Hi!... My name is Roberto Fresca, and I'm part of the MAME Dev Team since 1998. Here you can find some technical things about rare hardware, and some of my work in progress about emulation. This site is also intended to avoid duplicated efforts. This page is *always* in construction... :-)
--- 2021/02/16 23:15 ---
Happy New Year!!!... This time is not Psycho II, but it has some similarities. :-)
After more than 22 years avoiding us... WE HAVE MS.PACMAN TWIN PRESERVED AND EMULATED!!!
The board is a regular bootleg pacman hardware, with a daughterboard replacing the CPU, handling different things, as modify hardware parameters, offsets,
and a complex encryption scheme for the program.
Here are some details of the daughterboard...
This little monster has a custom DIL40 IC that handle the encryption. Addressing and data lines, as well as opcodes/data (through handling the /M1 line) are involved.
Anyway... Just teamed up with Mirko Buffoni to break the encryption and get the game working. We also got the invaluable help of ArcadeHacker & recreativas.org, who tested the real hardware exhaustively to get some responses. After a lot of work, we finally got the game working properly, with all its multiplexed controls. :)))
I will upload the whole story to the section "MS.PACMAN TWIN" soon... Here, some snaps:
Special thanks to ytsejam, that bought the board!
If you want to see more about the game, Haze made a nice video analyzing some tits and bits.
The title effect can't be appreciated due to the 30fps nature of the YouTube video.
Another happy end!!! :-)
--- 2021/02/14 22:15 ---
--- 2019/07/31 16:08 ---
As usual, I'm amazed about the good work Team Europe is doing getting and dumping a lot of rare boards. This time they got an original Victor 5 from Subsino.
The set supported in MAME, is a rare hack with the title 'G.E.A.', and also lacks of the samples sounds ROMs. This is the original game from Subsino / Buffy,
and the dump is complete, so I hooked the OKI 6295 to get the speech sounds in both games: This original, that now is the parent set, and the former one.
They also sent a complete dump of Victor 21, that always lacked the speech samples ROMS and now is complete.
With these new dumps, the color PROM of Victor 5 is confirmed to be good.
--- 2019/07/30 20:28 ---
Some weeks ago Team Europe dumped another original board from PM/BECK. The game was identified as Casino Poker, and added by Ivan as not working.
After take a close look, just discovered pieces of code using undocumented opcodes. Even ones that aren't present in any stock 6502.
Some of them turn the routines to execute something with a total lack of sense.
Code like:
7B86: A2 00 ldx #$00 ;load X register with 00.
7B88: 74 00 nop $00,x ;nop with extra argument.
7B8A: 9E 00 02 shx $0200,y ;AND with the high byte of the argument + 1
7B8D: 9E 00 03 shx $0300,y ;AND with the high byte of the argument + 1
7B90: E8 inx ;increments X register.
7B91: D0 F5 bne $7B88 ;loops...
7B93: 20 EA 78 jsr $78EA
...And...
4850: 9E 00 02 shx $0200,y ;AND with the high byte of the argument + 1
4853: 9E 01 02 shx $0201,y ;AND with the high byte of the argument + 1
4856: 9E 02 02 shx $0202,y ;AND with the high byte of the argument + 1
4859: 60 rts ;return from subroutine.
...There are other pieces of code that play with more of these undocumented non stock opcodes. Tired, asked Team Europe to remove the CPU sticker, and the device has not marks at all. Completely custom... DAMN!
So tried other CPUs from the family to get the extended set of opcodes and check what the hell they do... After an exhaustive analysis discarding things and playing with bits, pits, and tits (the BIT instructions also compromised the code), finally got the correct device: A Rockwell R65C02. This one runs the code with total sense. Now the above mentioned code turns to:
7B86: A2 00 ldx #$00 ;load X register with 00.
7B88: 74 00 stz $00,x ;clean the zero page.
7B8A: 9E 00 02 stz $0200,y ;clean $200 onward, indexed in X.
7B8D: 9E 00 03 stz $0300,y ;clean $300 onward, indexed in X.
7B90: E8 inx ;increments X register.
7B91: D0 F5 bne $7B88 ;loops...
7B93: 20 EA 78 jsr $78EA
...That has total sense.
Well... The conclusion: The game finally is Casino Poker, from 1988, PM / Beck Elektronik. Ver PM88-01-21. Now it's the new parent.
- CPU has no marks to avoid recognizement. Was identified as Rockwell R65C02, after exhaustive code analysis.
- The program has some protection things, as routines using extra undocumented opcodes to hang the program if it's running in a hardware based on a stock 6502 CPU.
- Graphics are different from the other Casino Poker sets, and looks really nice.
Also Bipolar PROM contents is different from the common in this kind of games. The game uses a banked palette to get green or blue background using each half of the palette. Here some snaps with both BG colors.
The default background color need to be checked against the real PCB. The blue background looks better for me.
Another happy end. The game is preserved and working properly. :-)
--- 2019/07/29 04:22 ---
Another day in the Paradise...
My friend from Team Europe got and dumped another rare board.
Damn thing!... The only thing to identify it's a sticker with the brand 'Paradais' and some sort of japanese words. It has a scratched surface CPU to avoid recognizement (now identified as 6502), 2x Toshiba HD46821P (PIA) for I/O, 1x GI AY-3-8910 for sounds and ports (both DIP switches banks are tied there), and 1x CIC8645BE as CRT controller.
Also you can see some 'engrish' issues here (reminds me the 'amuesment' from the The Boat title)...
...and here:
As soon as I started the emulation work, noticed that the program was scrambled in segments. Once figured it out, got proper RESET, IRQ and NMI vectors, plus a nice start with subroutines initializing both PIAs and the CRTC. Once mapped these devices and RAM, started the program, But... was not the expected thing...
After more analysis to the whole code, find that this piece of code was made just to warn the operators that they can't run this program in Golden Poker boards, since all devices accesses were mapped in the standard Golden Poker board addresses/offsets.Grull Osgo joined me on this quest. Found the REAL program start, descramble the segments, and mapped the devices accordingly to get the game preliminarily running. The first impression was not so good...
But after more work on the graphics banks and trying different ways to bank the graphics, started to get better results...
Graphics banks are looking correct, but the color system was not even close. So, made some improvements to GFX bank 0 (chars) colors...
But even when we had better colors, these weren't correct. Even for GFX bank 1 (cards). So discovered better colors combinations re-arranging the graphics bitplanes and displacing the palette to match some cards, that washed out the punk green style from the Jacks, Queens, and Kings hair, bringing them back to the 'Royal Classics'...
And even improving more the GFX bank 0 to match the internal hearts/diamonds to red, and clubs/spades to black.
But... still both were wrong and the title really sucks!!.
So discovered that the needed colors groups were located in the palette at even places, discarding the odds.
That made me think that the three lines used in the Attr RAM for colors should be shifted left once to get the proper colors for these banks. So, from 0111-0000 >> 4, to: 0111-0000 >> 3, getting the code location x2.
About the three bipolar PROMS, the game use one palette for each GFX bank, and the last one (GFX bank 3, title tiles) through RGB direct. Another thing was the amount of work to reconstruct the video hardware, construct inputs/DSW from the scratch, and get the game in working state.
Here are some pics of the final approach!
Colors need to be checked against the real board to be sure they match at all...
--- 2019/07/11 00:55 ---
The Boat...
Yes!!... The Boat. It's a rare amusement/gambling game from 1987. It's in fact a horse race, but with boats instead of horses.
Team Europe got the hardware and dumped the devices, AJR started a preliminary driver, and I added some work to get the game partially working. There are unresolved multiplexion issues, as missing selectors to demux these inputs. But at least with a partial set of bet buttons you can play the game... Here some snaps:
And here a little video with the attract running plus two boat races played...
--- 2019/06/20 17:14 ---
New set chips for Aristocrat MkV...
After a lot of efforts trying to find these missing set chips, finally got them, dumped and got them working.
These are... Aristocrat MkV Set Chip v01:
Aristocrat MkV Set Chip v04.03.07:
Aristocrat MkV Set Chip v04.04.05:
--- 2019/04-2019/05 ---
Bunch of new stuff from Team Europe...
More dumps from Team europe!!!... A lot of vintage rare games were purchased by Team Europe. I was working so hard emulating these games and adding them to MAME. Here, you can see some snaps of the games in working state.
Another rare version of Potten's Poker with German language:
A new Royal Card game on Nichibutsu blitter hardware from 1982, with Z80 CPU and a AY-3-8910 for sound:
Super Mini Boy, from Bonanza Enterprises. Multi game on a complex M6502 hardware (with lots of obfuscations, tricks and multiplexions), with the following games:- POKER.
- GOLDEN FRUITS.
- BLACK JACK.
- HI-LO.
- BACCARAT.
--- 2019/04/18 04:02 ---
Royal Card, from Evona Electronic...
Another game that was waiting for years. :))
This platform is based on Multi Win game, and it's highly encrypted. Again, thanks to Andreas Naive's superb work we have the game program unencrypted (still need to check some suspicious routines, but we strongly think that all the issues hopely will be figured out soon).
Again, with Grull Osgo, started to work on this rare game weeks ago. We improved the emulation doing a lot of things: Reworked the memory map, mirrored the PIA devices, modified the encryption range, reworked inputs (still need some work), and much more. Still need more reverse-engineering, due to some weird/nonsense routines, and interrupts collision/troubles.
The game has Polish language instead of Slovak, so language in the game description will also change. Here you can see some snaps of the game working...
One curious thing: The game has graphics tiles for an alternative Evona Electronic logo with the Marilyn Monroe face, but seems unused.
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