#.... L096C: .byte $07, $04 ;###.......#..... L096E: .byte $3C, $04 ;..####....#..... L0970: .byte $E0, $77 ;.....######.###. L0972: .byte $E0, $FF ;.....########### L0974: .byte $E0, $77 ;.....######.###. L0976: .byte $38, $04 ;...###....#..... L0978: .byte $1F, $FC ;#####.....###### L097A: .byte $01, $00 ;#............... ClownTumble5: L097C: .byte $0B, $02 ;11 rows, 2 bytes wide L097E: .byte $04, $00 ;..#............. L0980: .byte $08, $00 ;...#............ L0982: .byte $10, $80 ;....#..........# L0984: .byte $20, $E0 ;.....#.......### L0986: .byte $20, $3C ;.....#....####.. L0988: .byte $EE, $07 ;.###.######..... L098A: .byte $FF, $07 ;###########..... L098C: .byte $EE, $07 ;.###.######..... L098E: .byte $20, $1C ;.....#....###... L0990: .byte $3F, $F8 ;######.....##### L0992: .byte $00, $80 ;...............# ClownTumble6: L0994: .byte $10, $02 ;16 rows, 2 bytes wide L0996: .byte $30, $00 ;....##.......... L0998: .byte $20, $00 ;.....#.......... L099A: .byte $20, $30 ;.....#......##.. L099C: .byte $20, $18 ;.....#.....##... L099E: .byte $60, $0C ;.....##...##.... L09A0: .byte $C0, $07 ;......#####..... L09A2: .byte $C0, $01 ;......###....... L09A4: .byte $C4, $01 ;..#...###....... L09A6: .byte $C8, $01 ;...#..###....... L09A8: .byte $D0, $01 ;....#.###....... L09AA: .byte $E0, $07 ;.....######..... L09AC: .byte $80, $08 ;.......#...#.... L09AE: .byte $C0, $11 ;......###...#... L09B0: .byte $C0, $21 ;......###....#.. L09B2: .byte $C0, $01 ;......###....... L09B4: .byte $80, $00 ;.......#........ ClownTumble7: L09B6: .byte $0E, $02 ;14 rows, 2 bytes wide L09B8: .byte $0C, $18 ;..##.......##... L09BA: .byte $18, $0C ;...##.....##.... L09BC: .byte $30, $06 ;....##...##..... L09BE: .byte $E0, $03 ;.....#####...... L09C0: .byte $C0, $01 ;......###....... L09C2: .byte $C0, $01 ;......###....... L09C4: .byte $C0, $01 ;......###....... L09C6: .byte $C0, $01 ;......###....... L09C8: .byte $F0, $07 ;....#######..... L09CA: .byte $88, $08 ;...#...#...#.... L09CC: .byte $C4, $11 ;..#...###...#... L09CE: .byte $C2, $21 ;.#....###....#.. L09D0: .byte $C0, $01 ;......###....... L09D2: .byte $80, $00 ;.......#........ ClownTumble8: L09D4: .byte $0F, $02 ;15 rows, 2 bytes wide L09D6: .byte $00, $0C ;..........##.... L09D8: .byte $18, $04 ;...##.....#..... L09DA: .byte $30, $06 ;....##...##..... L09DC: .byte $60, $06 ;.....##..##..... L09DE: .byte $C0, $07 ;......#####..... L09E0: .byte $80, $03 ;.......###...... L09E2: .byte $80, $23 ;.......###...#.. L09E4: .byte $80, $13 ;.......###..#... L09E6: .byte $80, $0B ;.......###.#.... L09E8: .byte $E0, $07 ;.....######..... L09EA: .byte $10, $01 ;....#...#....... L09EC: .byte $88, $03 ;...#...###...... L09EE: .byte $84, $03 ;..#....###...... L09F0: .byte $80, $03 ;.......###...... L09F2: .byte $00, $01 ;........#....... ClownStand: L09F4: .byte $0F, $02 ;15 rows, 2 bytes wide L09F6: .byte $00, $01 ;........#....... L09F8: .byte $80, $03 ;.......###...... L09FA: .byte $80, $03 ;.......###...... L09FC: .byte $80, $03 ;.......###...... L09FE: .byte $00, $01 ;........#....... L0A00: .byte $C0, $07 ;......#####..... L0A02: .byte $A0, $0B ;.....#.###.#.... L0A04: .byte $A0, $0B ;.....#.###.#.... L0A06: .byte $C0, $07 ;......#####..... L0A08: .byte $80, $03 ;.......###...... L0A0A: .byte $80, $03 ;.......###...... L0A0C: .byte $80, $03 ;.......###...... L0A0E: .byte $80, $02 ;.......#.#...... L0A10: .byte $80, $02 ;.......#.#...... L0A12: .byte $C0, $06 ;......##.##..... ClownSplat1: L0A14: .byte $0A, $02 ;10 rows, 2 bytes wide L0A16: .byte $00, $01 ;........#....... L0A18: .byte $80, $03 ;.......###...... L0A1A: .byte $84, $43 ;..#....###....#. L0A1C: .byte $88, $23 ;...#...###...#.. L0A1E: .byte $10, $11 ;....#...#...#... L0A20: .byte $E0, $0F ;.....#######.... L0A22: .byte $80, $03 ;.......###...... L0A24: .byte $80, $03 ;.......###...... L0A26: .byte $84, $43 ;..#....###....#. L0A28: .byte $FC, $7F ;..#############. ClownSplat2: L0A2A: .byte $06, $02 ;6 rows, 2 bytes wide L0A2C: .byte $00, $01 ;........#....... L0A2E: .byte $80, $03 ;.......###...... L0A30: .byte $80, $03 ;.......###...... L0A32: .byte $84, $43 ;..#....###....#. L0A34: .byte $2C, $69 ;..##.#..#..#.##. L0A36: .byte $FC, $7F ;..#############. ClownSplat3: L0A38: .byte $03, $02 ;3 rows, 2 bytes wide L0A3A: .byte $08, $03 ;...#....##...... L0A3C: .byte $DC, $47 ;..###.#####...#. L0A3E: .byte $FC, $7F ;..#############. L0A40: .byte $00 ;unused ;============================================================================== ; SECTION 4 Main loop and its tasks ($0A41-$0DF3) ; The foreground: a small script interpreter that sequences attract mode and ; the game, and - whenever the script waits - one pass over the game tasks. ; The tasks only change variables and draw text; the interrupts draw the ; moving objects. ;============================================================================== ;------------------------------------------------------------------------------ ; GameStart - Normal power-on: clear all RAM and start the script at AttractScript. ;------------------------------------------------------------------------------ GameStart: L0A41: XRA A ;Tone and sounds off L0A42: OUT OUT_TONE_LO L0A44: OUT OUT_TONE_HI L0A46: OUT OUT_SOUND L0A48: CALL ClearRamTop ;A = 0: all 256 blocks, $2000-$3FFF L0A4B: LXI H,AttractScript ;Script starts with attract mode L0A4E: SHLD SCRIPT_PTR ;------------------------------------------------------------------------------ ; MainLoop - Run script commands until a WAIT, then one pass of the game tasks. ; The script byte at SCRIPT_PTR is an even opcode 2-$20 that indexes ; ScriptOps; the handler gets the address of its arguments in DE and returns ; here (this routine's address is pushed first). Opcode 0 is WAIT: the pointer ; stays on it and the tasks below run every pass until a timer event moves the ; script on (ScriptTimerDone, CheckTimeout). Interrupts are off while commands ; run and back on at a WAIT. ;------------------------------------------------------------------------------ MainLoop: L0A51: LXI H,MainLoop ;Every path returns to MainLoop L0A54: PUSH H L0A55: OUT OUT_WATCHDOG L0A57: LHLD SCRIPT_PTR L0A5A: MOV A,M ;Script opcode L0A5B: ANA A L0A5C: JZ L0A71 ;0 = WAIT: run the game tasks L0A5F: DI ;No interrupts while the script changes things L0A60: INX H L0A61: SHLD SCRIPT_PTR ;Step past the opcode L0A64: XCHG ;DE -> arguments L0A65: LXI H,ScriptOps-2 ;Opcodes start at 2 L0A68: MOV C,A L0A69: MVI B,$00 L0A6B: DAD B ;+ opcode L0A6C: MOV A,M L0A6D: INX H L0A6E: MOV H,M L0A6F: MOV L,A L0A70: PCHL ;To the handler ;WAIT: one pass of the game tasks L0A71: EI L0A72: CALL HandleContact ;Act on what the flyer touched L0A75: CALL FormatScores ;Scores to text, one character to the screen L0A78: CALL RunTimerEvents ;Expired timers L0A7B: CALL RunTimerEvents2 L0A7E: CALL CheckTimeout ;Script timeout L0A81: CALL ServeClown ;New jump wanted? L0A84: CALL AnimateFlyer ;Flyer picture and erase mode L0A87: CALL DrawNextDigit ;Another score character L0A8A: CALL HandleContact ;Contact again: it must not wait a whole pass L0A8D: CALL DrawNextDigit ;Another score character L0A90: CALL ReadStartButtons L0A93: CALL DrawPlayfieldIfOn ;Floor and ledges L0A96: CALL Autopilot ;Attract mode steers the seesaw L0A99: LDA GAME_ACTIVE ;Game on? L0A9C: ANA A L0A9D: RZ ;No L0A9E: CALL DrawNextDigit L0AA1: CALL CheckRowsCleared ;A balloon row emptied? L0AA4: RET ;Back to MainLoop ;------------------------------------------------------------------------------ ; Random - Next 8-bit pseudo-random number in A (and RNG_SEED). ; Shift register: the seed moves right one bit and the parity of its bits 0, 2, ; 3 and 4 comes in at the top. A zero seed is replaced by $FF first. ;------------------------------------------------------------------------------ Random: L0AA5: LXI H,RNG_SEED L0AA8: MVI C,$00 L0AAA: MOV A,M L0AAB: ANA A L0AAC: JNZ L0AB0 ;Seed 0 would stay 0 L0AAF: DCR A L0AB0: MOV B,A L0AB1: ANI $1D ;Taps: bits 0, 2, 3, 4 L0AB3: JPE L0AB8 ;Even parity: shift in 0 L0AB6: MVI C,$80 ;Odd: shift in 1 L0AB8: MOV A,B L0AB9: RRC ;Seed >> 1 L0ABA: ANI $7F L0ABC: ADD C L0ABD: MOV M,A ;New seed L0ABE: RET ;------------------------------------------------------------------------------ ; BalloonTasks - The six odd-frame balloon passes: first balloon, routine. ; A pass moves every other balloon of one row by one pixel, so each balloon ; moves once in 12 frames. Top and bottom rows drift right, the middle row left. ;------------------------------------------------------------------------------ BalloonTasks: L0ABF: .word P1_ROW_TOP, MoveBalloonsRight ;phase 0: even balloons of the top row move right L0AC3: .word P1_ROW_MID, MoveBalloonsLeft ;phase 1: even balloons of the middle row move left L0AC7: .word P1_ROW_BOT, MoveBalloonsRight ;phase 2: even balloons of the bottom row move right L0ACB: .word P1_ROW_TOP+3, MoveBalloonsRight ;phase 3: odd balloons of the top row move right L0ACF: .word P1_ROW_MID+3, MoveBalloonsLeft ;phase 4: odd balloons of the middle row move left L0AD3: .word P1_ROW_BOT+3, MoveBalloonsRight ;phase 5: odd balloons of the bottom row move right ;------------------------------------------------------------------------------ ; AnimateFlyer - Choose the flyer's picture and erase mode from its height. ; Not while it is being served. Y $B0-$BB (coming down on the seesaw): stand ; upright, blank-box erase. Above $B0: erase by restoring the background, and ; from $54 down tumble through pictures 1-3, one step every 7 ticks. In the ; balloon rows (above $54) the picture is left alone. ;------------------------------------------------------------------------------ AnimateFlyer: L0AD7: LDA SERVING ;Walking on its ledge? L0ADA: ANA A L0ADB: RNZ L0ADC: LHLD FLYER_PTR ;The flyer L0ADF: MOV A,M L0AE0: ANA A L0AE1: RP ;Not in use L0AE2: MOV D,H ;DE = the object L0AE3: MOV E,L L0AE4: LXI B,CL_Y L0AE7: DAD B L0AE8: MOV A,M ;Its Y L0AE9: CPI $BC ;Down at the seesaw already L0AEB: RNC L0AEC: CPI $B0 ;Just above the seesaw? L0AEE: JC L0AFA ;No: higher up L0AF1: MVI A,$20 ;Erase by blanking the box L0AF3: STA ERASE_MODE L0AF6: INX D ;CL_FRAME L0AF7: XRA A L0AF8: STAX D ;Picture 0: standing L0AF9: RET L0AFA: CPI $54 ;In the balloon rows? L0AFC: MVI A,$40 ;Higher than the seesaw: erase by restoring the background L0AFE: STA ERASE_MODE L0B01: RC ;Yes: keep the picture L0B02: LXI H,TMR_TUMBLE ;Time for the next tumble picture? L0B05: MOV A,M L0B06: ANA A L0B07: RNZ L0B08: MVI M,$07 ;Every 7 ticks L0B0A: INX D ;CL_FRAME L0B0B: LDAX D L0B0C: INR A L0B0D: CPI $04 ;Pictures 1, 2, 3, 1 ... L0B0F: JC L0B14 L0B12: MVI A,$01 L0B14: STAX D L0B15: RET L0B16: .byte $00 ;unused ;------------------------------------------------------------------------------ ; MoveBalloonsRight - Move six balloons (every other one from DE) one pixel right and redraw them. ;------------------------------------------------------------------------------ MoveBalloonsRight: L0B17: CALL PlayerRow ;HL = first balloon, in the current player's rows L0B1A: MVI A,$06 ;Six balloons L0B1C: PUSH PSW L0B1D: MOV A,M ;State L0B1E: ANA A L0B1F: JP L0B38 ;Popped L0B22: PUSH H L0B23: INX H L0B24: INR M ;X + 1 L0B25: MOV A,M L0B26: MOV E,A L0B27: ANI $07 ;X within the byte L0B29: OUT OUT_SHIFT_AMT ;to the shifter L0B2B: INX H L0B2C: MOV D,M ;Y L0B2D: CALL ScreenAddr ;DE = screen address L0B30: XCHG ;HL = screen address L0B31: LXI D,BalloonRightPic ;Picture with a blank column on the left L0B34: CALL DrawBalloon L0B37: POP H L0B38: LXI D,$0006 ;Skip one balloon L0B3B: DAD D L0B3C: POP PSW L0B3D: DCR A L0B3E: JNZ L0B1C L0B41: RET ;------------------------------------------------------------------------------ ; MoveBalloonsLeft - Move six balloons (every other one from DE) one pixel left and redraw them. ;------------------------------------------------------------------------------ MoveBalloonsLeft: L0B42: CALL PlayerRow L0B45: MVI A,$06 L0B47: PUSH PSW L0B48: MOV A,M L0B49: ANA A L0B4A: JP L0B63 ;Popped L0B4D: PUSH H L0B4E: INX H L0B4F: DCR M ;X - 1 L0B50: MOV A,M L0B51: MOV E,A L0B52: ANI $07 L0B54: OUT OUT_SHIFT_AMT L0B56: INX H L0B57: MOV D,M L0B58: CALL ScreenAddr L0B5B: XCHG L0B5C: LXI D,BalloonLeftPic ;Picture with a blank column on the right L0B5F: CALL DrawBalloon L0B62: POP H L0B63: LXI D,$0006 ;Skip one balloon L0B66: DAD D L0B67: POP PSW L0B68: DCR A L0B69: JNZ L0B47 L0B6C: RET ;------------------------------------------------------------------------------ ; PlayerRow - HL = balloon address DE, moved to player 2's rows when PLAYER is 2. DE = P2_OFFSET. ;------------------------------------------------------------------------------ PlayerRow: L0B6D: XCHG L0B6E: LDA PLAYER L0B71: LXI D,P2_OFFSET L0B74: ANA A L0B75: RZ ;Player 1 L0B76: DAD D L0B77: RET ;------------------------------------------------------------------------------ ; DrawBalloon - Draw the 8-row balloon picture DE at screen address HL through the shifter. ; Overwrites two screen bytes per row. The blank column on the trailing side ; of each picture wipes the column the balloon has just left. ;------------------------------------------------------------------------------ DrawBalloon: L0B78: MVI B,$08 L0B7A: LDAX D L0B7B: INX D L0B7C: OUT OUT_SHIFT_DATA ;Picture byte, shifted L0B7E: IN INP_SHIFT L0B80: MOV M,A L0B81: INX H L0B82: XRA A ;Flush the shifter: the spill L0B83: OUT OUT_SHIFT_DATA L0B85: IN INP_SHIFT L0B87: MOV M,A L0B88: MOV A,B L0B89: LXI B,$001F ;To the next line: 32 - 1 L0B8C: DAD B L0B8D: MOV B,A L0B8E: DCR B L0B8F: JNZ L0B7A ;Next row L0B92: RET ;------------------------------------------------------------------------------ ; BalloonRightPic - Balloon as drawn in the rows that move right. ;------------------------------------------------------------------------------ BalloonRightPic: L0B93: .byte $38 ;...###.. L0B94: .byte $7C ;..#####. L0B95: .byte $FE ;.####### L0B96: .byte $BE ;.#####.# L0B97: .byte $9E ;.####..# L0B98: .byte $4C ;..##..#. L0B99: .byte $38 ;...###.. L0B9A: .byte $00 ;........ ;------------------------------------------------------------------------------ ; BalloonLeftPic - Balloon as drawn in the row that moves left. ;------------------------------------------------------------------------------ BalloonLeftPic: L0B9B: .byte $00 ;........ L0B9C: .byte $1C ;..###... L0B9D: .byte $3E ;.#####.. L0B9E: .byte $7F ;#######. L0B9F: .byte $5F ;#####.#. L0BA0: .byte $4F ;####..#. L0BA1: .byte $26 ;.##..#.. L0BA2: .byte $1C ;..###... L0BA3: .byte $00 ;unused ;------------------------------------------------------------------------------ ; ServeClown - Start a new jump when SERVE_REQUEST is set. ; One clown object becomes the rider, standing on the seesaw at Y $C4. The ; other becomes the flyer and starts on one of the four ledges, picked at ; random from ServeTable: it walks (slow object) toward the middle until ; TMR_SERVE_JUMP makes it jump off one second later. ;------------------------------------------------------------------------------ ServeClown: L0BA4: LXI H,SERVE_REQUEST L0BA7: MOV A,M ;Requested? L0BA8: ANA A L0BA9: RZ L0BAA: MVI M,$00 ;Once L0BAC: CALL Random L0BAF: ANI $03 ;1-4 L0BB1: INR A L0BB2: LXI H,ServeTable-6 ;Entry 1 is at ServeTable L0BB5: LXI B,$0006 ;6 bytes per entry L0BB8: DAD B L0BB9: DCR A L0BBA: JNZ L0BB8 L0BBD: PUSH H ;The ledge's entry L0BBE: LDA PLAYER ;Which player? (only swaps the two objects) L0BC1: ANA A L0BC2: LXI H,CLOWN_A L0BC5: LXI D,CLOWN_B L0BC8: JNZ L0BCC L0BCB: XCHG L0BCC: XCHG ;HL = rider object, DE = flyer object L0BCD: MVI M,$80 ;Rider: in use L0BCF: PUSH H L0BD0: DAD B ;-> CL_Y L0BD1: DCX H L0BD2: MVI M,$C4 ;Standing on the seesaw L0BD4: POP H L0BD5: SHLD RIDER_PTR L0BD8: XCHG L0BD9: DAD B ;HL -> past the flyer's first six bytes L0BDA: POP D L0BDB: LDAX D ;Copy the entry backwards: L0BDC: INX D L0BDD: DCX H L0BDE: MOV M,A ;Y, YVEL, X, XVEL, FRAME, STATE L0BDF: DCR C L0BE0: JNZ L0BDB L0BE3: SHLD FLYER_PTR L0BE6: MVI A,$01 ;Walk animation starts L0BE8: STA TMR_WALK L0BEB: STA SERVING ;No gravity or tumbling yet L0BEE: MVI A,$1E ;Jump off after 30 ticks L0BF0: STA TMR_SERVE_JUMP L0BF3: RET ;------------------------------------------------------------------------------ ; ServeTable - Flyer start values for the four ledges: CL_Y down to CL_STATE. ;------------------------------------------------------------------------------ ServeTable: L0BF4: .byte $68, $00, $00, $01, $09, $90 ;Y=$68 YVEL=0 X=$00 XVEL=1 FRAME=$09 STATE=$90: upper left ledge L0BFA: .byte $88, $00, $00, $01, $09, $90 ;Y=$88 YVEL=0 X=$00 XVEL=1 FRAME=$09 STATE=$90: lower left ledge L0C00: .byte $68, $00, $F0, $FF, $0C, $90 ;Y=$68 YVEL=0 X=$F0 XVEL=-1 FRAME=$0C STATE=$90: upper right ledge L0C06: .byte $88, $00, $F0, $FF, $0C, $90 ;Y=$88 YVEL=0 X=$F0 XVEL=-1 FRAME=$0C STATE=$90: lower right ledge L0C0C: .byte $00 ;unused ;------------------------------------------------------------------------------ ; FormatScores - In a game: write both scores and the jumps left into TEXT_BUF. ; Falls into DrawNextDigit. ;------------------------------------------------------------------------------ FormatScores: L0C0D: LDA GAME_ACTIVE L0C10: ANA A L0C11: RZ ;Attract mode: the script draws the scores L0C12: LXI H,TEXT_BUF L0C15: LXI B,P1_SCORE L0C18: CALL FormatScore ;Player 1 score: 5 characters L0C1B: LDAX B ;Jumps left L0C1C: INX B L0C1D: CALL NibbleToChar ;as a digit L0C20: MOV M,A L0C21: INX H L0C22: CALL FormatScore ;Player 2 score ;------------------------------------------------------------------------------ ; DrawNextDigit - In a game: draw the next character of TEXT_BUF at its place on the score line. ; One character per call (three calls per main loop pass). Six characters in a ; one-player game, eleven with two players. ;------------------------------------------------------------------------------ DrawNextDigit: L0C25: LDA GAME_ACTIVE L0C28: ANA A L0C29: RZ ;Attract mode L0C2A: LDA TWO_PLAYERS L0C2D: ANA A L0C2E: MVI B,$06 ;Player 1 score and jumps left L0C30: JZ L0C35 L0C33: MVI B,$0B ;Two players: the second score as well L0C35: LXI H,DIGIT_INDEX L0C38: MOV A,M L0C39: INR A L0C3A: CMP B ;Past the last one? L0C3B: JC L0C3F L0C3E: XRA A ;Start again L0C3F: MOV M,A L0C40: MOV C,A L0C41: MVI B,$00 L0C43: LXI H,ScoreLineAddrs ;Screen address of this character L0C46: DAD B L0C47: DAD B L0C48: MOV E,M L0C49: INX H L0C4A: MOV D,M L0C4B: LXI H,TEXT_BUF ;HL -> the character L0C4E: DAD B L0C4F: MVI A,$01 ;One character L0C51: JMP DrawString ;------------------------------------------------------------------------------ ; BcdToChars - Write the BCD byte at BC as two digit characters at HL. ;------------------------------------------------------------------------------ BcdToChars: L0C54: LDAX B L0C55: CALL HighNibbleToChar ;High digit L0C58: MOV M,A L0C59: INX H L0C5A: LDAX B L0C5B: INX B L0C5C: CALL NibbleToChar ;Low digit L0C5F: MOV M,A L0C60: INX H L0C61: RET ;------------------------------------------------------------------------------ ; FormatScore - Write the 2-byte BCD score at BC as 5 characters at HL. ; Four digits with leading zeros turned into blanks ('@'), then the fixed ; final '0': scores count tens of points. ;------------------------------------------------------------------------------ FormatScore: L0C62: MOV D,H ;DE = start of the text L0C63: MOV E,L L0C64: CALL BcdToChars L0C67: CALL BcdToChars L0C6A: XCHG ;From the start: L0C6B: CALL BlankZeros ;blank the leading zeros L0C6E: XCHG L0C6F: MVI M,$30 ;The units digit is always 0 L0C71: INX H L0C72: RET ;------------------------------------------------------------------------------ ; HighNibbleToChar - A = character for the high nibble of A. ;------------------------------------------------------------------------------ HighNibbleToChar: L0C73: RRC L0C74: RRC L0C75: RRC L0C76: RRC ;------------------------------------------------------------------------------ ; NibbleToChar - A = character '0'-'9' ('A'-'F') for the low nibble of A. ;------------------------------------------------------------------------------ NibbleToChar: L0C77: ANI $0F L0C79: ADI $90 ;The usual 8080 hex-to-ASCII trick L0C7B: DAA L0C7C: ACI $40 L0C7E: DAA L0C7F: RET ;------------------------------------------------------------------------------ ; BlankZeros - Replace '0' characters from HL by blanks, up to the first other character. ;------------------------------------------------------------------------------ BlankZeros: L0C80: MOV A,M L0C81: CPI $30 L0C83: RNZ ;Not a zero: done L0C84: MVI M,$40 ;'@' is the blank L0C86: INX H L0C87: JMP BlankZeros ;------------------------------------------------------------------------------ ; ScoreLineAddrs - Screen address for each character of TEXT_BUF. ;------------------------------------------------------------------------------ ScoreLineAddrs: L0C8A: .word $2598 ;player 1 score (col 24, line 12) L0C8C: .word $2599 ;player 1 score (col 25, line 12) L0C8E: .word $259A ;player 1 score (col 26, line 12) L0C90: .word $259B ;player 1 score (col 27, line 12) L0C92: .word $259C ;player 1 score (col 28, line 12) L0C94: .word $2590 ;jumps left (col 16, line 12) L0C96: .word $2583 ;player 2 score (col 3, line 12) L0C98: .word $2584 ;player 2 score (col 4, line 12) L0C9A: .word $2585 ;player 2 score (col 5, line 12) L0C9C: .word $2586 ;player 2 score (col 6, line 12) L0C9E: .word $2587 ;player 2 score (col 7, line 12) ;------------------------------------------------------------------------------ ; ReadStartButtons - Read the two start buttons (twice, for a stable reading). ;------------------------------------------------------------------------------ ReadStartButtons: L0CA0: IN INP_SWITCH L0CA2: MOV B,A L0CA3: IN INP_SWITCH L0CA5: CMP B ;The same both times? L0CA6: RNZ ;No: keep the old state L0CA7: CMA ;Active low L0CA8: ANI $20 ;b5: 1-player start L0CAA: STA START1_DOWN L0CAD: MOV A,B L0CAE: CMA L0CAF: ANI $10 ;b4: 2-player start L0CB1: STA START2_DOWN L0CB4: RET ;------------------------------------------------------------------------------ ; DrawPlayfieldIfOn - Redraw the floor and ledges when PLAYFIELD_ON. ;------------------------------------------------------------------------------ DrawPlayfieldIfOn: L0CB5: LDA PLAYFIELD_ON L0CB8: ANA A L0CB9: RZ ;------------------------------------------------------------------------------ ; DrawPlayfield - Draw the floor line and the four ledges. ;------------------------------------------------------------------------------ DrawPlayfield: L0CBA: LXI H,$3E80 ;Line 212, column 0 L0CBD: LXI B,$20FF ;B = 32 bytes, C = solid L0CC0: CALL FillRun ;The floor, full width L0CC3: LXI H,$3700 ;Line 152, left L0CC6: MVI B,$04 ;32 pixels L0CC8: CALL FillRun L0CCB: LXI H,$371C ;Line 152, right L0CCE: MVI B,$04 L0CD0: CALL FillRun L0CD3: LXI H,$3300 ;Line 120, left L0CD6: CALL FillRun3 ;24 pixels L0CD9: LXI H,$331D ;Line 120, right FillRun3: L0CDC: MVI B,$03 ;------------------------------------------------------------------------------ ; FillRun - Write C to B bytes from HL. ;------------------------------------------------------------------------------ FillRun: L0CDE: MOV M,C L0CDF: INX H L0CE0: DCR B L0CE1: JNZ FillRun L0CE4: RET ;------------------------------------------------------------------------------ ; Autopilot - Attract mode: put the seesaw under the falling clown. ; PADDLE_POS = flyer X - 4 when the right end is down, X - 24 when the left ; end is down, so that the flyer comes down on the raised end. If that is ; not within 0-$DF, the seesaw goes to the end of the floor on the flyer's ; half of the screen. ;------------------------------------------------------------------------------ Autopilot: L0CE5: LDA AUTOPILOT L0CE8: ANA A L0CE9: RZ ;Only in attract mode L0CEA: LDA TMR_HIT_LOCKOUT ;Just launched: leave the seesaw L0CED: ANA A L0CEE: RNZ L0CEF: LHLD FLYER_PTR L0CF2: MOV A,M L0CF3: ANA A L0CF4: RP ;Flyer not in use L0CF5: INX H ;HL -> CL_X L0CF6: INX H L0CF7: INX H L0CF8: MOV B,M ;B = X L0CF9: LDA SEESAW_STATE L0CFC: ANI $20 ;Which end is down? L0CFE: MVI A,$FC ;Right end: 4 left of the flyer L0D00: JNZ L0D05 L0D03: MVI A,$E8 ;Left end: 24 left of the flyer L0D05: ADD M L0D06: CPI $E0 ;Within 0-$DF? L0D08: JC L0D12 ;Yes L0D0B: INR B ;Flyer in the right half? L0D0C: MVI A,$D7 ;Yes: far right L0D0E: JM L0D12 L0D11: XRA A ;No: far left L0D12: STA PADDLE_POS L0D15: RET ;------------------------------------------------------------------------------ ; CheckRowsCleared - In a game: award the bonus when the player empties a balloon row. ; INP_DIP b4 off (each row): the first empty row among top, middle, bottom ; scores its RowBonusTable value and is refilled 5 seconds later. b4 on (all ; rows): nothing until all three are empty, then 2000 points and all three ; are refilled. Either way BONUS and the value are shown, the bonus tune ; plays and flyer and balloons freeze for 3 seconds. ;------------------------------------------------------------------------------ CheckRowsCleared: L0D16: LDA REFILL_PENDING ;A refill already on its way? L0D19: ANA A L0D1A: RNZ L0D1B: LDA PLAYER ;Which player's rows? L0D1E: ANA A L0D1F: LXI H,P1_ROW_TOP L0D22: LXI D,P2_OFFSET L0D25: JZ L0D29 L0D28: DAD D L0D29: IN INP_DIP ;Balloon resets switch L0D2B: ANI $10 L0D2D: JNZ CheckAllRowsCleared ;All rows L0D30: MVI C,$02 ;Three rows: C = 2, 1, 0 L0D32: PUSH H L0D33: MVI B,$0C ;12 balloons L0D35: MOV A,M L0D36: ANA A L0D37: JM L0D8E ;One left: try the next row L0D3A: INX H L0D3B: INX H L0D3C: INX H L0D3D: DCR B L0D3E: JNZ L0D35 L0D41: POP H ;Empty row L0D42: SHLD REFILL_ROW_PTR ;Remember which, for the refill L0D45: LXI H,RowBonusTable ;Bonus table: C = 2 is the top row L0D48: DAD B L0D49: DAD B L0D4A: DAD B L0D4B: MOV A,M ;Row's Y: marks the refill as pending L0D4C: INX H AwardRowBonus: L0D4D: STA REFILL_PENDING L0D50: MVI A,$96 ;Refill in 150 ticks (5 s) L0D52: STA TMR_REFILL L0D55: MVI A,$5A ;Freeze for 90 ticks (3 s) L0D57: STA TMR_FREEZE L0D5A: STA FREEZE_REQ L0D5D: PUSH H L0D5E: MOV B,M ;BC = points, high byte first L0D5F: INX H L0D60: MOV C,M L0D61: CALL AddScore ;Add them L0D64: POP B ;BC -> the points again L0D65: LXI H,BONUS_BUF L0D68: PUSH H L0D69: CALL FormatScore ;as 5 characters in BONUS_BUF L0D6C: LXI H,BonusTune ;Bonus tune L0D6F: SHLD TUNE_PTR L0D72: LXI H,TxtBonus ;"BONUS" in big letters L0D75: LXI D,$3486 ;Line 132, column 6 L0D78: MVI A,$05 L0D7A: CALL DrawBigString L0D7D: POP H L0D7E: LXI D,$388D ;The value on line 164, column 13 L0D81: IN INP_DIP L0D83: ANI $10 ;Each-row values have a leading blank: L0D85: JNZ L0D89 L0D88: DCX D ;one column left L0D89: MVI A,$05 L0D8B: JMP DrawString ;Draw the 5 characters L0D8E: POP H ;Next row of this player: 2 x 36 bytes on L0D8F: DAD D L0D90: DAD D L0D91: DCR C L0D92: JP L0D32 ;Three rows L0D95: RET CheckAllRowsCleared: L0D96: SHLD REFILL_ROW_PTR ;Refill starts at the top row L0D99: MVI C,$03 ;Three rows L0D9B: MVI B,$0C L0D9D: MOV A,M L0D9E: ANA A L0D9F: RM ;A balloon left: no bonus yet L0DA0: INX H L0DA1: INX H L0DA2: INX H L0DA3: DCR B L0DA4: JNZ L0D9D L0DA7: DAD D ;Skip the other player's row L0DA8: DCR C L0DA9: JNZ L0D9B L0DAC: LXI H,AllRowsBonus ;All three empty: 2000 points L0DAF: INR A ;A = 1: refill pending L0DB0: JMP AwardRowBonus ;------------------------------------------------------------------------------ ; AllRowsBonus - Points for emptying all three rows (BCD, high byte first; in tens). ;------------------------------------------------------------------------------ AllRowsBonus: L0DB3: .byte $02, $00 ;all rows cleared: 2000 points ;------------------------------------------------------------------------------ ; RowBonusTable - Bonus per row: balloon Y, points high, points low. ;------------------------------------------------------------------------------ RowBonusTable: L0DB5: .byte $4E, $00, $20 ;bottom row (Y $4E) cleared: 200 points L0DB8: .byte $38, $00, $50 ;middle row (Y $38) cleared: 500 points L0DBB: .byte $24, $01, $00 ;top row (Y $24) cleared: 1000 points L0DBE: .byte $00 ;unused ;------------------------------------------------------------------------------ ; BonusTune - Played with every bonus (row cleared, extra jump). ;------------------------------------------------------------------------------ BonusTune: L0DBF: .byte $85 ;tempo: 5 frames per beat L0DC0: .byte $01, $00 ;1 beat of note $00 (rest) L0DC2: .byte $01, $0C ;1 beat of note $0C L0DC4: .byte $02, $0F ;2 beats of note $0F L0DC6: .byte $01, $0C ;1 beat of note $0C L0DC8: .byte $01, $0D ;1 beat of note $0D L0DCA: .byte $02, $0F ;2 beats of note $0F L0DCC: .byte $01, $00 ;1 beat of note $00 (rest) L0DCE: .byte $01, $0C ;1 beat of note $0C L0DD0: .byte $02, $0F ;2 beats of note $0F L0DD2: .byte $01, $0C ;1 beat of note $0C L0DD4: .byte $01, $0D ;1 beat of note $0D L0DD6: .byte $03, $0F ;3 beats of note $0F L0DD8: .byte $00 ;end of tune ;------------------------------------------------------------------------------ ; GameOverTune - Played when the game ends. ;------------------------------------------------------------------------------ GameOverTune: L0DD9: .byte $85 ;tempo: 5 frames per beat L0DDA: .byte $02, $08 ;2 beats of note $08 L0DDC: .byte $02, $0D ;2 beats of note $0D L0DDE: .byte $02, $0F ;2 beats of note $0F L0DE0: .byte $02, $12 ;2 beats of note $12 L0DE2: .byte $08, $11 ;8 beats of note $11 L0DE4: .byte $02, $08 ;2 beats of note $08 L0DE6: .byte $02, $0D ;2 beats of note $0D L0DE8: .byte $02, $0F ;2 beats of note $0F L0DEA: .byte $01, $12 ;1 beat of note $12 L0DEC: .byte $01, $11 ;1 beat of note $11 L0DEE: .byte $01, $0F ;1 beat of note $0F L0DF0: .byte $07, $11 ;7 beats of note $11 L0DF2: .byte $00 ;end of tune L0DF3: .byte $00 ;unused ;============================================================================== ; SECTION 5 Game script and text ($0DF4-$117A) ; The program that MainLoop interprets. Commands (opcode, arguments): ; $00 WAIT run the game tasks until a timer moves the script on ; $02 TEXT n, text, screen DrawString ; $04 DELAY n TMR_SCRIPT = n ticks (30 Hz); its expiry steps past the next WAIT ; $06 TIMEOUT n, addr TMR_TIMEOUT = n seconds; its expiry jumps to addr ; $08 GOTO addr ; $0A SET value, addr store a byte ; $0C CLEAR n zero n x 32 bytes below $4000 (ClearRamTop) ; $0E SCORE score, screen draw a 2-byte BCD score as 5 characters ; $10 BIGTEXT n, text, screen DrawBigString ; $12 IFZ addr, target jump if the byte is 0 ; $14 IFNZ addr, target jump if the byte is not 0 ; $16 COINSTART if a coin is in: take it and jump by coinage (CoinageScripts) ; $18 ROW y, addr fill a balloon row ; $1A DECCOIN / $1C INCCOIN COINS - 1 / + 1 ; $1E TONE / $20 QUIET steady tone on / tone and sounds off ; In the text, '@' is the blank, 'Q' prints as Y and 'K' as a down arrow; the ; comments show the text as it appears. ;============================================================================== ;------------------------------------------------------------------------------ ; AttractScript - Entry after power-on and after a game: 2 seconds, then the title screen. ;------------------------------------------------------------------------------ AttractScript: L0DF4: .byte $0A, $00, GAME_ACTIVE ;SET GAME_ACTIVE = $00 L0DF8: .byte $02, $01, TxtZero, $90, $25 ;TEXT "0" at col 16, line 12 L0DFE: .byte $04, $3C ;DELAY 60 ticks L0E00: .byte $00 ;WAIT ;------------------------------------------------------------------------------ ; ScrTitle - GAME OVER and the high score for 7 seconds. ;------------------------------------------------------------------------------ ScrTitle: L0E01: .byte $0C, $FE ;CLEAR $2040-$3FFF L0E03: .byte $0A, $01, SCRIPT_HOLD ;SET SCRIPT_HOLD = $01 Only the timeout moves on from the WAIT below L0E07: .byte $06, $07, ScrDemo ;TIMEOUT 7 s -> ScrDemo L0E0B: .byte $02, $0A, TxtPlayerOneUp, $16, $24 ;TEXT "PLAYER ONE" at col 22, line 0 L0E11: .byte $02, $0A, TxtPlayerTwo, $00, $24 ;TEXT "PLAYER TWO" at col 0, line 0 L0E17: .byte $0E, P1_SCORE, $97, $25 ;SCORE P1_SCORE at col 23, line 12 L0E1C: .byte $0E, P2_SCORE, $83, $25 ;SCORE P2_SCORE at col 3, line 12 L0E21: .byte $10, $04, TxtGame, $08, $30 ;BIGTEXT "GAME" at col 8, line 96 L0E27: .byte $10, $04, TxtOver, $08, $35 ;BIGTEXT "OVER" at col 8, line 136 L0E2D: .byte $02, $0A, TxtHighScore, $0B, $3A ;TEXT "HIGH SCORE" at col 11, line 176 L0E33: .byte $0E, HI_SCORE, $0D, $3C ;SCORE HI_SCORE at col 13, line 192 L0E38: .byte $00 ;WAIT ;------------------------------------------------------------------------------ ; ScrDemo - Attract demo: one clown, autopilot. Restarts after 45 seconds or 1 second after a splat. ;------------------------------------------------------------------------------ ScrDemo: L0E39: .byte $20 ;QUIET L0E3A: .byte $16 ;COINSTART A coin starts a game L0E3B: .byte $0A, $00, TUNE_ON ;SET TUNE_ON = $00 L0E3F: .byte $0A, $00, SPEED_LEVEL ;SET SPEED_LEVEL = $00 L0E43: .byte $06, $2D, ScrDemo ;TIMEOUT 45 s -> ScrDemo L0E47: .byte $0C, $FE ;CLEAR $2040-$3FFF L0E49: .byte $02, $0A, TxtPlayerOneUp, $16, $24 ;TEXT "PLAYER ONE" at col 22, line 0 L0E4F: .byte $02, $0A, TxtPlayerTwo, $00, $24 ;TEXT "PLAYER TWO" at col 0, line 0 L0E55: .byte $0E, P1_SCORE, $97, $25 ;SCORE P1_SCORE at col 23, line 12 L0E5A: .byte $0E, P2_SCORE, $83, $25 ;SCORE P2_SCORE at col 3, line 12 L0E5F: .byte $02, $0A, TxtHighScore, $86, $3E ;TEXT "HIGH SCORE" at col 6, line 212 L0E65: .byte $0E, HI_SCORE, $80, $3E ;SCORE HI_SCORE at col 0, line 212 L0E6A: .byte $02, $0D, TxtInsertCoin, $93, $3E ;TEXT "v INSERT COIN" at col 19, line 212 Down arrow + INSERT COIN L0E70: .byte $18, $24, P1_ROW_TOP ;ROW P1_ROW_TOP Y=$24 L0E74: .byte $18, $38, P1_ROW_MID ;ROW P1_ROW_MID Y=$38 L0E78: .byte $18, $4E, P1_ROW_BOT ;ROW P1_ROW_BOT Y=$4E L0E7C: .byte $0A, $01, SERVE_REQUEST ;SET SERVE_REQUEST = $01 Serve a clown L0E80: .byte $0A, $A0, SEESAW_STATE ;SET SEESAW_STATE = $A0 L0E84: .byte $0A, $C0, ERASE_MODE ;SET ERASE_MODE = $C0 Erase by restoring the background L0E88: .byte $0A, $05, GRAVITY_PERIOD ;SET GRAVITY_PERIOD = $05 Gravity every 5 ticks L0E8C: .byte $0A, $01, PLAYFIELD_ON ;SET PLAYFIELD_ON = $01 L0E90: .byte $0A, $01, AUTOPILOT ;SET AUTOPILOT = $01 ScrDemoLoop: L0E94: .byte $20 ;QUIET L0E95: .byte $16 ;COINSTART L0E96: .byte $04, $05 ;DELAY 5 ticks L0E98: .byte $00 ;WAIT L0E99: .byte $08, ScrDemoLoop ;GOTO ScrDemoLoop ;------------------------------------------------------------------------------ ; ScrCoin1C1P - Coinage 0: one coin, one player. A second coin buys the two-player game. ;------------------------------------------------------------------------------ ScrCoin1C1P: L0E9C: .byte $0C, $FE ;CLEAR $2040-$3FFF L0E9E: .byte $02, $0D, TxtToStartGame, $09, $30 ;TEXT "TO START GAME" at col 9, line 96 L0EA4: .byte $02, $17, TxtPressOnePlayerButton, $04, $32 ;TEXT "PRESS ONE PLAYER BUTTON" at col 4, line 112 L0EAA: .byte $02, $02, TxtOr, $0F, $35 ;TEXT "OR" at col 15, line 136 L0EB0: .byte $02, $10, TxtDeposit2ndCoin, $08, $38 ;TEXT "DEPOSIT 2ND COIN" at col 8, line 160 L0EB6: .byte $02, $11, TxtFor2PlayerGame, $07, $3A ;TEXT "FOR 2 PLAYER GAME" at col 7, line 176 L0EBC: .byte $0A, $01, COINS_PER_GAME ;SET COINS_PER_GAME = $01 L0EC0: .byte $14, START1_DOWN, ScrNewGame ;IFNZ START1_DOWN GOTO ScrNewGame L0EC5: .byte $14, COINS, ScrSecondCoin ;IFNZ COINS GOTO ScrSecondCoin L0ECA: .byte $04, $05 ;DELAY 5 ticks L0ECC: .byte $00 ;WAIT L0ECD: .byte $08, L0EC0 ;GOTO L0EC0 ScrSecondCoin: L0ED0: .byte $0C, $FE ;CLEAR $2040-$3FFF L0ED2: .byte $02, $09, TxtPressTwo, $04, $30 ;TEXT "PRESS TWO" at col 4, line 96 L0ED8: .byte $02, $0D, TxtPlayerButton, $0E, $30 ;TEXT "PLAYER BUTTON" at col 14, line 96 L0EDE: .byte $02, $0D, TxtToStartGame, $09, $33 ;TEXT "TO START GAME" at col 9, line 120 L0EE4: .byte $0A, $02, COINS_PER_GAME ;SET COINS_PER_GAME = $02 L0EE8: .byte $14, START2_DOWN, ScrTwoPlayersPaid ;IFNZ START2_DOWN GOTO ScrTwoPlayersPaid L0EED: .byte $04, $05 ;DELAY 5 ticks L0EEF: .byte $00 ;WAIT L0EF0: .byte $08, L0EE8 ;GOTO L0EE8 ;------------------------------------------------------------------------------ ; ScrCoin1C2P - Coinage 1: one coin, one or two players. ;------------------------------------------------------------------------------ ScrCoin1C2P: L0EF3: .byte $0C, $FE ;CLEAR $2040-$3FFF L0EF5: .byte $0A, $01, COINS_PER_GAME ;SET COINS_PER_GAME = $01 ScrEitherButton: L0EF9: .byte $14, START1_DOWN, ScrNewGame ;IFNZ START1_DOWN GOTO ScrNewGame L0EFE: .byte $14, START2_DOWN, ScrTwoPlayers ;IFNZ START2_DOWN GOTO ScrTwoPlayers L0F03: .byte $04, $05 ;DELAY 5 ticks L0F05: .byte $00 ;WAIT L0F06: .byte $08, ScrEitherButton ;GOTO ScrEitherButton ;------------------------------------------------------------------------------ ; ScrCoin2C2P - Coinage 2: two coins, one or two players. Waits for the second coin. ;------------------------------------------------------------------------------ ScrCoin2C2P: L0F09: .byte $0C, $FE ;CLEAR $2040-$3FFF L0F0B: .byte $14, COINS, L0F16 ;IFNZ COINS GOTO L0F16 L0F10: .byte $04, $05 ;DELAY 5 ticks L0F12: .byte $00 ;WAIT L0F13: .byte $08, L0F0B ;GOTO L0F0B L0F16: .byte $1A ;DECCOIN L0F17: .byte $0A, $02, COINS_PER_GAME ;SET COINS_PER_GAME = $02 L0F1B: .byte $0C, $FE ;CLEAR $2040-$3FFF L0F1D: .byte $08, ScrEitherButton ;GOTO ScrEitherButton ;------------------------------------------------------------------------------ ; ScrCoin2C1P - Coinage 3: two coins per player. ; After the second coin the 1-player button starts a game. A third coin is ; taken while waiting, and a fourth allows the 2-player button; coins taken ; but not needed are given back when the 1-player button is pressed. ;------------------------------------------------------------------------------ ScrCoin2C1P: L0F20: .byte $0C, $FE ;CLEAR $2040-$3FFF L0F22: .byte $14, COINS, L0F2D ;IFNZ COINS GOTO L0F2D L0F27: .byte $04, $05 ;DELAY 5 ticks L0F29: .byte $00 ;WAIT L0F2A: .byte $08, L0F22 ;GOTO L0F22 L0F2D: .byte $0C, $FE ;CLEAR $2040-$3FFF L0F2F: .byte $1A ;DECCOIN L0F30: .byte $0A, $02, COINS_PER_GAME ;SET COINS_PER_GAME = $02 L0F34: .byte $14, START1_DOWN, ScrNewGame ;IFNZ START1_DOWN GOTO ScrNewGame L0F39: .byte $14, COINS, L0F44 ;IFNZ COINS GOTO L0F44 L0F3E: .byte $04, $05 ;DELAY 5 ticks L0F40: .byte $00 ;WAIT L0F41: .byte $08, L0F34 ;GOTO L0F34 L0F44: .byte $1A ;DECCOIN L0F45: .byte $14, COINS, L0F55 ;IFNZ COINS GOTO L0F55 L0F4A: .byte $14, START1_DOWN, L0F66 ;IFNZ START1_DOWN GOTO L0F66 L0F4F: .byte $04, $05 ;DELAY 5 ticks L0F51: .byte $00 ;WAIT L0F52: .byte $08, L0F45 ;GOTO L0F45 L0F55: .byte $1A ;DECCOIN L0F56: .byte $14, START2_DOWN, L0F77 ;IFNZ START2_DOWN GOTO L0F77 L0F5B: .byte $14, START1_DOWN, L0F6E ;IFNZ START1_DOWN GOTO L0F6E L0F60: .byte $04, $05 ;DELAY 5 ticks L0F62: .byte $00 ;WAIT L0F63: .byte $08, L0F56 ;GOTO L0F56 L0F66: .byte $0A, $01, COINS_PER_GAME ;SET COINS_PER_GAME = $01 L0F6A: .byte $1C ;INCCOIN L0F6B: .byte $08, ScrNewGame ;GOTO ScrNewGame L0F6E: .byte $0A, $02, COINS_PER_GAME ;SET COINS_PER_GAME = $02 L0F72: .byte $1C ;INCCOIN L0F73: .byte $1C ;INCCOIN L0F74: .byte $08, ScrNewGame ;GOTO ScrNewGame L0F77: .byte $0A, $04, COINS_PER_GAME ;SET COINS_PER_GAME = $04 L0F7B: .byte $08, ScrTwoPlayers ;GOTO ScrTwoPlayers ScrTwoPlayersPaid: L0F7E: .byte $1A ;DECCOIN ScrTwoPlayers: L0F7F: .byte $0A, $01, TWO_PLAYERS ;SET TWO_PLAYERS = $01 ;------------------------------------------------------------------------------ ; ScrNewGame - Start of a game: fill all six balloon rows, zero the scores. ;------------------------------------------------------------------------------ ScrNewGame: L0F83: .byte $18, $24, P1_ROW_TOP ;ROW P1_ROW_TOP Y=$24 L0F87: .byte $18, $38, P1_ROW_MID ;ROW P1_ROW_MID Y=$38 L0F8B: .byte $18, $4E, P1_ROW_BOT ;ROW P1_ROW_BOT Y=$4E L0F8F: .byte $18, $24, P2_ROW_TOP ;ROW P2_ROW_TOP Y=$24 L0F93: .byte $18, $38, P2_ROW_MID ;ROW P2_ROW_MID Y=$38 L0F97: .byte $18, $4E, P2_ROW_BOT ;ROW P2_ROW_BOT Y=$4E L0F9B: .byte $0A, $00, P1_SCORE ;SET P1_SCORE = $00 L0F9F: .byte $0A, $00, <[P1_SCORE+1], >[P1_SCORE+1] ;SET P1_SCORE+1 = $00 L0FA3: .byte $0A, $00, P2_SCORE ;SET P2_SCORE = $00 L0FA7: .byte $0A, $00, <[P2_SCORE+1], >[P2_SCORE+1] ;SET P2_SCORE+1 = $00 L0FAB: .byte $0A, $01, GAME_ACTIVE ;SET GAME_ACTIVE = $01 L0FAF: .byte $0A, $A0, SEESAW_STATE ;SET SEESAW_STATE = $A0 ;------------------------------------------------------------------------------ ; ScrTurn - Start of every jump: clear the screen and clown objects, announce the player. ; The CLEAR keeps everything below $2180 (balloon rows, flags) and brings in ; PLAYER and JUMPS_LEFT for this turn. An extra jump shows SAME PLAYER / ; JUMPS AGAIN instead of GET READY. The down arrow marks the side of the ; player who is up: column 31 for player 1, column 0 for player 2. ;------------------------------------------------------------------------------ ScrTurn: L0FB3: .byte $0C, $F4 ;CLEAR $2180-$3FFF L0FB5: .byte $0A, $01, PADDLE_ENABLE ;SET PADDLE_ENABLE = $01 L0FB9: .byte $0A, $01, PLAYFIELD_ON ;SET PLAYFIELD_ON = $01 L0FBD: .byte $0A, $00, TUNE_ON ;SET TUNE_ON = $00 L0FC1: .byte $02, $0A, TxtPlayerOneUp, $16, $24 ;TEXT "PLAYER ONE" at col 22, line 0 L0FC7: .byte $02, $05, TxtJumpsAgain, $0E, $24 ;TEXT "JUMPS" at col 14, line 0 L0FCD: .byte $12, TWO_PLAYERS, L0FD8 ;IFZ TWO_PLAYERS GOTO L0FD8 L0FD2: .byte $02, $0A, TxtPlayerTwo, $00, $24 ;TEXT "PLAYER TWO" at col 0, line 0 L0FD8: .byte $12, JUMPS_AGAIN, ScrGetReady ;IFZ JUMPS_AGAIN GOTO ScrGetReady L0FDD: .byte $1E ;TONE L0FDE: .byte $10, $04, TxtSame, $08, $32 ;BIGTEXT "SAME" at col 8, line 112 L0FE4: .byte $10, $06, TxtPlayerJumpsAgain, $04, $36 ;BIGTEXT "PLAYER" at col 4, line 144 L0FEA: .byte $02, $01, TxtInsertCoin, $9F, $3E ;TEXT "v" at col 31, line 212 L0FF0: .byte $12, PLAYER, ScrReadyWait ;IFZ PLAYER GOTO ScrReadyWait L0FF5: .byte $02, $01, TxtBlanks, $9F, $3E ;TEXT " " at col 31, line 212 L0FFB: .byte $02, $01, TxtInsertCoin, $80, $3E ;TEXT "v" at col 0, line 212 L1001: .byte $08, ScrGo ;GOTO ScrGo ScrGetReady: L1004: .byte $02, $09, TxtGetReady, $0B, $32 ;TEXT "GET READY" at col 11, line 112 L100A: .byte $02, $01, TxtInsertCoin, $9F, $3E ;TEXT "v" at col 31, line 212 L1010: .byte $12, TWO_PLAYERS, ScrReadyWait ;IFZ TWO_PLAYERS GOTO ScrReadyWait L1015: .byte $02, $0D, TxtPlayerOneUp, $0A, $32 ;TEXT "PLAYER ONE UP" at col 10, line 112 L101B: .byte $12, PLAYER, ScrReadyWait ;IFZ PLAYER GOTO ScrReadyWait L1020: .byte $02, $01, TxtBlanks, $9F, $3E ;TEXT " " at col 31, line 212 L1026: .byte $02, $03, TxtTwo, $11, $32 ;TEXT "TWO" at col 17, line 112 L102C: .byte $02, $01, TxtInsertCoin, $80, $3E ;TEXT "v" at col 0, line 212 ScrReadyWait: L1032: .byte $06, $03, ScrGo ;TIMEOUT 3 s -> ScrGo L1036: .byte $12, JUMPS_AGAIN, L1041 ;IFZ JUMPS_AGAIN GOTO L1041 L103B: .byte $02, $0B, TxtJumpsAgain, $8A, $3E ;TEXT "JUMPS AGAIN" at col 10, line 212 L1041: .byte $04, $07 ;DELAY 7 ticks L1043: .byte $00 ;WAIT L1044: .byte $02, $0B, TxtBlanks, $8A, $3E ;TEXT " " at col 10, line 212 L104A: .byte $04, $07 ;DELAY 7 ticks L104C: .byte $00 ;WAIT L104D: .byte $08, L1036 ;GOTO L1036 ;------------------------------------------------------------------------------ ; ScrGo - GO: serve the clown, clear the messages, then wait for the jump to end. ;------------------------------------------------------------------------------ ScrGo: L1050: .byte $14, JUMPS_AGAIN, L105B ;IFNZ JUMPS_AGAIN GOTO L105B L1055: .byte $10, $02, TxtGo, $0C, $36 ;BIGTEXT "GO" at col 12, line 144 L105B: .byte $0A, $01, SERVE_REQUEST ;SET SERVE_REQUEST = $01 Serve a clown L105F: .byte $0A, $C0, ERASE_MODE ;SET ERASE_MODE = $C0 L1063: .byte $0A, $04, GRAVITY_PERIOD ;SET GRAVITY_PERIOD = $04 Gravity every 4 ticks L1067: .byte $0A, $00, SPEED_LEVEL ;SET SPEED_LEVEL = $00 L106B: .byte $04, $0F ;DELAY 15 ticks L106D: .byte $00 ;WAIT L106E: .byte $02, $11, TxtBlanks, $08, $32 ;TEXT " " at col 8, line 112 L1074: .byte $10, $04, TxtBlanks, $04, $36 ;BIGTEXT " " at col 4, line 144 L107A: .byte $12, JUMPS_AGAIN, L1091 ;IFZ JUMPS_AGAIN GOTO L1091 L107F: .byte $02, $0B, TxtBlanks, $8A, $3E ;TEXT " " at col 10, line 212 L1085: .byte $10, $06, TxtBlanks, $04, $36 ;BIGTEXT " " at col 4, line 144 L108B: .byte $10, $06, TxtBlanks, $08, $32 ;BIGTEXT " " at col 8, line 112 L1091: .byte $12, BONUS_GAME, L109C ;IFZ BONUS_GAME GOTO L109C L1096: .byte $02, $0F, TxtAdditionalGame, $88, $3E ;TEXT "ADDITIONAL GAME" at col 8, line 212 L109C: .byte $0A, $00, JUMPS_AGAIN ;SET JUMPS_AGAIN = $00 L10A0: .byte $0A, $01, TUNE_ON ;SET TUNE_ON = $01 ScrJump: L10A4: .byte $00 ;WAIT The jump is played here; SplatDone starts TMR_SCRIPT to move on L10A5: .byte $04, $3C ;DELAY 60 ticks L10A7: .byte $00 ;WAIT L10A8: .byte $08, ScrTurn ;GOTO ScrTurn Next jump (or AttractScript when GameOver has changed SCRIPT_PTR) ;------------------------------------------------------------------------------ ; CoinageScripts - Script entered by COINSTART for each coinage setting (INP_DIP b0-b1). ;------------------------------------------------------------------------------ CoinageScripts: L10AB: .word ScrCoin1C1P ;coinage 0: 1 coin 1 player L10AD: .word ScrCoin1C2P ;coinage 1: 1 coin 2 players L10AF: .word ScrCoin2C2P ;coinage 2: 2 coins 2 players L10B1: .word ScrCoin2C1P ;coinage 3: 2 coins 1 player ;------------------------------------------------------------------------------ ; TxtBlanks - Text. 17 blanks, used to erase messages. ;------------------------------------------------------------------------------ TxtBlanks: L10B3: .byte $40, $40, $40, $40, $40, $40, $40, $40 ;" " L10BB: .byte $40, $40, $40, $40, $40, $40, $40, $40 ;" " L10C3: .byte $40 ;" " TxtPlayerOneUp: L10C4: .byte $50, $4C, $41, $51, $45, $52, $40, $4F ;"PLAYER O" L10CC: .byte $4E, $45, $40, $55, $50 ;"NE UP" TxtPlayerTwo: L10D1: .byte $50, $4C, $41, $51, $45, $52, $40 ;"PLAYER " TxtTwo: L10D8: .byte $54, $57, $4F ;"TWO" TxtPlayerJumpsAgain: L10DB: .byte $50, $4C, $41, $51, $45, $52, $40 ;"PLAYER " TxtJumpsAgain: L10E2: .byte $4A, $55, $4D, $50, $53, $40, $41, $47 ;"JUMPS AG" L10EA: .byte $41, $49, $4E ;"AIN" TxtAdditionalGame: L10ED: .byte $41, $44, $44, $49, $54, $49, $4F, $4E ;"ADDITION" L10F5: .byte $41, $4C, $40 ;"AL " TxtGame: L10F8: .byte $47, $41, $4D, $45 ;"GAME" TxtOver: L10FC: .byte $4F, $56, $45, $52 ;"OVER" TxtHighScore: L1100: .byte $48, $49, $47, $48, $40, $53, $43, $4F ;"HIGH SCO" L1108: .byte $52, $45 ;"RE" TxtZero: L110A: .byte $30 ;"0" TxtSame: L110B: .byte $53, $41, $4D, $45 ;"SAME" TxtGo: L110F: .byte $47, $4F ;"GO" TxtGetReady: L1111: .byte $47, $45, $54, $40, $52, $45, $41, $44 ;"GET READ" L1119: .byte $51 ;"Y" TxtBonus: L111A: .byte $42, $4F, $4E, $55, $53 ;"BONUS" TxtInsertCoin: L111F: .byte $4B, $40, $49, $4E, $53, $45, $52, $54 ;"v INSERT" L1127: .byte $40, $43, $4F, $49, $4E ;" COIN" TxtToStartGame: L112C: .byte $54, $4F, $40, $53, $54, $41, $52, $54 ;"TO START" L1134: .byte $40, $47, $41, $4D, $45 ;" GAME" TxtPressOnePlayerButton: L1139: .byte $50, $52, $45, $53, $53, $40, $4F, $4E ;"PRESS ON" L1141: .byte $45, $40 ;"E " TxtPlayerButton: L1143: .byte $50, $4C, $41, $51, $45, $52, $40, $42 ;"PLAYER B" L114B: .byte $55, $54, $54, $4F, $4E ;"UTTON" TxtDeposit2ndCoin: L1150: .byte $44, $45, $50, $4F, $53, $49, $54, $40 ;"DEPOSIT " L1158: .byte $32, $4E, $44, $40, $43, $4F, $49, $4E ;"2ND COIN" TxtFor2PlayerGame: L1160: .byte $46 ;"F" TxtOr: L1161: .byte $4F, $52, $40, $32, $40, $50, $4C, $41 ;"OR 2 PLA" L1169: .byte $51, $45, $52, $40, $47, $41, $4D, $45 ;"YER GAME" TxtPressTwo: L1171: .byte $50, $52, $45, $53, $53, $40, $54, $57 ;"PRESS TW" L1179: .byte $4F ;"O" L117A: .byte $00 ;unused ;============================================================================== ; SECTION 6 Timer events ($117B-$1348) ; The interrupt counts the timers down (TickTimers) and posts expiries as bits; ; the main loop picks the bits up here and calls one routine per timer. ;============================================================================== ;------------------------------------------------------------------------------ ; CheckTimeout - If TMR_TIMEOUT has run out, send the script to TIMEOUT_PTR. ;------------------------------------------------------------------------------ CheckTimeout: L117B: LXI H,EVT_TIMEOUT L117E: MOV A,M ;Event bits from the interrupt L117F: ANA A L1180: RZ ;None L1181: MVI M,$00 ;Taken L1183: RAR ;b0: the timeout L1184: PUSH PSW L1185: CC ScriptTimeout ;Jump the script L1188: POP PSW L1189: RET ;------------------------------------------------------------------------------ ; ScriptTimeout - SCRIPT_PTR = TIMEOUT_PTR, unless TIMEOUT_HOLD. ;------------------------------------------------------------------------------ ScriptTimeout: L118A: LDA TIMEOUT_HOLD ;A coin was taken: the timeout is off L118D: ANA A L118E: RNZ L118F: LHLD TIMEOUT_PTR L1192: SHLD SCRIPT_PTR L1195: RET ;------------------------------------------------------------------------------ ; RunTimerEvents - Call the handler of every 30 Hz timer that has expired. ;------------------------------------------------------------------------------ RunTimerEvents: L1196: LXI H,EVT_TIMERS L1199: MOV A,M ;Event bits from the interrupt L119A: ANA A L119B: RZ ;None L119C: MVI M,$00 ;Taken L119E: RAR ;b0: TMR_REFILL L119F: PUSH PSW L11A0: CC RefillRows L11A3: POP PSW L11A4: RAR ;b1: TMR_HIT_LOCKOUT has no handler L11A5: RAR ;b2: TMR_SPLAT L11A6: PUSH PSW L11A7: CC SplatStep L11AA: POP PSW L11AB: RAR ;b3: TMR_GRAVITY L11AC: PUSH PSW L11AD: CC GravityTick L11B0: POP PSW L11B1: RAR ;b4: TMR_SERVE_JUMP L11B2: PUSH PSW L11B3: CC ServeJump L11B6: POP PSW L11B7: RAR ;b5: TMR_WALK L11B8: PUSH PSW L11B9: CC WalkStep L11BC: POP PSW L11BD: RAR ;b6: TMR_SOUND_OFF L11BE: PUSH PSW L11BF: CC SoundOff L11C2: POP PSW L11C3: RAR ;b7: TMR_SCRIPT L11C4: PUSH PSW L11C5: CC ScriptTimerDone L11C8: POP PSW L11C9: RET ;------------------------------------------------------------------------------ ; SplatStep - TMR_SPLAT: next of the three splat pictures, then SplatDone. ;------------------------------------------------------------------------------ SplatStep: L11CA: LXI H,SPLAT_CTR L11CD: DCR M ;Pictures left L11CE: JZ SplatDone ;None: the jump is over L11D1: MVI A,$02 ;Next picture in 2 ticks L11D3: STA TMR_SPLAT L11D6: LHLD FLYER_PTR L11D9: INX H ;CL_FRAME L11DA: INR M ;$0F -> $10 -> $11: the clown sinks into the floor L11DB: RET ;------------------------------------------------------------------------------ ; SplatDone - The jump is over: next turn, next player or game over. ; The flyer is parked below the floor. Attract mode: restart the demo in a ; second. In a game: an extra jump (JUMPS_AGAIN) costs nothing; with two ; players the turn passes to player 2 first and a jump is used only after ; player 2's turn; when the last jump is used the game is over. ;------------------------------------------------------------------------------ SplatDone: L11DC: LHLD FLYER_PTR L11DF: INX H ;-> CL_XVEL L11E0: INX H L11E1: XRA A L11E2: MOV M,A ;Stop L11E3: INX H L11E4: INX H L11E5: MOV M,A ;CL_YVEL L11E6: INX H L11E7: MVI M,$DC ;CL_Y: under the floor line L11E9: LDA GAME_ACTIVE ;Game on? L11EC: ANA A L11ED: JZ DemoOver ;No: attract demo L11F0: LDA JUMPS_AGAIN ;Extra jump earned? L11F3: ANA A L11F4: JNZ NextTurn ;Yes: same player, same jumps L11F7: LDA TWO_PLAYERS ;Two players? L11FA: ANA A L11FB: JZ L1209 ;No L11FE: LDA PLAYER ;Other player L1201: XRI $FF L1203: STA NEXT_PLAYER ;next L1206: JNZ NextTurn ;Player 2 is up now: nothing used yet L1209: LDA JUMPS_LEFT ;Both have jumped (or one player): L120C: DCR A ;one jump used L120D: JZ GameOver ;That was the last L1210: STA NEXT_JUMPS_LEFT ;Jumps left for the next turn NextTurn: L1213: MVI A,$01 ;TMR_SCRIPT = 1: the script leaves ScrJump L1215: STA TMR_SCRIPT L1218: RET ;------------------------------------------------------------------------------ ; GameOver - Back to the attract script; play the tune; update the high score. ;------------------------------------------------------------------------------ GameOver: L1219: LDA BONUS_GAME ;Remember whether this game won a bonus game L121C: STA PREV_BONUS_GAME L121F: LXI H,AttractScript ;Script: attract mode L1222: SHLD SCRIPT_PTR L1225: LXI H,GameOverTune ;Game over tune L1228: SHLD TUNE_PTR L122B: LXI D,P1_SCORE ;Player 1 score L122E: LXI H,HI_SCORE ;against the high score L1231: CALL CheckHighScore L1234: INX D ;Player 2 score: falls into CheckHighScore L1235: INX D L1236: INX D ;------------------------------------------------------------------------------ ; CheckHighScore - If the 2-byte BCD score at DE beats the one at HL, copy it there. ;------------------------------------------------------------------------------ CheckHighScore: L1237: LDAX D ;High bytes L1238: CMP M L1239: RC ;Lower L123A: JNZ CopyScore ;Higher: new high score L123D: INX D ;Equal: low bytes L123E: LDAX D L123F: DCX D L1240: INX H L1241: CMP M L1242: DCX H L1243: RC ;Lower CopyScore: L1244: LDAX D L1245: INX D L1246: MOV M,A L1247: INX H L1248: LDAX D L1249: DCX D L124A: MOV M,A L124B: DCX H L124C: RET ;------------------------------------------------------------------------------ ; DemoOver - Attract mode splat: restart the demo one second from now. ;------------------------------------------------------------------------------ DemoOver: L124D: MVI A,$01 L124F: STA TMR_TIMEOUT ;TMR_TIMEOUT = 1 s (TIMEOUT_PTR is ScrDemo) L1252: STA SCRIPT_HOLD ;Keep the demo loop's DELAY from moving the script L1255: RET ;------------------------------------------------------------------------------ ; GravityTick - TMR_GRAVITY: flyer YVEL + 1; restart the timer from GRAVITY_PERIOD. ; No pull while the clown walks on its ledge or during a freeze. ;------------------------------------------------------------------------------ GravityTick: L1256: LDA SERVING ;Still on the ledge? L1259: ANA A L125A: JNZ RestartGravity L125D: LDA FREEZE_REQ ;Frozen? L1260: ANA A L1261: JNZ RestartGravity L1264: LHLD FLYER_PTR L1267: MOV A,M ;Splatted: leave it (the timer is not restarted) L1268: ANI $08 L126A: RNZ L126B: LXI D,CL_YVEL L126E: DAD D L126F: INR M ;One more pixel per update downward RestartGravity: L1270: LDA GRAVITY_PERIOD L1273: STA TMR_GRAVITY L1276: RET ;------------------------------------------------------------------------------ ; ServeJump - TMR_SERVE_JUMP: the served clown jumps off its ledge. ;------------------------------------------------------------------------------ ServeJump: L1277: LHLD FLYER_PTR L127A: MOV A,M L127B: ANI $EF ;No longer slow L127D: MOV M,A L127E: INX H L127F: MVI A,$01 ;Picture 1: tumbling L1281: MOV M,A L1282: STA TMR_GRAVITY ;Gravity starts on the next tick L1285: INX H L1286: INX H L1287: INX H L1288: MVI M,$FE ;YVEL: 2 up L128A: XRA A L128B: STA SERVING ;Serve is over L128E: RET ;------------------------------------------------------------------------------ ; WalkStep - TMR_WALK: every 3 ticks, step the walking clown's picture +1 +1 -1 -1. ;------------------------------------------------------------------------------ WalkStep: L128F: LDA SERVING ;Still walking? L1292: ANA A L1293: RZ L1294: MVI A,$03 ;Again in 3 ticks L1296: STA TMR_WALK L1299: LHLD FLYER_PTR L129C: LXI D,WALK_PHASE L129F: LDAX D L12A0: INR A L12A1: CPI $04 ;Phase 0-3 L12A3: JC L12A7 L12A6: XRA A L12A7: STAX D L12A8: MVI A,$01 ;Phases 1, 2: next picture L12AA: JPO L12AF ;(parity of the compare above) L12AD: MVI A,$FF ;Phases 3, 0: previous picture L12AF: INX H ;CL_FRAME L12B0: ADD M L12B1: MOV M,A L12B2: RET ;------------------------------------------------------------------------------ ; ScriptTimerDone - TMR_SCRIPT: step the script past the WAIT it is on, unless SCRIPT_HOLD. ;------------------------------------------------------------------------------ ScriptTimerDone: L12B3: LDA SCRIPT_HOLD L12B6: ANA A L12B7: RNZ L12B8: LHLD SCRIPT_PTR L12BB: INX H L12BC: SHLD SCRIPT_PTR L12BF: RET ;------------------------------------------------------------------------------ ; SoundOff - TMR_SOUND_OFF: end the pop / hit / miss sound, leave the board enabled. ;------------------------------------------------------------------------------ SoundOff: L12C0: MVI A,$08 L12C2: OUT OUT_SOUND L12C4: RET ;------------------------------------------------------------------------------ ; RunTimerEvents2 - Call the handlers of the second timer group. ;------------------------------------------------------------------------------ RunTimerEvents2: L12C5: LXI H,EVT_TIMERS2 L12C8: MOV A,M ;Event bits from the interrupt L12C9: ANA A L12CA: RZ L12CB: MVI M,$00 L12CD: RAR ;b0: TMR_FREEZE L12CE: PUSH PSW L12CF: CC EndFreeze L12D2: POP PSW L12D3: RAR ;b1: TMR_TUMBLE has no handler L12D4: RAR ;b2: TMR_COIN_CTR L12D5: PUSH PSW L12D6: CC CoinCounterOff L12D9: POP PSW L12DA: RET ;------------------------------------------------------------------------------ ; RefillRows - TMR_REFILL: put back the balloons of the cleared row(s). ;------------------------------------------------------------------------------ RefillRows: L12DB: LHLD REFILL_ROW_PTR ;The row, or the player's first row L12DE: IN INP_DIP ;Balloon resets switch L12E0: ANI $10 L12E2: JZ L1303 ;Each row L12E5: XRA A ;All rows: nothing pending any more L12E6: STA REFILL_PENDING L12E9: LXI D,P2_OFFSET L12EC: MVI B,$24 ;Top row L12EE: CALL FillBalloonRow L12F1: LXI D,P2_OFFSET L12F4: DAD D ;Skip the other player's row L12F5: MVI B,$38 ;Middle row L12F7: CALL FillBalloonRow L12FA: LXI D,P2_OFFSET L12FD: DAD D L12FE: MVI B,$4E ;Bottom row L1300: JMP FillBalloonRow L1303: LXI D,REFILL_PENDING ;Each row: REFILL_PENDING holds the row's Y L1306: LDAX D L1307: MOV B,A L1308: XRA A L1309: STAX D ;Nothing pending any more L130A: JMP FillBalloonRow ;------------------------------------------------------------------------------ ; EndFreeze - TMR_FREEZE: let flyer and balloons move again and erase the BONUS message. ; A flyer that is up in the balloon rows (Y below $60) is stopped dead so that ; it drops straight down. ;------------------------------------------------------------------------------ EndFreeze: L130D: LDA GAME_ACTIVE L1310: ANA A L1311: RZ ;Attract mode: nothing was frozen L1312: XRA A L1313: STA FREEZE_REQ L1316: STA FREEZE L1319: LHLD FLYER_PTR L131C: LXI D,CL_Y L131F: DAD D L1320: MOV A,M ;Flyer Y L1321: CPI $60 ;Among the balloons? L1323: JNC L132B ;No L1326: DCX H L1327: MOV M,D ;YVEL = 0 L1328: DCX H L1329: DCX H L132A: MOV M,D ;XVEL = 0 L132B: LXI H,TxtBlanks ;Blanks L132E: PUSH H L132F: LXI D,$3486 ;over the big BONUS L1332: MVI A,$05 L1334: CALL DrawBigString L1337: POP H L1338: LXI D,$388D ;and over the value L133B: MVI A,$05 L133D: JMP DrawString ;------------------------------------------------------------------------------ ; CoinCounterOff - TMR_COIN_CTR: end the coin counter pulse. ;------------------------------------------------------------------------------ CoinCounterOff: L1340: LXI H,OUT3_SHADOW L1343: MOV A,M L1344: ANI $FE L1346: MOV M,A L1347: RET L1348: .byte $00 ;unused ;============================================================================== ; SECTION 7 Switch test and RAM clear ($1349-$1412) ;============================================================================== ;------------------------------------------------------------------------------ ; SwitchTest - Switch test, entered from the RAM test when the coin switch is held. ; Shows COIN ON / OFF (and drives the coin counter while the switch is ; down), PLAYER 1 ON / OFF and PLAYER 2 ON / OFF for the start buttons, with ; the floor, the ledges and the seesaw following the paddle. Pressing a start ; button selects that player's paddle. Never leaves: only a reset ends it. ;------------------------------------------------------------------------------ SwitchTest: L1349: XRA A ;A = 0: clear all RAM L134A: CALL ClearRamTop L134D: EI ;The interrupts draw the seesaw L134E: OUT OUT_WATCHDOG L1350: CALL DrawPlayfield L1353: MVI A,$80 ;Seesaw on screen L1355: STA SEESAW_STATE L1358: LXI H,TxtCoin ;"COIN" L135B: LXI D,$3000 ;Line 96 L135E: MVI A,$04 ;PADDLE_ENABLE: any non-zero value L1360: STA PADDLE_ENABLE L1363: CALL DrawString ;4 characters; HL moves on to "OFF" L1366: INX D ;One column of space L1367: IN INP_SWITCH ;Coin switch, active low L1369: ANI $40 L136B: JNZ L1373 ;Up: "OFF", coin counter off ($40 has b0 clear) L136E: LXI H,TxtOn ;Down: "ON " L1371: MVI A,$01 ;and coin counter on L1373: STA OUT3_SHADOW L1376: MVI A,$03 ;3 characters L1378: CALL DrawString L137B: LXI D,$3400 ;Line 128 L137E: CALL DrawPlayerWord ;"PLAYER", A = 1 L1381: CALL DrawCharReadSwitches ;"1"; A = the switches L1384: ANI $20 ;1-player start down? L1386: JNZ L138E L1389: MVI A,$00 ;Yes: seesaw follows paddle 1 (flags are kept for DrawOnOff) L138B: STA PLAYER L138E: CALL DrawOnOff L1391: LXI D,$3800 ;Line 160 L1394: CALL DrawPlayerWord ;"PLAYER" L1397: CALL DrawNextChar ;"2" L139A: ANI $10 ;2-player start down? L139C: JNZ L13A4 L139F: MVI A,$FF ;Yes: seesaw follows paddle 2 L13A1: STA PLAYER L13A4: CALL DrawOnOff L13A7: LXI H,$0400 ;Short delay L13AA: DCX H L13AB: MOV A,H L13AC: ORA L L13AD: JNZ L13AA L13B0: JMP L134D ;------------------------------------------------------------------------------ ; DrawPlayerWord - Draw "PLAYER" at DE and leave a blank column; returns A = 1. ;------------------------------------------------------------------------------ DrawPlayerWord: L13B3: LXI H,TxtPlayer L13B6: MVI A,$06 L13B8: CALL DrawString L13BB: INX D L13BC: INR A L13BD: RET ;------------------------------------------------------------------------------ ; DrawNextChar - Skip one character of text, then as DrawCharReadSwitches. ;------------------------------------------------------------------------------ DrawNextChar: L13BE: INX H ;------------------------------------------------------------------------------ ; DrawCharReadSwitches - Draw A characters from HL at DE; return A = INP_SWITCH. ;------------------------------------------------------------------------------ DrawCharReadSwitches: L13BF: CALL DrawString L13C2: IN INP_SWITCH L13C4: RET ;------------------------------------------------------------------------------ ; DrawOnOff - One blank column, then "ON " if Z is set, else "OFF". ;------------------------------------------------------------------------------ DrawOnOff: L13C5: INX D L13C6: LXI H,TxtOn L13C9: JZ L13CF L13CC: LXI H,TxtOff L13CF: MVI A,$03 L13D1: JMP DrawString TxtCoin: L13D4: .byte $43, $4F, $49, $4E ;"COIN" TxtOff: L13D8: .byte $4F, $46, $46 ;"OFF" TxtOn: L13DB: .byte $4F, $4E, $40 ;"ON " TxtPlayer: L13DE: .byte $50, $4C, $41, $51, $45, $52, $31, $32 ;"PLAYER12" L13E6: .byte $00 ;unused ;------------------------------------------------------------------------------ ; ClearRamTop - Zero A x 32 bytes downward from $4000 (A = 0: all of RAM). ; Done by pushing zeros, so it cannot return through the stack: the return ; address is taken off first and jumped to at the end. Leaves the stack at ; $2400 and interrupts off, and copies NEXT_PLAYER to PLAYER and ; NEXT_JUMPS_LEFT to JUMPS_LEFT. The script uses $FE (everything from $2040: ; balloon rows, objects, screen) and $F4 (from $2180: objects, state, screen). ;------------------------------------------------------------------------------ ClearRamTop: L13E7: DI L13E8: POP H ;HL = return address L13E9: LXI B,$0000 L13EC: LXI SP,$4000 ;Just past the end of RAM L13EF: PUSH B ;16 pushes = 32 bytes L13F0: PUSH B L13F1: PUSH B L13F2: PUSH B L13F3: PUSH B L13F4: PUSH B L13F5: PUSH B L13F6: PUSH B L13F7: PUSH B L13F8: PUSH B L13F9: PUSH B L13FA: PUSH B L13FB: PUSH B L13FC: PUSH B L13FD: PUSH B L13FE: PUSH B L13FF: DCR A L1400: JNZ L13EF ;Next 32 bytes L1403: LXI SP,$2400 ;Stack back at the top of work RAM L1406: LDA NEXT_PLAYER ;Player for this turn L1409: STA PLAYER L140C: LDA NEXT_JUMPS_LEFT ;Jumps left for this turn L140F: STA JUMPS_LEFT L1412: PCHL ;Return ;============================================================================== ; SECTION 8 Script commands ($1413-$1525) ; Handlers reached from MainLoop with DE -> the command's arguments. Each ; stores the new SCRIPT_PTR and returns to MainLoop. ;============================================================================== ;------------------------------------------------------------------------------ ; ScriptOps - Handler for each script opcode ($02, $04 ... $20). ;------------------------------------------------------------------------------ ScriptOps: L1413: .word OpText ;$02 TEXT L1415: .word OpDelay ;$04 DELAY L1417: .word OpTimeout ;$06 TIMEOUT L1419: .word OpGoto ;$08 GOTO L141B: .word OpSet ;$0A SET L141D: .word OpClear ;$0C CLEAR L141F: .word OpScore ;$0E SCORE L1421: .word OpBigText ;$10 BIGTEXT L1423: .word OpIfZ ;$12 IFZ L1425: .word OpIfNZ ;$14 IFNZ L1427: .word OpCoinStart ;$16 COINSTART L1429: .word OpRow ;$18 ROW L142B: .word OpDecCoin ;$1A DECCOIN L142D: .word OpIncCoin ;$1C INCCOIN L142F: .word OpTone ;$1E TONE L1431: .word OpQuiet ;$20 QUIET ;------------------------------------------------------------------------------ ; OpClear - CLEAR n: ClearRamTop with A = n. ;------------------------------------------------------------------------------ OpClear: L1433: XCHG ;HL -> argument L1434: MOV A,M L1435: INX H L1436: SHLD SCRIPT_PTR ;Script continues after it L1439: JMP ClearRamTop ;Returns to MainLoop (the address MainLoop pushed) ;------------------------------------------------------------------------------ ; OpBigText - BIGTEXT n, text, screen: DrawBigString. ;------------------------------------------------------------------------------ OpBigText: L143C: LXI H,DrawBigString L143F: JMP OpTextCommon ;------------------------------------------------------------------------------ ; OpText - TEXT n, text, screen: DrawString. ;------------------------------------------------------------------------------ OpText: L1442: LXI H,DrawString OpTextCommon: L1445: PUSH H ;The draw routine is entered by the RET below L1446: XCHG L1447: MOV A,M ;A = character count L1448: INX H L1449: MOV E,M ;Text address, L144A: INX H L144B: MOV D,M L144C: INX H L144D: PUSH D ;kept on the stack L144E: CALL ScriptWord ;DE = screen address; script pointer stored L1451: POP H ;HL = text address L1452: RET ;To the draw routine, which returns to MainLoop ;------------------------------------------------------------------------------ ; OpDelay - DELAY n: start TMR_SCRIPT; ScriptTimerDone may step the script. ;------------------------------------------------------------------------------ OpDelay: L1453: XRA A ;Clear SCRIPT_HOLD L1454: STA SCRIPT_HOLD L1457: XCHG L1458: MOV A,M L1459: STA TMR_SCRIPT ;Ticks L145C: INX H L145D: SHLD SCRIPT_PTR L1460: RET ;------------------------------------------------------------------------------ ; OpTimeout - TIMEOUT n, addr: start TMR_TIMEOUT and set where it sends the script. ;------------------------------------------------------------------------------ OpTimeout: L1461: XRA A ;Clear TIMEOUT_HOLD L1462: STA TIMEOUT_HOLD L1465: XCHG L1466: MOV A,M L1467: STA TMR_TIMEOUT ;Seconds L146A: INX H L146B: CALL ScriptWord ;DE = address L146E: XCHG L146F: SHLD TIMEOUT_PTR L1472: RET ;------------------------------------------------------------------------------ ; OpGoto - GOTO addr. ;------------------------------------------------------------------------------ OpGoto: L1473: XCHG L1474: MOV E,M L1475: INX H L1476: MOV D,M L1477: XCHG L1478: SHLD SCRIPT_PTR L147B: RET ;------------------------------------------------------------------------------ ; OpSet - SET value, addr: store a byte. ;------------------------------------------------------------------------------ OpSet: L147C: CALL ScriptByteWord ;A = value, DE = address L147F: STAX D L1480: RET ;------------------------------------------------------------------------------ ; OpScore - SCORE score, screen: draw a BCD score as 5 characters. ;------------------------------------------------------------------------------ OpScore: L1481: XCHG L1482: MOV C,M ;BC = address of the score L1483: INX H L1484: MOV B,M L1485: INX H L1486: PUSH H L1487: LXI H,TEXT_BUF ;Format into TEXT_BUF L148A: CALL FormatScore L148D: POP H L148E: CALL ScriptWord ;DE = screen address; script pointer stored L1491: LXI H,TEXT_BUF L1494: MVI A,$05 ;5 characters L1496: JMP DrawString ;------------------------------------------------------------------------------ ; OpIfZ - IFZ addr, target: jump if the byte at addr is 0. ;------------------------------------------------------------------------------ OpIfZ: L1499: CALL OpTestArgs L149C: JNZ L14A0 ;Not zero: continue after the arguments L149F: XCHG ;Zero: take the target L14A0: SHLD SCRIPT_PTR L14A3: RET ;------------------------------------------------------------------------------ ; OpIfNZ - IFNZ addr, target: jump if the byte at addr is not 0. ;------------------------------------------------------------------------------ OpIfNZ: L14A4: CALL OpTestArgs L14A7: JZ L14AB ;Zero: continue after the arguments L14AA: XCHG ;Not zero: take the target L14AB: SHLD SCRIPT_PTR L14AE: RET ;------------------------------------------------------------------------------ ; OpTestArgs - A = byte at the first argument (flags set), DE = second argument, HL -> next command. ;------------------------------------------------------------------------------ OpTestArgs: L14AF: XCHG L14B0: MOV E,M L14B1: INX H L14B2: MOV D,M L14B3: INX H L14B4: LDAX D L14B5: MOV E,M L14B6: INX H L14B7: MOV D,M L14B8: INX H L14B9: ANA A L14BA: RET ;------------------------------------------------------------------------------ ; OpCoinStart - COINSTART: if a coin is in, take it and jump to the script for the coinage setting. ; Also sets the jumps for the game (3 or 4, INP_DIP b6) and holds off both ; script timers so that neither the demo's DELAY nor its TIMEOUT disturbs the ; coin scripts. ;------------------------------------------------------------------------------ OpCoinStart: L14BB: LXI H,COINS L14BE: MOV A,M L14BF: ANA A L14C0: RZ ;No coin: the script goes on L14C1: DCR M ;Take the coin L14C2: STA SCRIPT_HOLD ;A is non-zero: SCRIPT_HOLD L14C5: STA TIMEOUT_HOLD ;and TIMEOUT_HOLD L14C8: IN INP_DIP L14CA: MOV D,A L14CB: RAL ;b6 to carry L14CC: RAL L14CD: MVI A,$03 ;3 jumps L14CF: JNC L14D3 L14D2: INR A ;or 4 L14D3: STA NEXT_JUMPS_LEFT L14D6: MOV A,D ;Coinage, b0-b1 L14D7: ANI $03 L14D9: MOV C,A L14DA: MVI B,$00 L14DC: LXI H,CoinageScripts ;Script for this coinage L14DF: DAD B L14E0: DAD B L14E1: MOV E,M L14E2: INX H L14E3: MOV D,M L14E4: XCHG L14E5: SHLD SCRIPT_PTR L14E8: RET ;------------------------------------------------------------------------------ ; OpRow - ROW y, addr: fill a balloon row. ;------------------------------------------------------------------------------ OpRow: L14E9: CALL ScriptByteWord ;A = y, DE = row L14EC: MOV B,A L14ED: XCHG ;------------------------------------------------------------------------------ ; FillBalloonRow - Fill the row at HL with 12 balloons at height B, 21 pixels apart from X = 0. ; Returns HL after the row. ;------------------------------------------------------------------------------ FillBalloonRow: L14EE: LXI D,$0C00 ;D = 12 balloons, E = X L14F1: MVI M,$80 ;Present L14F3: INX H L14F4: MOV M,E ;X L14F5: MOV A,E L14F6: ADI $15 ;21 pixels to the next one L14F8: MOV E,A L14F9: INX H L14FA: MOV M,B ;Y L14FB: INX H L14FC: DCR D L14FD: JNZ L14F1 L1500: RET ;------------------------------------------------------------------------------ ; ScriptByteWord - A = byte at DE, DE = word after it; SCRIPT_PTR -> after both. ;------------------------------------------------------------------------------ ScriptByteWord: L1501: XCHG L1502: MOV A,M L1503: INX H ;------------------------------------------------------------------------------ ; ScriptWord - DE = word at HL; SCRIPT_PTR -> after it. ;------------------------------------------------------------------------------ ScriptWord: L1504: MOV E,M L1505: INX H L1506: MOV D,M L1507: INX H L1508: SHLD SCRIPT_PTR L150B: RET ;------------------------------------------------------------------------------ ; OpDecCoin - DECCOIN: COINS - 1. ;------------------------------------------------------------------------------ OpDecCoin: L150C: LXI H,COINS L150F: DCR M L1510: RET ;------------------------------------------------------------------------------ ; OpIncCoin - INCCOIN: COINS + 1. ;------------------------------------------------------------------------------ OpIncCoin: L1511: LXI H,COINS L1514: INR M L1515: RET ;------------------------------------------------------------------------------ ; OpTone - TONE: steady tone (note $04). ;------------------------------------------------------------------------------ OpTone: L1516: MVI A,$3F L1518: OUT OUT_TONE_LO L151A: MVI A,$1A L151C: OUT OUT_TONE_HI L151E: RET ;------------------------------------------------------------------------------ ; OpQuiet - QUIET: tone off, sound board off. ;------------------------------------------------------------------------------ OpQuiet: L151F: XRA A L1520: OUT OUT_TONE_LO L1522: OUT OUT_SOUND L1524: RET L1525: .byte $00 ;unused ;============================================================================== ; SECTION 9 Contact handling and scoring ($1526-$17FF) ; CheckContact (interrupt) reports that the flyer's picture was drawn over ; something. Here the main loop works out what: floor, seesaw, ledge or ; balloon, from where the flyer is. ;============================================================================== ;------------------------------------------------------------------------------ ; HandleContact - Act on CONTACT_ROW: splat, launch from the seesaw, ledge bounce or balloon pop. ; Contact height = flyer Y + CONTACT_ROW. $D4 and below: the floor (Splat). ; $B0-$D3: the seesaw zone (LandOnSeesaw). Above: ContactAbove. ;------------------------------------------------------------------------------ HandleContact: L1526: LDA CONTACT_ROW L1529: ANA A ;Nothing touched L152A: RZ L152B: MOV B,A ;B = row + 1 L152C: LHLD FLYER_PTR L152F: MOV A,M L1530: ANI $08 L1532: RNZ ;Already splatted L1533: INX H L1534: INX H L1535: INX H ;-> CL_X L1536: MOV E,M ;E = flyer X L1537: INX H L1538: INX H ;-> CL_Y L1539: MOV A,B L153A: ADD M ;Height of the contact L153B: CPI $D4 ;On the floor? L153D: JC ContactNotFloor ;No ;------------------------------------------------------------------------------ ; Splat - The flyer hits the floor (or the wrong part of the seesaw). ; Puts it on the floor line with the first splat picture, shows one of four ; words above it and makes the miss sound. SplatStep finishes the animation. ; With YVEL 1 the clown sinks a line per update until SplatDone; once it is ; below line 223 the rows of its picture are written at $4000 and up, which ; is empty ROM space on this board, so they are lost. ;------------------------------------------------------------------------------ Splat: L1540: LHLD FLYER_PTR L1543: LXI B,CL_Y L1546: DAD B L1547: MVI M,$D4 ;On the floor L1549: DCX H L154A: MVI M,$01 ;YVEL 1: sinks a pixel per update L154C: DCX H L154D: DCX H L154E: MOV M,B ;XVEL 0 L154F: DCX H L1550: MVI M,$0F ;First splat picture L1552: DCX H L1553: MOV A,M L1554: ORI $08 ;Splatted: no contact, no gravity L1556: MOV M,A L1557: MVI A,$40 ;Erase by restoring the background L1559: STA ERASE_MODE L155C: MVI A,$03 ;Three pictures, L155E: STA TMR_SPLAT ;the first for 3 ticks L1561: STA SPLAT_CTR L1564: CALL Random L1567: ANI $03 ;One of four words L1569: MOV C,A L156A: MVI B,$00 L156C: LXI H,SplatWords L156F: DAD B L1570: DAD B L1571: DAD B ;3 characters each L1572: MOV A,E ;Flyer X L1573: CPI $08 L1575: JC L157A ;Centre the word: L1578: SUI $08 ;one character to the left, L157A: CPI $F0 L157C: JC L1581 L157F: MVI A,$E8 ;and not off the right side L1581: RAR ;/ 8: byte column L1582: RAR L1583: RAR L1584: ANI $1F L1586: MOV E,A L1587: MVI D,$38 ;DE = $3800 + column: line 160 L1589: MVI A,$03 L158B: CALL DrawString L158E: STA CONTACT_ROW ;A = 0: contact handled L1591: LDA GAME_ACTIVE ;Game on? L1594: ANA A L1595: RZ L1596: MVI A,$28 ;Miss sound L1598: OUT OUT_SOUND L159A: MVI A,$07 ;for 7 ticks L159C: STA TMR_SOUND_OFF L159F: RET ;------------------------------------------------------------------------------ ; SplatWords - Words shown at a splat, 3 characters each. ;------------------------------------------------------------------------------ SplatWords: L15A0: .byte $42, $41, $4D ;"BAM" L15A3: .byte $4F, $4F, $46 ;"OOF" L15A6: .byte $55, $47, $48 ;"UGH" L15A9: .byte $50, $4F, $57 ;"POW" ContactNotFloor: L15AC: CPI $B0 ;In the seesaw zone? L15AE: JC ContactAbove ;No: higher up ;------------------------------------------------------------------------------ ; LandOnSeesaw - Contact in the seesaw zone: launch the rider if the flyer came down on the raised end. ; The landing zone is 28 pixels wide: flyer X from SEESAW_DRAWN_X - 12 when ; the right end is down (the left end is up), 20 further right otherwise. ; Outside it the flyer splats. Inside, the position in the zone (0-6) sets the ; launch: the middle goes straight up, either side sends the rider that way ; with an X speed that grows with the distance and with SPEED_LEVEL. The ; rider becomes the flyer with YVEL = -(SPEED_LEVEL + 5); the old flyer ; becomes the rider on the end it landed on; the seesaw starts tipping. ; Every launch scores 10 points. ;------------------------------------------------------------------------------ LandOnSeesaw: L15B1: LXI H,SEESAW_STATE L15B4: MOV A,M L15B5: ANI $20 ;Which end is down? L15B7: MVI D,$00 ;Right end down: zone at the left end L15B9: JNZ L15BE L15BC: MVI D,$14 ;Left end down: zone 20 pixels further right L15BE: INX H ;-> SEESAW_DRAWN_X L15BF: MOV A,E ;Flyer X L15C0: ADI $0C L15C2: SUB D ;- zone start L15C3: SUB M L15C4: CPI $1C ;Inside the 28 pixels? L15C6: JNC Splat ;No: splat L15C9: RAR ;Position / 4: L15CA: RAR L15CB: ANI $07 ;0-6 L15CD: MOV C,A L15CE: DCX H L15CF: MOV A,M ;Seesaw: L15D0: ORI $40 ;start tipping L15D2: MOV M,A L15D3: MVI B,$00 L15D5: LHLD RIDER_PTR ;The rider L15D8: PUSH H L15D9: LHLD FLYER_PTR L15DC: MVI M,$A0 ;Old flyer: in use, blank its last picture L15DE: SHLD RIDER_PTR ;It is the rider now L15E1: INX H L15E2: INX H L15E3: MOV M,B ;XVEL 0 L15E4: INX H L15E5: INX H L15E6: MOV M,B ;YVEL 0 L15E7: INX H L15E8: MVI M,$C4 ;Standing on the seesaw L15EA: MOV A,C L15EB: SUI $03 ;Middle of the zone? L15ED: JNZ L15FA ;No L15F0: MOV E,A ;Straight up: XVEL 0 L15F1: LDA SPEED_LEVEL L15F4: ADI $05 ;D = launch speed L15F6: MOV D,A L15F7: JMP L160C L15FA: JNC L1608 ;Right of the middle L15FD: CMA ;Left: distance 1-3 L15FE: INR A L15FF: CALL LaunchXSpeed ;X speed for it L1602: CMA ;to the left L1603: INR A L1604: MOV E,A L1605: JMP L160C L1608: CALL LaunchXSpeed ;X speed, to the right L160B: MOV E,A L160C: MOV A,D ;YVEL = -speed L160D: CMA L160E: INR A L160F: POP H ;The old rider L1610: MVI C,$04 ;-> CL_YVEL L1612: DAD B L1613: MOV M,A L1614: DCX H ;CL_X: L1615: MOV A,M L1616: CPI $F2 ;keep it on the screen L1618: JC L161D L161B: MVI M,$F1 L161D: DCX H L161E: MOV M,E ;CL_XVEL L161F: DCX H L1620: DCX H L1621: MVI M,$A0 ;In use, blank its rider picture L1623: SHLD FLYER_PTR ;It is the flyer now L1626: LXI H,REBOUND_STEP_CTR ;Every 4th launch: L1629: INR M L162A: MOV A,M L162B: CPI $04 L162D: JC L163D L1630: MOV M,B L1631: LXI H,REBOUND_SPEED ;popping a balloon on the way up sends the flyer down faster L1634: INR M L1635: MOV A,M L1636: CPI $05 L1638: JC L163D L163B: MVI M,$04 ;up to 4 L163D: LXI H,GRAVITY_STEP_CTR ;Every 2nd launch: L1640: INR M L1641: MOV A,M L1642: CPI $02 L1644: JC L1654 L1647: MOV M,B L1648: LXI H,GRAVITY_PERIOD ;gravity pulls less often L164B: INR M L164C: MOV A,M L164D: CPI $09 L164F: JC L1654 L1652: MVI M,$08 ;at most every 8 ticks L1654: LXI H,SPEED_STEP_CTR ;Every 3rd launch: L1657: INR M L1658: MOV A,M L1659: CPI $03 L165B: JC L166C L165E: MOV M,B L165F: LXI H,SPEED_LEVEL ;launches get faster L1662: MOV A,M L1663: INR A L1664: CPI $05 L1666: JC L166B L1669: MVI A,$04 ;up to level 4 L166B: MOV M,A L166C: MVI A,$03 ;No contact for 3 ticks L166E: STA TMR_HIT_LOCKOUT L1671: CALL ClearContact ;Contact handled L1674: LDA GAME_ACTIVE ;Game on? L1677: ANA A L1678: RZ L1679: MVI A,$18 ;Springboard sound L167B: OUT OUT_SOUND L167D: MVI A,$07 ;for 7 ticks L167F: STA TMR_SOUND_OFF L1682: LXI B,$0001 ;10 points: falls into AddScore ;------------------------------------------------------------------------------ ; AddScore - Add BC (BCD, tens of points: B high, C low) to the current player's score; award bonuses. ; Bonus game (INP_DIP b2-b3: at 9000, 11000 or 13000): once per game, and not ; in a game that follows a bonus game; adds COINS_PER_GAME to COINS and ; shows ADDITIONAL GAME. Extra jump (INP_DIP b5: at 3000 or 4000): once per ; player; sets JUMPS_AGAIN, plays the bonus tune, freezes for 3 seconds and ; shows BONUS / PLAYER JUMPS AGAIN. ;------------------------------------------------------------------------------ AddScore: L1685: LDA GAME_ACTIVE L1688: ANA A L1689: RZ ;Attract mode: no score L168A: LDA PLAYER ;Which player? L168D: ANA A L168E: LXI H,P1_EXTRA_JUMP ;HL -> that player's extra-jump flag L1691: LXI D,P1_SCORE+1 ;DE -> low byte of the score L1694: JZ L169B ;Player 1 L1697: INX H L1698: LXI D,P2_SCORE+1 L169B: LDAX D L169C: ADD C ;Low byte L169D: DAA L169E: STAX D L169F: DCX D L16A0: LDAX D L16A1: ADC B ;High byte L16A2: DAA L16A3: STAX D L16A4: MOV B,A ;B = thousands and hundreds L16A5: LDA PREV_BONUS_GAME ;Was the last game a bonus game? L16A8: ANA A L16A9: JNZ CheckExtraJump ;Yes: no bonus game in this one L16AC: LXI D,BONUS_GAME ;Already awarded? L16AF: LDAX D L16B0: ANA A L16B1: JNZ CheckExtraJump L16B4: IN INP_DIP ;Bonus game setting L16B6: ANI $0C L16B8: JZ CheckExtraJump ;Off L16BB: RAR ;2, 4, 6 L16BC: ADI $06 ;8, $10, $12 in BCD: L16BE: DAA L16BF: CMP B ;score above 8999, 10999 or 12999? L16C0: JNC CheckExtraJump ;Not yet L16C3: LXI H,COINS_PER_GAME ;The coins this game cost L16C6: MOV A,M L16C7: DCX H L16C8: STAX D ;BONUS_GAME: awarded L16C9: ADD M ;Give them back L16CA: MOV M,A L16CB: LXI H,TxtAdditionalGame ;"ADDITIONAL GAME" L16CE: LXI D,$3E88 ;Line 212, column 8 L16D1: MVI A,$0F L16D3: JMP DrawString CheckExtraJump: L16D6: IN INP_DIP ;Extra jump setting L16D8: ANI $20 L16DA: MVI C,$03 ;At 3000 L16DC: JZ L16E0 L16DF: INR C ;or 4000 L16E0: MOV A,B ;Score thousands L16E1: CMP C L16E2: RC ;Not there yet L16E3: MOV A,M ;This player had it already? L16E4: ANA A L16E5: RNZ L16E6: INR M ;Now it has L16E7: LXI H,BonusTune ;Bonus tune L16EA: SHLD TUNE_PTR L16ED: MVI A,$5A ;Freeze for 90 ticks (3 s) L16EF: STA TMR_FREEZE L16F2: STA FREEZE_REQ L16F5: STA JUMPS_AGAIN ;JUMPS_AGAIN L16F8: LXI H,TxtBonus ;"BONUS" in big letters L16FB: LXI D,$3486 L16FE: MVI A,$05 L1700: CALL DrawBigString L1703: LXI H,TxtPlayerJumpsAgain ;"PLAYER JUMPS AGAIN" L1706: LXI D,$3E87 ;Line 212, column 7 L1709: MVI A,$12 ;18 characters L170B: JMP DrawString ;------------------------------------------------------------------------------ ; LaunchXSpeed - A = distance from the middle of the zone (1-3). Returns A = E = X speed, D = launch speed. ; X speed = (SPEED_LEVEL + 5) x 3 x distance / 16. ;------------------------------------------------------------------------------ LaunchXSpeed: L170E: MOV E,A L170F: XRA A L1710: ADI $03 ;E = 3 x distance L1712: DCR E L1713: JNZ L1710 L1716: MOV E,A L1717: LDA SPEED_LEVEL ;D = SPEED_LEVEL + 5 L171A: ADI $05 L171C: MOV D,A L171D: XRA A L171E: ADD D ;A = D x E L171F: DCR E L1720: JNZ L171E L1723: RRC ;/ 16 L1724: RRC L1725: RRC L1726: RRC L1727: ANI $0F L1729: RET ;------------------------------------------------------------------------------ ; ContactAbove - Contact above the seesaw zone: balloon rows, ledges, or nothing. ;------------------------------------------------------------------------------ ContactAbove: L172A: CPI $5C ;In the balloon rows (above $5C)? L172C: JC ContactBalloons L172F: MOV A,E ;No: flyer X L1730: CPI $18 ;Within 24 pixels of the left side? L1732: JC LedgeBounce L1735: CPI $D8 ;or of the right side? L1737: JC ClearContact ;No: nothing there ;------------------------------------------------------------------------------ ; LedgeBounce - The flyer touched a ledge: if it is falling, bounce it up and away from the wall. ;------------------------------------------------------------------------------ LedgeBounce: L173A: LHLD FLYER_PTR L173D: INX H L173E: INX H L173F: INX H L1740: INX H L1741: CALL ClearContact ;Contact handled L1744: MOV A,M ;YVEL L1745: ANA A L1746: RM ;Going up: no bounce L1747: MVI M,$FE ;2 up L1749: DCX H L174A: MOV A,M ;X: which side? L174B: ANA A L174C: DCX H L174D: MVI M,$01 ;XVEL: 1 right off the left wall, L174F: JP L1754 L1752: MVI M,$FF ;1 left off the right wall L1754: DCX H L1755: MVI M,$10 ;Picture $10: crouched L1757: RET ;------------------------------------------------------------------------------ ; ContactBalloons - Contact above line $5C: find the balloon row by height. ;------------------------------------------------------------------------------ ContactBalloons: L1758: MVI B,$00 ;Row 0: bottom, Y $4E L175A: LXI H,P1_ROW_BOT L175D: MVI D,$4E L175F: CMP D ;Contact at or below the bottom row? L1760: JNC PopBalloon L1763: LXI H,P1_ROW_MID ;Row 1: middle, Y $38 L1766: MVI D,$38 L1768: INR B L1769: CMP D L176A: JNC PopBalloon L176D: LXI H,P1_ROW_TOP ;Row 2: top, Y $24 L1770: MVI D,$24 L1772: INR B L1773: CMP D L1774: JNC PopBalloon ;Above the top row: nothing, falls into ClearContact ;------------------------------------------------------------------------------ ; ClearContact - CONTACT_ROW = 0: the contact has been dealt with. ;------------------------------------------------------------------------------ ClearContact: L1777: XRA A L1778: STA CONTACT_ROW L177B: RET ;------------------------------------------------------------------------------ ; PopBalloon - Find the balloon the flyer touched in row HL (B = row number, D = its Y) and pop it. ; A balloon is hit when its X is within flyer X - 8 .. flyer X + 15. The ; balloon is removed and blanked; the flyer gets a random tumble picture and ; bounces: up at 1 if it was falling, down at REBOUND_SPEED if it was rising. ; Scores 20, 50 or 100 with the matching pop sound. ;------------------------------------------------------------------------------ PopBalloon: L177C: MOV A,B ;Remember the row for the score L177D: STA HIT_ROW L1780: LDA PLAYER ;Which player's row? L1783: ANA A L1784: JZ L178B L1787: LXI B,P2_OFFSET L178A: DAD B L178B: MVI B,$0C ;12 balloons L178D: MOV C,E ;C = flyer X L178E: MOV A,M L178F: ANA A L1790: JP NextBalloon ;Popped already L1793: INX H L1794: MOV A,M L1795: DCX H L1796: MOV E,A ;E = balloon X L1797: SUB C ;- flyer X L1798: ADI $08 ;+ 8 L179A: CPI $18 ;Within 24? L179C: JNC NextBalloon ;No L179F: MVI A,$03 ;No contact for 3 ticks L17A1: STA TMR_HIT_LOCKOUT L17A4: MVI M,$00 ;Balloon gone L17A6: CALL Random L17A9: ANI $07 ;Random picture, L17AB: INR A ;tumble 1-8 L17AC: LHLD FLYER_PTR L17AF: MVI M,$A0 ;In use, blank this picture L17B1: INX H L17B2: MOV M,A ;CL_FRAME L17B3: INX H L17B4: INX H L17B5: INX H L17B6: MOV A,M ;CL_YVEL L17B7: ANA A L17B8: MVI M,$FF ;Bounce up at 1 L17BA: JP L17C1 ;It was falling L17BD: LDA REBOUND_SPEED ;It was rising: knock it down L17C0: MOV M,A L17C1: CALL ScreenAddr ;Screen address of the balloon (X = E, Y = D) L17C4: MVI C,$1F ;To the next line: 32 - 1 L17C6: XCHG L17C7: MVI A,$08 ;8 rows L17C9: MOV M,B ;Blank its two bytes L17CA: INX H L17CB: MOV M,B L17CC: DAD B L17CD: DCR A L17CE: JNZ L17C9 L17D1: STA CONTACT_ROW ;A = 0: contact handled L17D4: LDA GAME_ACTIVE ;Game on? L17D7: ANA A L17D8: RZ L17D9: LDA HIT_ROW ;Row popped L17DC: MOV C,A L17DD: LXI H,PopTable ;Points and sound per row L17E0: DAD B L17E1: DAD B L17E2: MOV C,M ;C = points / 10 L17E3: INX H L17E4: MOV A,M L17E5: OUT OUT_SOUND ;Pop sound L17E7: MVI A,$07 ;for 7 ticks L17E9: STA TMR_SOUND_OFF L17EC: JMP AddScore ;Add the points (B = 0) NextBalloon: L17EF: INX H L17F0: INX H L17F1: INX H L17F2: DCR B L17F3: JNZ L178E L17F6: JMP ClearContact ;No balloon there ;------------------------------------------------------------------------------ ; PopTable - Per row (bottom, middle, top): points / 10 in BCD, OUT_SOUND value. ;------------------------------------------------------------------------------ PopTable: L17F9: .byte $02, $09 ;bottom row: 20 points, OUT_SOUND value L17FB: .byte $05, $0A ;middle row: 50 points, OUT_SOUND value L17FD: .byte $10, $0C ;top row: 100 points, OUT_SOUND value L17FF: .byte $00 ;unused