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iq_132's Neo Geo ports

iq_132

iq_132

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I figured I should just create a post specifically talking about my ports to Neo Geo and their statuses.

1. Cabal
- There are some graphics artifacts that are still present (scanline flicker)


2. Nichibutsu's Terra Cresta
- One remaining bug with high score entry
- Needs tested on real hardware
View: https://www.youtube.com/watch?v=WDsuOHou5Yw


3. Nichibutsu's Soldier Girl Amazon
- One remaining bug with enemy shot speed
- Needs tested on real hardware
View: https://www.youtube.com/watch?v=bsl80VVRhjk


4. Nichibutsu's Kid no Hore Hore Daisakusen (Booby Kids)
- Needs tested on real hardware
View: https://www.youtube.com/watch?v=R8KPtDE4U9w


I've also been asked by a few people to start a Patreon, I've resisted in the past, but I could use some help purchasing some hardware for testing/developing.
https://www.patreon.com/iq_132
 
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@iq_132 sir , in Cabal , i played 3 or 4 stages and in stage 3&4 also some parts of graphics from screen are missing !
I'm using .neo in MiSTer to play it ! Maybe it happened only me !
Anyway is very playable for me :happy:
 

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If you need someone to test on real hardware, I'd love to do it :)
 
I've had multiple people looking at the Cabal rom now, including Ozzy (who is the developer of TEOT Tsunami Edition) and the creator of the neosdconv tool, and we think there is just something non-standard about the rom files (they don't run in AES mode for example) preventing the .neo file from booting on a NeoSD. We've determined that the .neo conversion process is working well with anything else we can throw at it.

If anyone has any ideas for making the roms more compliant, I'd appreciate it, because I'd love to help test on multiple revisions of real MVS and AES hardware.
 
Yes, I suspect the way I am starting the game is the issue for the NeoSD. I hook into the vblank interrupt and take over the 68k as soon as it switches from the bios' vector table and starts using the game's vector table. I have not been able to get the standard jump table way to work for any of my ports. Here's a pseudo-code snippet of what I'm doing.
Code: 
_vblank_callback
    ori     #$2700, SR               ; first item in vblank
    clr.b   $300001                ; kick watchdog
    move.w  #$7, $3c000c.l                 ; ack irq
    cmpi.b  #$1, $10d2ff            ; have we gone through init process?
    bne.s     _dont_use_game_vblank        ; no, jump to $122
    ; do game vblank here
 
Thanks for accepting me on this forum! I've tested Cabal on my MVS and it plays Great.
I'm curious if early SNK Games can be ported to MVS.
Gang Wars
Street Smart
POW
 
iq_132 said:
Those are likely do-able. They would take a considerable amount of work though. I've been shooting for the "low-hanging fruit" ones first.
Click to expand...
I'm assuming the pre-requisite is that the game uses a single 68000 Main CPU, and a Z80 + Yamaha YM2610 (or compatible) CPUs for Audio
beyond that though what makes a game more amicable to port than another?
 
twistedsymphony said:
I'm assuming the pre-requisite is that the game uses a single 68000 Main CPU, and a Z80 + Yamaha YM2610 (or compatible) CPUs for Audio
beyond that though what makes a game more amicable to port than another?
Click to expand...
Generally, here are my rules:
1. 68k-based
2. ram can't be in the $ff0000-$ffffff region.
2a. the 68k has a really funky way of handling accesses to this region and it can't easily
be changed.
3. sprites should be 16x16 or (16x any number less than 512) in tile size (can be smaller)
3a. sprites should be at most 4 bits per pixel
3b. there can be no more than ~380 sprites
4. background layer 16x16 in tile size preferred
4a. background layer must be drawn in sprites on the neogeo (1 sprite can be 16 pixels wide by 512 tall)
4b. background tiles should be no more than 4 bits per pixel
5. Screen resolution should be no larger than 320x224 - however there is "some" wiggle room with this
 
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To add a bit more detail to this, these are games that are likely possible:

Good candidates (note all of this information is gleaned from MAME):

Cabal - 99% done
- 68k-based
- ram is in 40000-43fff region
- sprites and background tiles are 16x16x4bpp
- maximum of 256 sprites
- backgrounds is 16x16 and does not scroll
- characters are 8x8
- resolution is 256x224

Terra Cresta - 90% done (will have to re-port this- lost sources!)
Soldier Girl Amazon - 90% done
Kid no Hore Hore Daisakusen - 90% done
- 68k-based
- ram is in 20000-23fff/40000-42fff region
- sprites and background tiles are 16x16x4bpp
- maximum of 64 sprites
- backgrounds are 64x32 tiles wide/high, but can be broken into two 32x32 maps or 4 16x32 maps
- characters are 8x8 tiles
- resolution is 256x224

Karnov - 65% done
Chelnov
- 68k-based
- ram is in 60000-63fff region (mostly)
- sprites and background tiles are 16x16x4bpp
- maximum of 256 sprites (actually uses 100)
- backgrounds are 32x32 tiles
- characters are 8x8
- 256x240 resolution - these have a higher resolution than the neogeo (vertically), but seem to keep
the player centered on the screen. Wonder Planet does not.

Toki
- 68k-based
- ram is in 60000-6ffff region
- sprites and background tiles are 16x16x4bpp
- maximum of 256 sprites
- backgrounds are 32x32 tiles x 2 layers -> this means 32x2 sprites necessary to replace (64)
- characters are 8x8 tiles
- 256x224 resolution

WWF Superstars
- 68k-based
- ram is in 1c0000 region
- sprites and background tiles are 16x16x4bpp
- maximum of (1024/2)/10 sprites
- background is 32x32 tiles
- characters are 8x8
- resolution is 256x240 - likely keeps action in the center

Prehisle - 10% done
- 68k-based
- ram is in 70000-73fff region (mostly)
- sprites and background tiles are 16x16x4pp
- maximum of 256 sprites
- backgrounds are very large, but can be broken up into manageable pieces
- characters are 8x8
- 256x224 resolution

Ginga NinkyouDen
- 68k-based
- ram is in 20000-5xxxx range
- sprites and background tiles are 16x16x4bpp
- maximum of 256 sprites
- backgrounds and foregrounds are large, but can be worked around
- characters are 8x8
- 256x224 resolution

Meijinsen
- 68k based
- ram is in 0x180000-181fff range
- is bitmap-based, but this may be workable
- 240x224 resolution

Alpha II / Alpha III / Alpha V
Time Soldiers
Sky Soldiers
Gold Medalist
Sky Adventure
Gang Wars
Super Champion Baseball
- 68k based
- ram is in 40000-40fff range
- tons of sprites, but very similar to neogeo
- sprites are 16x16x4bpp and there are no background tiles
- characters are 8x8
- resolution is 256x224
-- note this is likely a VERY complex port

SNK-68K
P.O.W.
Street Smart
Ikari III - The Rescue
SAR - Search and Rescue
- 68k-based
- ram is in 40000-43fff range
- sprites are 16x16x4bpp and there are no background tiles
- characters are 8x8
- resolution is 256x224
-- note this is likely a VERY complex port
 
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