[request] Not exactly an ST port.... Black Tiger Redux?

[chadderack]

Originally Posted by jotd

way to go: disassemble the thing, then rewrite your own.

That's the approach I've always thought was best--because there's likely things a coder has never seen in the arcade version. Hidden rooms? Hidden levels? That kind of thing.

The most important would be to understand level layout: tiles, enemy placement and types.

Once you have that, you don't need much more, maybe some A.I. part. See Kroah's excellent reverse engineer of Gods and others http://bringerp.free.fr/RE/index.php5

Sweet. I'll check that out. Thanks!

More & more I think that A.I. in those games is pretty much invisible: the player sees an enemy and kills it before he can notice how the enemy moves Frustrating for the coder...

I think the AI is encoded into structures with its own higher level language.
EX:

(pseudo code)

01 02 04 06

ENEMY_TYPE_1 = 01 ; maybe the ape-like brute character
ENEMY_DECISION_TYPE = 02 ; 02 means either follow or flee
ENEMY_DECISION = 04; follow
COUNTER = 06; for the next 6 moves

I'll have to decipher how that part works to decode the AI stuff.
I do see a lot of structures in the code that look similar.

That's how I did the bagman remake: understand how enemies move (specially the speed ratios player/enemies) and use the same method. In that case, I was more interested in the A.I (it's a pacman-like game) than the rest.

Very good.

I ignored all graphics, just ripped some maps and enemy automated movement table, and the game plays almost the same than the original.

All those dreams about automatic converters are just... dreams.

Yeah. If there were a way to stop time and work on games for a few years, then start time again...

....

Here's a morsel from the audiocpu. I've found the individual sounds... some of which I've never heard before. There are a few fanfare sounds that never seem to play (and they don't seem to be called in code either).

What finding the sounds did was allow me to not just find the functions in the maincpu... I traced those back into the audiocpu and single stepped through the code after triggering each sound from the maincpu.

I don't know whether the format is direct wav samples or instructions or combinations of lookups into wav tables yet... but I know where the sounds are

                             SOUNDS_TABLE                                    XREF[1]:     Maybe_PlaySoundEffect:020e(*)  
        ram:0dc1 00 ff           dw         FF00h                                            Sound 0: FF stops music playing
        ram:0dc3 49 0e           dw         PLAYER_LOSES_VITALITY_SOUND                      = 8Fh
        ram:0dc5 9e 0e           dw         PLAYER_DEATH_SOUND                               = 8Fh
        ram:0dc7 7f 0f           dw         ENEMY_INJURED_BLOOP_SOUND                        = CFh
        ram:0dc9 d4 0f           dw         ENEMY_DEFEATED_SOUND                             = CFh
        ram:0dcb fe 0f           dw         ITEM_TAKEN_SOUND                                 = 88h
        ram:0dcd 7b 10           dw         PLAYER_TAKES_ZENNY_COIN_SOUND                    = 88h
        ram:0dcf f5 10           dw         FIRE_PILLAR_WARNING_SOUND                        = 88h
        ram:0dd1 5e 11           dw         POT_BREAKS_REVEALS_COIN_SOUND                    = C8h
        ram:0dd3 c7 11           dw         FIRE_PILLAR_SOUND                                = C8h
        ram:0dd5 08 12           dw         SMALL_EXPLOSION_SOUND                            = C8h
        ram:0dd7 32 12           dw         WEAPON_CLASH_METALLIC_BATTLE_SOUND               = 88h
        ram:0dd9 84 12           dw         KILL_BAT_SOUND                                   = C8h
        ram:0ddb ae 12           dw         PLAYER_EARNS_EXTRA_LIFE_SOUND                    = 8Fh
        ram:0ddd 64 13           dw         POT_BREAKS_SOUND                                 = 88h
        ram:0ddf bc 13           dw         PLAYER_DISCOVERS_TREASURE_SOUND                  = C8h
        ram:0de1 86 14           dw         BIG_BOSS_HIT_SOUND                               10
        ram:0de3 b0 14           dw         TIME_EXPIRING_SOUND                              = 81h
        ram:0de5 ee 14           dw         PLAYER_GETS_ITEM_FROM_OLD_MAN_SOUND              = 88h
        ram:0de7 cc 15           dw         BOOM_EXPLOSION_SOUND                             = C8h
        ram:0de9 0d 16           dw         UNKNOWN_ALARM_SOUND                              = 81h
        ram:0deb 4e 16           dw         IMPACT_SOUND                                     = C8h
        ram:0ded 78 16           dw         CLASH_SPINNING_COIN_SOUND                        = C8h
        ram:0def a2 16           dw         PLAYER_LOSES_ARMOR_SOUND                         = 8Fh
        ram:0df1 08 17           dw         MICHELIN_MAN_FIREBREATHING_SOUND                 = C8h
        ram:0df3 35 17           dw         FIRETHROWER_TAUNT_SOUND                          = C8h
        ram:0df5 b2 17           dw         PLAYER_CLIMB_SOUND                               = 88h
        ram:0df7 c8 17           dw         FLAIL_EMPTY_HIT_SOUND                            = 88h
        ram:0df9 de 17           dw         PLAYER_LANDS_ON_PLATFORM_SOUND                   = 88h
        ram:0dfb 1c 18           dw         PLAYER_ASCENDS_DURING_CUTSCENE_SOUND             = 88h
        ram:0dfd 32 18           dw         PLAYER_GRABS_LADDER_SOUND                        = 88h
        ram:0dff 01 ff           dw         FF01h                                            1f: stops playing music
        ram:0e01 10 1b           dw         COIN_OR_CREDIT_ADDED_SOUND                       = 4Fh    O
        ram:0e03 8c 1b           dw         LEVEL_1_MUSIC                                    Level 1 music
        ram:0e05 de 1f           dw         LEVEL_2_MUSIC                                    = 06h
        ram:0e07 ef 23           dw         LEVEL_3_MUSIC                                    = 06h
        ram:0e09 b7 27           dw         LEVEL_4_MUSIC                                    = 06h
        ram:0e0b 27 2d           dw         LEVEL_5_MUSIC                                    = 06h
        ram:0e0d 07 32           dw         LEVEL_6_MUSIC                                    = 06h
        ram:0e0f c4 35           dw         LEVEL_7_MUSIC                                    = 06h
        ram:0e11 7c 3a           dw         LEVEL_8_MUSIC                                    Level 8 music
        ram:0e13 cb 3f           dw         BOSS_MUSIC_01                                    = 06h
        ram:0e15 f5 41           dw         FIGHT_DRAGON_MUSIC_01                            = 06h
        ram:0e17 8b 44           dw         FIGHT_DRAGON_MUSIC_02                            = 06h
        ram:0e19 70 47           dw         OLD_MAN_SHOP_MUSIC                               = 06h
        ram:0e1b 7e 49           dw         DUNGEON_MUSIC_01                                 = 06h
        ram:0e1d 96 4b           dw         ENTER_INITIALS_MUSIC                             = 06h
        ram:0e1f 9d 51           dw         AFTER_ENTER_INITIALS_MUSIC                       = 06h
        ram:0e21 82 52           dw         INTRO_MUSIC                                      30
        ram:0e23 48 54           dw         GAME_OVER_MUSIC                                  = 06h
        ram:0e25 13 55           dw         SUCCESSFULLY_FINISH_LEVEL_MUSIC                  = 06h
        ram:0e27 fa 55           dw         FINISH_LEVEL_8_MUSIC                             = 06h
        ram:0e29 a4 5e           dw         CONTINUE_MUSIC                                   = 06h
        ram:0e2b 51 60           dw         MAYBE_PERFECT_BONUS_MUSIC                        = 06h
        ram:0e2d d2 60           dw         UNKNOWN_FANFARE_MUSIC                            = 06h
        ram:0e2f 6d 61           dw         UNKNOWN_FANFARE_MUSIC_02                         = 06h
        ram:0e31 04 ff           dw         FF04h                                            38 stops music playing
        ram:0e33 36 62           dw         UNKNOWN_FANFARE_MUSIC_03                         = 06h
        ram:0e35 5c 18           dw         FLAIL_HIT_SOUND                                  = 88h
        ram:0e37 86 18           dw         FALLING_SOUND                                    = C1h
        ram:0e39 9c 18           dw         BOUNCING_SOUND_(LOOPS)                           = C1h
        ram:0e3b c9 18           dw         OLD_MAN_TALKING_SOUND                            = C8h
        ram:0e3d 57 19           dw         OLD_MAN_TALKING_SOUND_02                         = C8h
        ram:0e3f a9 19           dw         DRAGON_DIE_SOUND                                 = 90h
        ram:0e41 90 1a           dw         MAYBE_BLOCK_BOUNCE_UP_SOUND                      40
        ram:0e43 ba 1a           dw         FALLING_SOUND_02                                 = C8h
        ram:0e45 d0 1a           dw         BOSS_HIT_SOUND                                   = C8h
        ram:0e47 e6 1a           dw         DRAGON_SPEW_FIRE_SOUND                           43 might be the last sound

[jotd]

you've not chosen the simplest game to remake. Good luck. And nice work so far.

[chadderack]

Originally Posted by jotd

you've not chosen the simplest game to remake. Good luck. And nice work so far.

Thanks.

Little update ... seems the sprite drawing routine (in z80 opcodes) isn't even being emulated by MAME. I've been looking all over for it.

Seems MAME does its own sprite drawing routine for some machines, I guess, because it is emulating some sort of hardware that will immediately blit directly to the screen. So I've been running through the MAME debugger looking for something that was never there.

The gfx1-gfx3 roms (holding all of the graphics) are never directly referenced (it seems) by the maincpu code, which makes sense. They probably have the motherboard wired to check a vector on some address (In Black Tiger it might be E140 and E142) which then would cause a routine to read from the gfx chips directly to the screen.

The reason I was able to pick up changes to the screen in the debugger was that drawing text and drawing backgrounds DOES seem to be emulated fully by MAME... meaning that the original opcodes on the Z80 maincpu are run and emulated, which seems to have the effect of loading tile maps and text.
The same isn't true for the sprites, which seem to not be emulated (for the reason explained above).

The only real problem this presents is that I can't tell exactly what Z80 code puts the player on screen, for example. On a real Black Tiger machine, the maincpu probably puts a vector in the TILE/SPRITE queue (at E100) and then the hardware (with the motherboard configured as I explained) takes over.

I may not be able to find functions in the Z80 code using the sprites. The sounds, however, have given me quite a lot of the labels for the functions. I can probably fully reverse the source.

[lmimmfn]

I would be very surprised if the emulation is not referencing the sprites somewhere(as it loads the roms) as the z80 needs both initialize the HW with sprite locations and to tell the HW to move them, maybe taking 2 snapshots 1 second apart and doing a diff on the hex might reveal something?

As you say, the gfx chip(s) might just be reading from a memory location and updating accordingly but still needing updates to those values by Z80.

[chadderack]

Originally Posted by lmimmfn

I would be very surprised if the emulation is not referencing the sprites somewhere(as it loads the roms) as the z80 needs both initialize the HW with sprite locations and to tell the HW to move them, maybe taking 2 snapshots 1 second apart and doing a diff on the hex might reveal something?

As you say, the gfx chip(s) might just be reading from a memory location and updating accordingly but still needing updates to those values by Z80.

Seems the sprite blitting is actually done in MAME and not by emulated Z80 code.

I just checked through the entire MAME source and found:

https://github.com/mamedev/mame/blob...o/blktiger.cpp

(previously I was just looking at ~/driver/blktiger.cpp)

This shows how the sprite structures are read.
Seems they live at $FE00 ~ $FFFF in RAM.

When MAME emulates the vertical blank (high), it redraws the screen and this is how the screen is structured (in 4 layers)

	bitmap.fill(1023, cliprect);

	if (m_bgon)
		(m_screen_layout ? m_bg_tilemap8x4 : m_bg_tilemap4x8)->draw(screen, bitmap, cliprect, TILEMAP_DRAW_LAYER1, 0);

	if (m_objon)
		draw_sprites(bitmap, cliprect);

	if (m_bgon)
		(m_screen_layout ? m_bg_tilemap8x4 : m_bg_tilemap4x8)->draw(screen, bitmap, cliprect, TILEMAP_DRAW_LAYER0, 0);

	if (m_chon)
		m_tx_tilemap->draw(screen, bitmap, cliprect, 0, 0);

Shows that background is drawn first, then sprites, then more tiles (for items the player can walk behind) and then the text layer (for the HUD).

The background and text are directly updated by the emulated Z80 code. Sprites are being done in MAME, indirectly replacing whatever hardware (soldering/etc) on the Black Tiger motherboard.

It does help a bit in describing the 4-byte structures that describe each sprite. However I'm not sure how the gfx emulator loads the Black Tiger sprite roms.

Since I'm not re-implementing sprites the way Black Tiger (arcade) does, it doesn't matter. What does matter (for reversing the game logic) is knowing what sprite data structures will draw what on the screen. Then I can label the structures as "player sprite data" and so forth.

It looks like this:

SPRITE STRUCTURE (in Z80 src code):

Byte 0  |  Byte 1  |  Byte 2  |  Byte 3
-----------------------------------------
(tile/sp)   attrib       y pos      x pos
index

attrib = palette = bits 0-2; flip tile (sprite piece) horiz = bit 3

attrib bit 4 =>      if set, subtract 256 from x pos
attrib bits 5-7 => index |=( (attrib & E0) << 3)

[chadderack]

Ok, now we're getting somewhere.

Now that I understand how sprites work, I was able to use the sprite ram area to put four sprite structures together like this:

INDEX/ATTR/Y/X

03 08 10 00              ; upper body. attr =8 => flipped tile
02 08 10 10              ; upper body. attr =8 => flipped tile, 16 (10h) pixels to the right
0b 08 20 00              ; lower body. attr =8 => flipped tile; 16 (10h) pixels down from upper body
0a 08 20 10              ; lower body. attr =8 => flipped tile; 16 (10h) pixels down from upper body, 16 (10h) pixels to the right

And came up with the result (attached)



Again, I won't use this scheme on the Amiga hardware; I'm just going to use this understanding to reverse engineer the existing code (find data structures, which will help naming all of the functions).

[lmimmfn]

Excellent, great work
Quite enjoying reading the progress analysing from arcade roms with MAME

[dlfrsilver]

Originally Posted by chadderack

Ok, now we're getting somewhere.

Now that I understand how sprites work, I was able to use the sprite ram area to put four sprite structures together like this:

INDEX/ATTR/Y/X

03 08 10 00              ; upper body. attr =8 => flipped tile
02 08 10 10              ; upper body. attr =8 => flipped tile, 16 (10h) pixels to the right
0b 08 20 00              ; lower body. attr =8 => flipped tile; 16 (10h) pixels down from upper body
0a 08 20 10              ; lower body. attr =8 => flipped tile; 16 (10h) pixels down from upper body, 16 (10h) pixels to the right

And came up with the result (attached)

Attachment 72783

Again, I won't use this scheme on the Amiga hardware; I'm just going to use this understanding to reverse engineer the existing code (find data structures, which will help naming all of the functions).

Brilliant job. I did the same thing for Final Fight AGA, i crawled inside the arcade program to get sprites metadata, by luck, it seems easier on Black Tiger. Final Fight has the Sprite moving/attacking/defensing IA seperated.

[chadderack]

Originally Posted by lmimmfn

Excellent, great work
Quite enjoying reading the progress analysing from arcade roms with MAME

Originally Posted by dlfrsilver

Brilliant job.

Thanks guys

I did the same thing for Final Fight AGA, i crawled inside the arcade program to get sprites metadata, by luck, it seems easier on Black Tiger. Final Fight has the Sprite moving/attacking/defensing IA seperated.

Yeah, you just have to figure out the scheme and have some patience

...

This is what I'm able to do right now... finding all of the player animations. Labeling those should help labeling the functions where they are referenced. Still a bit of work to do.

                             PLAYER_ANIMATION_OFFSET_TABLE_02+1              XREF[2,1]:   FUN_Bank08__8126:81fa(*), 
                             PLAYER_ANIMATION_OFFSET_TABLE_02                             FUN_Bank08__8126:820c(R), 
                                                                                          FUN_Bank08__8126:820e(R)  
    Bank08::9698 ac 96           dw         PLAYER_LEVEL_1_NO_ARMOR_WALKING_AND_KNEELING_T   = 9730h
    Bank08::969a b8 96           dw         PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_TABLE_01        = 97F0h
    Bank08::969c c4 96           dw         WORD_Bank08__96c4                                = 98B0h
    Bank08::969e d0 96           dw         WORD_Bank08__96d0                                = 9970h
    Bank08::96a0 e8 96           dw         WORD_Bank08__96e8                                = 99D0h
    Bank08::96a2 dc 96           dw         WORD_Bank08__96dc                                = 9A30h
    Bank08::96a4 f4 96           dw         WORD_Bank08__96f4                                = 9A90h
    Bank08::96a6 00 97           dw         WORD_Bank08__9700                                = 9B20h
    Bank08::96a8 0c 97           dw         WORD_Bank08__970c                                = 9B80h
    Bank08::96aa 18 97           dw         WORD_Bank08__9718                                = 9BE0h
                             PLAYER_LEVEL_1_NO_ARMOR_WALKING_AND_KNEELING_T  XREF[1]:     Bank08::9698(*)  
    Bank08::96ac 30 97           dw         PLAYER_LEVEL_1_NO_ARMOR_WALKING_RIGHT            = C6h
    Bank08::96ae 60 97           dw         PLAYER_LEVEL_1_NO_ARMOR_CROUCHING_RIGHT          = B2h
    Bank08::96b0 90 97           dw         PLAYER_LEVEL_1_NO_ARMOR_CROUCHING_LEFT           = B2h
    Bank08::96b2 90 97           dw         PLAYER_LEVEL_1_NO_ARMOR_CROUCHING_LEFT           = B2h
    Bank08::96b4 c0 97           dw         PLAYER_LEVEL_1_NO_ARMOR_WALKING_LEFT             = C6h
    Bank08::96b6 90 97           dw         PLAYER_LEVEL_1_NO_ARMOR_CROUCHING_LEFT           = B2h
                             PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_TABLE_01       XREF[1]:     Bank08::969a(*)  
    Bank08::96b8 f0 97           dw         PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_RIGHT_POS_1     = D2h
    Bank08::96ba 20 98           dw         PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_CROUCH_RIGHT_01 = B4h
    Bank08::96bc 50 98           dw         PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_CROUCH_LEFT_01  = B4h
    Bank08::96be 50 98           dw         PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_CROUCH_LEFT_01  = B4h
    Bank08::96c0 80 98           dw         PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_LEFT_POS_1      = D2h
    Bank08::96c2 50 98           dw         PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_CROUCH_LEFT_01  = B4h

[dlfrsilver]

Originally Posted by chadderack

Thanks guys



Yeah, you just have to figure out the scheme and have some patience

...

This is what I'm able to do right now... finding all of the player animations. Labeling those should help labeling the functions where they are referenced. Still a bit of work to do.

                             PLAYER_ANIMATION_OFFSET_TABLE_02+1              XREF[2,1]:   FUN_Bank08__8126:81fa(*), 
                             PLAYER_ANIMATION_OFFSET_TABLE_02                             FUN_Bank08__8126:820c(R), 
                                                                                          FUN_Bank08__8126:820e(R)  
    Bank08::9698 ac 96           dw         PLAYER_LEVEL_1_NO_ARMOR_WALKING_AND_KNEELING_T   = 9730h
    Bank08::969a b8 96           dw         PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_TABLE_01        = 97F0h
    Bank08::969c c4 96           dw         WORD_Bank08__96c4                                = 98B0h
    Bank08::969e d0 96           dw         WORD_Bank08__96d0                                = 9970h
    Bank08::96a0 e8 96           dw         WORD_Bank08__96e8                                = 99D0h
    Bank08::96a2 dc 96           dw         WORD_Bank08__96dc                                = 9A30h
    Bank08::96a4 f4 96           dw         WORD_Bank08__96f4                                = 9A90h
    Bank08::96a6 00 97           dw         WORD_Bank08__9700                                = 9B20h
    Bank08::96a8 0c 97           dw         WORD_Bank08__970c                                = 9B80h
    Bank08::96aa 18 97           dw         WORD_Bank08__9718                                = 9BE0h
                             PLAYER_LEVEL_1_NO_ARMOR_WALKING_AND_KNEELING_T  XREF[1]:     Bank08::9698(*)  
    Bank08::96ac 30 97           dw         PLAYER_LEVEL_1_NO_ARMOR_WALKING_RIGHT            = C6h
    Bank08::96ae 60 97           dw         PLAYER_LEVEL_1_NO_ARMOR_CROUCHING_RIGHT          = B2h
    Bank08::96b0 90 97           dw         PLAYER_LEVEL_1_NO_ARMOR_CROUCHING_LEFT           = B2h
    Bank08::96b2 90 97           dw         PLAYER_LEVEL_1_NO_ARMOR_CROUCHING_LEFT           = B2h
    Bank08::96b4 c0 97           dw         PLAYER_LEVEL_1_NO_ARMOR_WALKING_LEFT             = C6h
    Bank08::96b6 90 97           dw         PLAYER_LEVEL_1_NO_ARMOR_CROUCHING_LEFT           = B2h
                             PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_TABLE_01       XREF[1]:     Bank08::969a(*)  
    Bank08::96b8 f0 97           dw         PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_RIGHT_POS_1     = D2h
    Bank08::96ba 20 98           dw         PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_CROUCH_RIGHT_01 = B4h
    Bank08::96bc 50 98           dw         PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_CROUCH_LEFT_01  = B4h
    Bank08::96be 50 98           dw         PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_CROUCH_LEFT_01  = B4h
    Bank08::96c0 80 98           dw         PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_LEFT_POS_1      = D2h
    Bank08::96c2 50 98           dw         PLAYER_LEVEL_1_NO_ARMOR_FIGHTING_CROUCH_LEFT_01  = B4h

Awesome. I have one hope : that you will release BT ressourcing assembly, even in z80 as an example for coders who would want to get ideas as well to make a new game in term of logic. Japanese coders did wonders in their games.

[lmimmfn]

Originally Posted by dlfrsilver

Awesome. I have one hope : that you will release BT ressourcing assembly, even in z80 as an example for coders who would want to get ideas as well to make a new game in term of logic. Japanese coders did wonders in their games.

Yes, that would be cool, based on the Arcade hardware it could help with proper Amiga versions of 1943, Side Arms, Commando etc.

[dlfrsilver]

Originally Posted by lmimmfn

Yes, that would be cool, based on the Arcade hardware it could help with proper Amiga versions of 1943, Side Arms, Commando etc.

Yes, you read in my mind.

Side Arms comes to my mind first, and yes then 1943.

[lmimmfn]

Not sure if useful or not and maybe you already checked it, but the cheat XML for blacktiger shows the memory addresses for level select, infinite time etc.
Setting watchpoints on the addresses should provide some useful info.

Format of xml is described @ http://www.mamecheat.co.uk/forums/viewtopic.php?t=3768
i.e.

maincpu = The address space that the address exists in. "maincpu" is the most commonly wanted, but as seen above, not always.
p = Type of memory. p=RAM, m=ROM, o=ROM ??? ROM cheats aren't my thing, but p is usually what you want.
b = Width of value being plugged. b=byte (0x00), w=word (0x0000), d=double (0x00000000), q=quad (0x0000000000000000)
FF022F = Address. Have fun with Midway machines. They use a very unusual system which I don't like much.
99 = The value being plugged in. (Hexidecimal)

<mamecheat version="1">

  <cheat desc="Infinite Lives">
    <script state="run">
      <action>maincpu.pb@F3A0=09</action>
    </script>
  </cheat>

  <cheat desc="Infinite Time">
    <script state="run">
      <action>maincpu.pb@F3B1=3B</action>
    </script>
  </cheat>

  <cheat desc="Infinite Shield">
    <script state="run">
      <action>maincpu.pb@F3AD=06</action>
    </script>
  </cheat>

  <cheat desc="Infinite Money">
    <script state="run">
      <action>maincpu.pb@F3A8=FF</action>
    </script>
  </cheat>

  <cheat desc="Infinite Potions">
    <script state="run">
      <action>maincpu.pb@F3B0=09</action>
    </script>
  </cheat>

  <cheat desc="Infinite Keys">
    <script state="run">
      <action>maincpu.pb@F3AB=09</action>
    </script>
  </cheat>

  <cheat desc="Invincibility"> <comment>Falling down holes kills!</comment>
    <script state="run">
      <action>maincpu.pb@E905=01</action>
      <action>maincpu.pb@F424=0F</action>
    </script>
  </cheat>

  <cheat desc="Always have the Best weapon">
    <script state="run">
      <action>maincpu.pb@F3AC=04</action>
    </script>
  </cheat>

  <cheat desc="Select starting level">
    <parameter min="1" max="8" step="1"/>
    <script state="run">
      <action condition="(maincpu.pb@F3A1==00)">maincpu.pb@F3A1=(param-1)</action>
    </script>
  </cheat>

</mamecheat>
<!-- Cheat file downloaded from http://www.mamecheat.co.uk, see cheat.txt for list of contributors. -->

Originally Posted by dlfrsilver

Yes, you read in my mind.

Side Arms comes to my mind first, and yes then 1943.

exactly, loved Side Arms in the Arcade, only saw the Amiga version recently, . Capcom arcade games are brilliant, its such a shame US Gold ported most of them, especially Tiertex

[chadderack]

Originally Posted by lmimmfn

Not sure if useful or not and maybe you already checked it, but the cheat XML for blacktiger shows the memory addresses for level select, infinite time etc.

Cool, I'll add that stuff when I stumble upon it
Cheers!

ETA: Actually I have some of those variables mapped already... and they check out. I wasn't aware of a couple of them, but I'll add their labels to the Ghidra project.

[lmimmfn]

Originally Posted by chadderack

Cool, I'll add that stuff when I stumble upon it
Cheers!

ETA: Actually I have some of those variables mapped already... and they check out. I wasn't aware of a couple of them, but I'll add their labels to the Ghidra project.

No problem at all, glad to help

[chadderack]

For those wanting an extended explanation of my process (so more Z80 based arcade games can be ported) at some point I'll try to do a mcgeezer or Photon of Scoopex type YouTube series to explain how to reverse those ROMs using Ghidra and other tools. (This will probably be down the road a bit)

...

A lot of good progress; but I've got a lot to do. I'm not stuck at all in terms of finding structures and labeling things.

Here's a sampling of what I've done lately. This is for the demon character (the Level 4 boss, not the guy who throws fire)

It's all about labeling things, then going back and finding reference to those labels and thinking about what the function might do. When you see the "Maybe_" prefix on a function name, it's a guess. Once I step through the code or it becomes obvious, I remove the prefix

For this llsting, you see clusters of 5 bytes. These describe an animation frame. I believe the first value is a duration value (ex: 4). The rest of the values are definitely the (first) sprite tile index (in the sprite), the attribute (including palette and 3 msbs of the tile index), the x offset and the y offset.

So 04, 6a, aa, 00, fd means:

Keep this frame on screen for 4 vertical blanks
Tile 6a + (a0 from attr)
Palette 2 (from aa)
Reversed (aa & 0x8) -- so the demon is facing right, not left
delta x=0 (keep x value)
delta y=fd (-3... move up 3 pixels for this frame)

A series of animation frames like this provide a sequence.
Roughly (sprite IDs): a6 -> b0 -> b2 -> b0 -> a6 -> b0 -> b2 -> b0 (etc)

The sequence seems to describe the character flapping his wings and rising (not moving along X at all)

                             FLYING_DEMON_RIGHT_ANIMATION_03                 XREF[1]:     Maybe_HandleDemon:a069(*)  
    Bank02::a48a 04 a6 aa        dnw_char                                                    if 0, ks death animation. If FF,
                 00 fd
    Bank02::a48f 04 b0 aa        dnw_char                                                    if 0, ks death animation. If FF,
                 00 fd
    Bank02::a494 04 b2 aa        dnw_char                                                    if 0, ks death animation. If FF,
                 00 fd
    Bank02::a499 04 b0 aa        dnw_char                                                    if 0, ks death animation. If FF,
                 00 fd
    Bank02::a49e 04 a6 aa        dnw_char                                                    if 0, ks death animation. If FF,
                 00 fd
    Bank02::a4a3 04 b0 aa        dnw_char                                                    if 0, ks death animation. If FF,
                 00 fd
    Bank02::a4a8 04 b2 aa        dnw_char                                                    if 0, ks death animation. If FF,
                 00 fd
    Bank02::a4ad 04 b0 aa        dnw_char                                                    if 0, ks death animation. If FF,
                 00 fd
    Bank02::a4b2 04 a6 aa        dnw_char                                                    if 0, ks death animation. If FF,
                 00 fd
    Bank02::a4b7 00              ??         00h
    Bank02::a4b8 4b a0           dw         Maybe_HandleDemon
                             FLYING_DEMON_ANIMATION_TABLE_01+1               XREF[2,1]:   FUN_Bank02__a0a9:a0d5(*), 
                             FLYING_DEMON_ANIMATION_TABLE_01                              FUN_Bank02__a0a9:a0d9(R), 
                                                                                          FUN_Bank02__a0a9:a0db(R)  
    Bank02::a4ba da a4           dw         dnw_character_anim_frame_Bank02__a4da            =

[dlfrsilver]

I'm sure now that capcom used a tool able to animate the sprite visually on screen, and then save the whole pattern as an array for use in game. Like a computerized puppet theater.

[saimon69]

Originally Posted by dlfrsilver

I'm sure now that capcom used a tool able to animate the sprite visually on screen, and then save the whole pattern as an array for use in game. Like a computerized puppet theater.

We had a similar system for Powder where could group sprites, assign basic movement or even memorized patterns, so i confirm that might be possible

[lmimmfn]

Originally Posted by dlfrsilver

I'm sure now that capcom used a tool able to animate the sprite visually on screen, and then save the whole pattern as an array for use in game. Like a computerized puppet theater.

For sure all these arcades are pattern related based on tools, the problem is figuring out the patterns, but it would be good to create tools(doesnt need to run on Amiga) to use these in a generic fashion and generate code/structures.

If it would help things i could easily write tools to use these patterns(if we know what they are) to generate some sort of Amiga compatable abstraction, essentially a transformation layer if possible.

[chadderack]

The thing about this is discovering any pattern.

Some of the data structures have function pointers embedded in them.

I just found the orange dragon (level 6?) and there's a ton of frames and information. Each dragon seems to have two entire tile blocks to itself. 2 of the 8 that are used for sprites are just the three dragons (Level 3, Level 6, Level 8) (with the different palettes). One quarter of the sprite tiles are dragon!

It's quite possible that the structure layout for each game is different (and even each sprite).

Have patience; we're going to get to the higher-level language brick by brick