JTCPS - FPGA Arcade Hardware

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Capcom System 1/1.5/2 compatible verilog core for FPGA by Jose Tejada (jotego).

Original Documentation

The internet archive holds some schematics related to this work.

Forgotten Worlds manual

Memory Requirements

All CPS1 and CPS1.5 operate correctly on a 32MB SDRAM system. Some CPS2 games may require a 64MB module. Those games are listed as having a GFX ROM of 16MB or more below. Please check the CPS2 ROM size section.

Control

MiSTer allows for gamepad redifinition. However, the keyboard can be used with more or less the same layout as MAME for MiST(er) platforms. Some important keys:

-F12 OSD menu -P Pause. Press 1P during pause to toggle the credits on and off -5,6 1P coin, 2P coin -1,2 1P, 2P

For MiST, the first 6 gamepad buttons are used for game buttons, the next 2 buttons are used for credit and start buttons. If there is still one button left in the gamepad, it will be used for pause.

There is an option to slow down the game (available only for CPS2). If you enable the 1P_hold_for_slow setting on the OSD, then while the 1P button is held the game will run at half the speed. Release the 1P button to go back to normal speed or disable the option in the OSD. Note that if the option is enabled the 2P, 3P and 4P buttons will also activate the slow down effect.

Setup

MiSTer

Copy the RBF file to _Arcade/cores and the MRA files to _Arcade. Copy zipped MAME romsets to _Arcade/mame. Enjoy.

It is also possible to keep the MAME romsets in _Arcade/mame but have the MRA files in _CPS and the RBF files in _CPS/cores

The rotate screen OSD option is ignored for horizontal games.

MiST

You need to generate the .rom file using this (tool)[https://github.com/sebdel/mra-tools-c/tree/master/release]. Basically call it like this:

mra ghouls.mra -z rompath -A

And that will produce the .rom file and a .arc file. The .arc file can be used to start the core and directly load the game rom file. Note that the RBF name must be JTCPS1.RBF for it to work. The three files must be in the root folder.

Important: make sure to have the latest firmware and latest version of the mra tool.

Copy the RBF, .arc and .rom files to MiST and enjoy!

Note that there is no screen rotation in MiST. Vertical games require you to turn your screen around. You can however flip the image through the OSD.

Pang! 3 and all CPS 1.5/2 games did not use DIP switches to configure the game, but a small non-volatile RAM. You have to enter the test menu to configure it (via OSD). After you have configured the settings, save the contents using the OSD option Save NVRAM. A file will be created at the root of your SD card called game.RAM, where game will match the name of the .ROM file used with the game.

Issues

Please report issues (here)[https://github.com/jotego/jtbin/issues].

QSound Hiss

The DSP16A clock enable must be an exact multiple of 30MHz. Otherwise the sampling period will not be constant, generating jitter. The effect of jitter is very obvious in the DAC used on MiST because when all sound goes silent an ugly transient occurs. That effect was not noticeable in MiSTer, which uses a different DAC.

Even with the right clock enable, there is still hiss occasionally in MiST(er). Using the FPGA logic analyzer I could check that the period was indeed constant but hiss was present.

CPS-1 Audio

The OKI PCM input clock is 1MHz, depending on the SS input setting, this gives two sampling frequencies:

SS	Fs (Hz)	4xFs	a	1-a
0	6097.5	24390	0.8200	0.1800
1	7575.7	30303	0.8524	0.1476

The original board has a first-order low pass filter at 770 Hz, this can be implemented with a first order IIR filter:

y[k] = a y[k-1] + (1-a) x[k]

where a = exp(-wc/T ) wc = 2pi770 = 4838 rad/s T = 1/4Fs

QSound

QSound requires its own firmware rom to work. In MAME this is called qsound.zip. QSound sampling frequency is 3746 ticks of the input clock, when the clock enable applied is 2/3. For a 90MHz input clock, this will result in the correct internal 30MHz and in a sampling frequency of 90MHz/3747=24,019.2Hz

The original board had a digitally controlled amplifier. The volume set on this amplifier could be read back by the CPU and DSP. In order to control the value read by these devices, press and hold the coin button for 1P while pressing up or down (for more or less volume). Note that this does not have an actual effect on the sound output.

PAL Dumps

PAL dumps cam be obtained from MAME rom sets directly. Use the tool jedutil in order to extract the equations from them. The device is usually a gal16v8. For instance:

jedutil -view wl24b.1a gal16v8

In order to see the equations for Willow's PAL.

Compilation

The core is compiled using jtcore from JTFRAME. Follow the instructions in the README file of (JTFRAME)[https://github.com/jotego/jtframe] and then:

source setprj.sh
jtcore cps1 -mister

This will produce the mister file.

Static Time Analysis (STA)

MiST and SiDi compilations produce STA clean files with the default seed. However the MiSTer RBF file with everything enabled doesn't always come STA clean. If you disable HDMI or sound during compilation the RBF file will normally be STA clean. Public binary distribution in jtbin are either STA clean or violations are below 99ps.

MRA Format

Offset	Length	Use
0 / 0o	2	Sound CPU ROM*
2 / 2o	2	PCM data*
4 / 4o	2	GFX ROM*
6 / 6o	2	QSound firmware*
10h / 20o	18	CPS-B configuration
22h / 42o	1	Game ID
23h / 43o	2	Bank offset
25h / 45o	2	Bank mask
27h / 47o	1	CPS-A board type (Pang! 3, etc.)
30h / 60o	11	Kabuki keys (CPS 1.5 only)
28h / 50o	1	CPS2 board type
2ch / 54o	20	CPS2 keys

All offset values are expressed in kilobytes and stored with MSB byte second

The offset for each graphic bank is comprised of two bytes. Each offset data is packed in 4 bits, with the MSB used for bank 3:

{ Offset_bank3, ..bank2, bank1, bank0 } = { byte 24h, byte 23h }

The 4-bit offset makes the MSB of the 20-bit GFX ROM address.

CPS-A board type format:

Bits	Use
0	CPU speed. 0=10MHz, 1=12MHz
3:1	Enables additional inputs on CPS-B chip side
4	High for charger games
5	0 = Disables Kabuki decryption

CPS2 board type format:

Bits	Use
1:0	Controller type

SDRAM Usage

CPS 1/CPS 1.5

SDRAM bank	Usage
0	RAM/VRAM/M68000 ROM
1	Sound CPU/PCM samples
2	GFX
3	GFX

CPS 1.5 ROM Size

The SDRAM layout is the same as for CPS 1. Although samples are much larger than in CPS 1 titles, they still fit in one SDRAM bank sharing space with the Z80 ROM.

Game	CPU	Z80	GFX	Q-Sound
Warriors of Fate	1 MB	128 kB	4 MB	2 MB
Cadillacs & Dinosaurs	1.5 MB	128 kB	4 MB	2 MB
The Punisher	1.5 MB	128 kB	4 MB	2 MB
S.N. Slam Masters	2.0 MB	128 kB	6 MB	4 MB
Muscle Bomber Duo	2.0 MB	128 kB	6 MB	4 MB

CPS 2 ROM Size

It looks like the 16kB memory add-on is not used for regular games. Maybe it is used for network connectivity only.

Game	CPU	Z80	GFX	Q-Sound	Obj base	Addon	Popularity
19XX	2.5 MB	128 kB	10 MB	4 MB	7080	No	191
1944	1.5 MB	128 kB	20 MB	8 MB	7080	No	161
Alien vs Predator	2.0 MB	128 kB	16 MB	4 MB	7000	No	637
Armored Warriors	4.0 MB	256 kB	20 MB	4 MB	7000	No	278
Battle Circuit	3.5 MB	256 kB	16 MB	4 MB	7080	No	87
Capcom Sports Club	2.5 MB	128 kB	8 MB	4 MB	7080	No	20
Cyberbots	4.0 MB	256 kB	32 MB	4 MB	7080	No	141
Darkstalkers	4.0 MB	256 kB	20 MB	4 MB	7080		146
Dimahoo	2.0 MB	256 kB	16 MB	8 MB	7080	No	32
DnD Shadow o. Mystara	4.0 MB	256 kB	24 MB	4 MB	7080	No	336
DnD Tower of Doom	2.5 MB	128 kB	12 MB	4 MB	7080	No	108
Eco Fighters	2.0 MB	128 kB	12 MB	4 MB	7000		64
Giga Wing	1.5 MB	128 kB	16 MB	8 MB	7080		66
Hyper SF II	4.0 MB	256 kB	32 MB	8 MB	7080		171
Janpai	1.0 MB	128 kB	16 MB	4 MB	7000		15
Jyangokushi	0.5 MB	128 kB	16 MB	4 MB			1
Mars Matrix	1.5 MB	128 kB	32 MB	8 MB		No	57
Marvel Super Heroes	4.0 MB	256 kB	32 MB	4 MB			165
Marvel vs SF	4.0 MB	256 kB	32 MB	8 MB			336
Marvel vs CAPCOM	4.0 MB	256 kB	32 MB	8 MB			377
Megaman 2	1.5 MB	256 kB	8 MB	4 MB			225
Darkstalker's revenge	4.0 MB	256 kB	32 MB	4 MB			54
Progear	1.0 MB	128 kB	16 MB	8 MB	7080	No	72
Puzz Loop 2	2.0 MB	128 kB	16 MB	4 MB	7000		16
Quiz Nanairo Dreams	2.0 MB	128 kB	8 MB	4 MB			8
Ring of Destruction	3.0 MB	256 kB	18 MB	4 MB			293
Slam Masters 2	3.0 MB	256 kB	18 MB	4 MB			291
SF alpha 1	2.0 MB	256 kB	8 MB	4 MB	7000		190
SF alpha 2	3.0 MB	256 kB	20 MB	4 MB	7000		218
SF alpha 3	4.0 MB	256 kB	32 MB	8 MB	7000		456
SF zero 2 alpha	3.0 MB	256 kB	20 MB	4 MB	7000		293
Super Gem Fighter	2.5 MB	256 kB	20 MB	8 MB			252
Super Puzzle Fighter 2	1.0 MB	256 kB	4 MB	4 MB	7000		210
SF2 New Challengers	2.5 MB	128 kB	12 MB	4 MB	7080	No	135
SF2 Turbo	3.5 MB	256 kB	16 MB	4 MB	7080		1200
Vampire Savior 1	4.0 MB	256 kB	32 MB	8 MB			30
Vampire Savior 2	4.0 MB	256 kB	32 MB	8 MB			26
X-Men Children of A.	4.0 MB	256 kB	32 MB	4 MB	7080	No	179
X-Men vs SF	3.5 MB	256 kB	32 MB	4 MB	7080	No	337

Simulation

Game

Generate a rom file using the MRA tool
Update the symbolic link rom.bin in ver/game to point to it
If all goes well, go.sh should update the sdram.hex file But if sdram.hex is a symbolic link to something else it might fail. You can delete sdram.hex first so it gets recreated

go.sh will fill up sdram.hex with zeros in order to avoid x's in simulation.
Apply patches if appropiate. The script apply_patches.sh can generate some alternative hex files which skip some of the test code of the game so it boots up more quickly
While simulation is running, it is possible to update the output video files by running raw2jpg.sh

Some Verilog macros:

FORCE_GRAY ignore palette and use a 4-bit gray scale for everything
REPORT_DELAY will print the average CPU delay at the end of each frame in system ticks (number of 48MHz clocks)
JTCPS_TURBO forces turbo mode, speeding up -slightly- the game speed, especially on boot-up

Video

Video only simulations can be done using mame dumps. Use the tool cfg2mame in the ver/video folder to create two .mame files that can invoked from mame to dump the simulation data. Run the game in debug mode but source from MAME the register file that cfg2mame creates. Then at the point of interest souce vram.mame. That creates the file vram.bin. Copy that file to a directory with the mame name of the game. Add a numerical index (see the other folders for examples). Create a hex file following the examples in the other files too. Now you run go.sh like this:

go.sh -g game -s number -frame 2

This will run the simulation for the folder game and looking for files with the number index. If you need to look at the sprites too, you need to run more than one frame as the object DMA needs a frame to fill in the data.

Support