;Clowns (Midway, 1978) - hardware map, RAM variables and equates for ;clowns_program_rom.asm (MAME 'clowns', rev. 2). ;No original source is known: all names were given for this disassembly. ;Hardware notes follow the MAME driver mw8080bw.cpp. ;Generated by disasm/emit_defines.py; every symbol the program listing uses is here. ;----------------------------------[ Memory map ]---------------------------------- .alias ProgramRom $00 ;Through $17FF. Six 1K ROMs H G F E D C (clowns_program_rom.asm). .alias WorkRam $2000 ;Through $23FF. Variables; the 8080 stack grows down from $2400. .alias VideoRam $2400 ;Through $3FFF. 256 x 224 bitmap, 32 bytes per line, bit 0 = leftmost pixel. Address = $2400 + 32*Y + X/8. .alias EmptyRomSpace $4000 ;Through $5FFF. The board's second ROM area, not fitted on Clowns: writes are ignored. A splatted clown sinking below line 223 is drawn into it. .alias RamMirror $6000 ;Through $7FFF. $2000-$3FFF again (only 15 address bits are decoded). Not used. ;----------------------------------[ Input ports ]---------------------------------- ;8080 I/O space (IN). Port numbers repeat every 4. .alias INP_PADDLE $00 ;IN0. Paddle position 0-255 of the player selected by OUT_MISC bit 1. .alias INP_SWITCH $01 ;IN1, active low. b4 2-player start, b5 1-player start, b6 coin. .alias INP_DIP $02 ;IN2. b0-b1 coinage (0 1C/1P, 1 1C/2P, 2 2C/2P, 3 2C/1P), b2-b3 bonus game (0 none, 9000, 11000, 13000), b4 balloon resets (0 each row, 1 all rows), b5 extra jump at 3000/4000, b6 jumps 3/4, b7 self test. .alias INP_SHIFT $03 ;MB14241 shifter result: the last two bytes written, shifted by the count. ;----------------------------------[ Output ports ]---------------------------------- ;8080 I/O space (OUT). .alias OUT_SHIFT_AMT $01 ;MB14241 shift count (low 3 bits = X position within the byte). .alias OUT_SHIFT_DATA $02 ;MB14241 shift data. .alias OUT_MISC $03 ;b0 coin counter, b1 paddle select (1 = player 2). Shadow in OUT3_SHADOW. .alias OUT_WATCHDOG $04 ;Any write clears the watchdog. .alias OUT_TONE_LO $05 ;Tone generator: b0 tone enable, b1-b5 low five bits of the period. .alias OUT_TONE_HI $06 ;Tone generator: b0-b5 high six bits of the period. .alias OUT_SOUND $07 ;b0 pop (bottom row), b1 pop (middle row), b2 pop (top row), b3 sound enable, b4 springboard hit, b5 miss (rising edge). ;----------------------------------[ Work RAM: script, scores, timers ]---------------------------------- .alias SCRIPT_PTR $2000 ;2 bytes. Game script program counter (the interpreter is MainLoop). .alias SECOND_PRESCALE $2002 ;Counts 30 odd frames down to one TMR_TIMEOUT tick (about a second). .alias TIMEOUT_PTR $2003 ;2 bytes. Script address taken when TMR_TIMEOUT runs out (script TIMEOUT command). .alias GAME_ACTIVE $2005 ;0 = attract mode, 1 = a game is being played. .alias COIN_SW_PREV $2006 ;Last coin switch state ($40 = down) for edge detection. .alias RNG_SEED $2007 ;8-bit shift-register random number. .alias COINS $2009 ;Coins inserted and not yet spent. .alias COINS_PER_GAME $200A ;Coins the current game cost; a bonus game adds this many back to COINS. .alias SCRIPT_HOLD $200B ;Non-zero: an expired TMR_SCRIPT does not step the script past its WAIT. .alias TIMEOUT_HOLD $200C ;Non-zero: an expired TMR_TIMEOUT does not jump to TIMEOUT_PTR. .alias FRAME_CTR $200D ;Incremented each frame; bit 0 picks seesaw frame (even) or balloon frame (odd). .alias P1_SCORE $200E ;2 bytes. Player 1 score, BCD, high byte first. Shown with a fixed 0 appended (tens of points). .alias JUMPS_LEFT $2010 ;Jumps (lives) left, shown after JUMPS. .alias P2_SCORE $2011 ;2 bytes. Player 2 score, same format as P1_SCORE. .alias PADDLE_POS $2013 ;Wanted seesaw X: the paddle (read at vblank when PADDLE_ENABLE) or the attract autopilot. .alias OUT3_SHADOW $2014 ;Copy of OUT_MISC: b0 coin counter, b1 paddle select. .alias HI_SCORE $2015 ;2 bytes. High score, BCD, high byte first. Below $2040, so it survives the script CLEAR. .alias REFILL_PENDING $2017 ;Non-zero while a cleared row waits to be refilled: the row's Y (each-row mode) or 1 (all rows). .alias REFILL_ROW_PTR $2018 ;2 bytes. Balloon row (or first row) that TMR_REFILL will refill. .alias NEXT_PLAYER $201A ;Player for the next turn; ClearRamTop copies it to PLAYER. .alias NEXT_JUMPS_LEFT $201B ;Jumps left for the next turn; ClearRamTop copies it to JUMPS_LEFT. .alias SPEED_LEVEL $201C ;0-4. Launch speed is SPEED_LEVEL+5; goes up every third launch. .alias TUNE_TEMPO $201D ;Frames per beat of the tune being played. .alias TUNE_TICKS $201E ;Frames left in the current beat. .alias TUNE_BEATS $201F ;Beats left in the current note. .alias TUNE_GAP $2020 ;Frames of silence owed before the next note. .alias TUNE_ON $2021 ;Non-zero: PlayTune runs. .alias TUNE_PTR $2022 ;2 bytes. Next byte of the tune. .alias JUMPS_AGAIN $2024 ;Non-zero: the player earned an extra jump; the turn does not pass and no jump is used. .alias PREV_BONUS_GAME $2025 ;BONUS_GAME of the game that just ended; a game played on a bonus cannot win another. .alias TMR_TIMEOUT $2028 ;Slow timer (seconds). Expiry -> EVT_TIMEOUT b0 -> script jumps to TIMEOUT_PTR. .alias TMR_SCRIPT $2029 ;30 Hz timers $2029-$2030 (TickTimers). This one: script DELAY; expiry steps past the WAIT. .alias TMR_SOUND_OFF $202A ;Expiry ends the pop / hit / miss sound (OUT_SOUND = $08). .alias TMR_WALK $202B ;Expiry advances the walk animation of the clown being served. .alias TMR_SERVE_JUMP $202C ;Expiry makes the served clown jump off its ledge. .alias TMR_GRAVITY $202D ;Expiry adds 1 to the flyer's Y velocity; reloaded from GRAVITY_PERIOD. .alias TMR_SPLAT $202E ;Expiry steps the splat animation. .alias TMR_HIT_LOCKOUT $202F ;While running, sprite contact is ignored (after a launch or a pop). No expiry action. .alias TMR_REFILL $2030 ;Expiry refills the cleared balloon row(s). .alias TMR_COIN_CTR $2031 ;30 Hz timers $2031-$2033. This one: expiry ends the coin counter pulse. .alias TMR_TUMBLE $2032 ;Paces the flyer's tumble frames. No expiry action; polled by AnimateFlyer. .alias TMR_FREEZE $2033 ;Expiry ends the bonus freeze and erases the BONUS message. ;----------------------------------[ Work RAM: balloon rows ]---------------------------------- .alias P1_ROW_TOP $2040 ;36 bytes. Balloon rows: 12 balloons x (state b7 = present, X, Y). Player 1 top row (Y $24, 100 points). .alias P2_ROW_TOP $2064 ;36 bytes. Player 2 top row. Every player 2 row is P2_OFFSET above player 1's. .alias P1_ROW_MID $2088 ;36 bytes. Player 1 middle row (Y $38, 50 points). .alias P2_ROW_MID $20AC ;36 bytes. Player 2 middle row. .alias P1_ROW_BOT $20D0 ;36 bytes. Player 1 bottom row (Y $4E, 20 points). .alias P2_ROW_BOT $20F4 ;36 bytes. Player 2 bottom row. ;----------------------------------[ Work RAM: seesaw, players, clown objects ]---------------------------------- .alias SEESAW_STATE $2118 ;b7 on screen, b6 tipping, b5 right end down (clown waits on the right), b0-b3 picture 0-4. .alias SEESAW_DRAWN_X $2119 ;X the seesaw was last drawn at (erased from here next time). .alias P1_EXTRA_JUMP $211B ;Non-zero once player 1 has been given the extra jump. .alias P2_EXTRA_JUMP $211C ;Same for player 2. .alias PLAYER $211D ;$00 = player 1, $FF = player 2. .alias TWO_PLAYERS $211E ;Non-zero in a two-player game. .alias BONUS_GAME $211F ;Non-zero once the bonus game has been awarded in this game. .alias CLOWN_A $2180 ;64 bytes. Clown object (see the CL_ offsets). .alias CLOWN_B $21C0 ;64 bytes. Second clown object. ;----------------------------------[ Work RAM: text buffer and game state ]---------------------------------- .alias TEXT_BUF $2200 ;15 bytes. Characters of the score line: player 1 score (5), jumps left (1), player 2 score (5). .alias BONUS_BUF $220F ;5 bytes. Characters of the row bonus value. .alias EVT_TIMEOUT $2219 ;b0 set by the interrupt when TMR_TIMEOUT ran out; taken by CheckTimeout. .alias EVT_TIMERS $221A ;Expiry bits for $2029-$2030 (b7 = $2029 ... b0 = $2030); taken by RunTimerEvents. .alias EVT_TIMERS2 $221B ;Expiry bits for $2031-$2033 (b2 = $2031 ... b0 = $2033); taken by RunTimerEvents2. .alias SEESAW_X $221D ;Seesaw X: PADDLE_POS limited to $D7. .alias SERVE_REQUEST $221E ;Non-zero: ServeClown sets up both clowns for a new jump. .alias SERVING $221F ;Non-zero while the served clown walks on its ledge (no gravity, no tumbling). .alias WALK_PHASE $2220 ;0-3, steps the walk picture +1 +1 -1 -1. .alias GRAVITY_PERIOD $2221 ;TMR_GRAVITY reload: 5 in attract, 4 at the start of a jump, up to 8. .alias GRAVITY_STEP_CTR $2222 ;Every 2nd launch raises GRAVITY_PERIOD. .alias SPLAT_CTR $2223 ;Splat pictures left. .alias FLYER_PTR $2224 ;2 bytes. Clown object in the air (or being served). .alias RIDER_PTR $2226 ;2 bytes. Clown object standing on the seesaw. .alias ERASE_MODE $2228 ;OR-ed into the flyer's state when it is drawn: $40 put the saved background back, $20 blank the box. .alias HIT_ROW $2229 ;Row of the balloon just popped: 0 bottom, 1 middle, 2 top. .alias START1_DOWN $222A ;$20 while the 1-player start button is down. .alias START2_DOWN $222B ;$10 while the 2-player start button is down. .alias PLAYFIELD_ON $222C ;Non-zero: the floor and the four ledges are redrawn every main loop pass. .alias PADDLE_ENABLE $222D ;Non-zero: the vblank interrupt copies the paddle to PADDLE_POS. .alias AUTOPILOT $222E ;Non-zero: attract mode steers the seesaw under the flyer. .alias DIGIT_INDEX $2230 ;Which character of TEXT_BUF DrawNextDigit shows next. .alias FLYER_HIGH $2231 ;Non-zero when the flyer is above Y $50: it is then updated at mid-screen, else at vblank. .alias FREEZE $2232 ;Non-zero: flyer and balloons stand still (bonus message). .alias FREEZE_REQ $2233 ;Copied to FREEZE after the flyer's next update. .alias CONTACT_ROW $2234 ;Set by the interrupt: 1 + sprite row where the flyer first touched something; cleared by HandleContact. .alias BALLOON_PHASE $2235 ;0-5, which entry of BalloonTasks runs this odd frame. .alias SPEED_STEP_CTR $2236 ;Every 3rd launch raises SPEED_LEVEL. .alias REBOUND_STEP_CTR $2237 ;Every 4th launch raises REBOUND_SPEED. .alias REBOUND_SPEED $2238 ;0-4. Downward speed given to a flyer that pops a balloon on the way up. ;----------------------------------[ Constants ]---------------------------------- ;Clown object .alias CL_STATE $00 ;b7 in use, b6 put back the saved background before the next draw, b5 blank the old box, b4 slow (moves every 4th update), b3 splatted, b0-b2 slow tick. .alias CL_FRAME $01 ;Picture number, index into ClownPictures. .alias CL_XVEL $02 ;Added to X at every update. .alias CL_X $03 ;X, 0-$F1. .alias CL_YVEL $04 ;Added to Y at every update. .alias CL_Y $05 ;Y of the top of the picture. .alias CL_SCREEN $06 ;Video RAM address the picture was drawn at (2 bytes). .alias CL_ROWS $08 ;Rows drawn. .alias CL_WIDTH $09 ;Screen bytes per row: picture bytes + 1 for the shift (3 for the flyer, 2 for the rider). .alias CL_SAVED $0A ;Background bytes saved while drawing, CL_WIDTH per row. ;Balloons .alias P2_OFFSET $24 ;Player 2's balloon row = player 1's + $24 (12 balloons x 3 bytes).