Today Irem PAL update. We have a dump from PAL labeled ‘NIN-C-3F’ on a Ninja Spirit PCB, courtesy of ‘Robotype’.He also confirmed that this PAL is the same as the ‘MH-C-3F’ found on Mr.Heli as well as the ‘IF-C-3F’ on Image Fight is the same as the ‘TOM-C-3F’ on Legend of Hero Tonma
Last but not the least the PAL dumps from IREM M92 hardware present on our database are from a Gunforce PCB so they could not work for all M92 games.This has been confirmed by someone who tried them on a Ninja Baseball Batman PCB.So, testing of these PALs on different M92 games would be welcome and well accepted.
Back in January there was a discussion going on over on the Jamma+ forums regarding the D77-14 and D77-15 PAL dumps.
After a lot of help from various people and testing by myself here is the conclusion I have come to regarding this issue.
D77-14 is used when the main CPU ROM’s are 27c2001 (0x40000).
D77-15 is used when the main CPU ROM’s are 27c4001 (0x80000).
On a 27c2001 EPROM, pin 31 is the programming pin. It is active low so once the chip is programmed we want to keep this held high when in use. That’s exactly what the D77-14 PAL is doing. Pin 19 of this PAL is fixed HIGH and is connected to pin 31 of the 27c2001 EPROM.
On a 27c4001 EPROM, pin 31 not the programming pin but it is the upper most address bit and that’s why with a D77-15 pin 19 is able to toggle which allows for double sized EPROM’s to be used.
This is where the confusion comes in.
On many converted boards out there in the wild (and there is a lot of them) we have found there to be D77-14 stamped PAL chips with the same code as what we have found in D77-15 PAL chips and vice versa. Assuming the PAL chips themselves are the original ones from Taito (and I have no reason to see why they wouldn’t be) then my theory is, as they are all PALCE16V8 chips, which are reprogrammable, they have simply been reprogrammed by the bootlegger/converter to use whatever version they needed. This would keep it looking that little bit more authentic and also cuts down on the cost of buying a GAL16V8.
If you check in the MAME source too, every game that has program ROM’s of size 0x40000 uses the D77-14 PAL and every game that has program ROM’s of size 0x80000 uses a D77-15 PAL.
Hopefully that will clear up a bit of the confusion surrounding this.
GuidesComments Off on Namco System 1 custom ’64A1′ replacement
Mar072015
First of all I want to thank JROK for providing me all the technical info and allowing its public release, without his help I would not have ever made.Let’s start with the story.
Some time ago a friend of mine sent me his Splatterhouse PCB bought as working saying it got stuck upon boot on ‘ROM TEST START!! PLEASE WAIT..’ message displayed upside down on a screen filled with red zero.So I started to investigate on the net and found that usually this kind of issues are caused by a faulty custom chip marked ’64A1′ @M4 on ROM board.This was confirmed by swapping this IC in another CPU board of Galaga88 with this missing component , in this case I got an ‘EEPROM ERROR’ message which is a further proof of the fault.
Thanks always to JROK we know that this ’64A1′ custom IC is nothing else than a HD63701 MCU with the exception of two custom opcodes not present in original part.You can go deeper into technical reading here:
So, programming a blank HD63701 MCU with the available dump from MAME won’t work due the presence of these two custom opcodes.So, patching a ROM is needed.
In the specific you have to change three bytes in the ROM “VOICE0” at a specific offset.For example : in Splatterhouse the offset is $FA8B and the new HEX values are “20 01 56”.
The string to search for in HEX is “B7 C0 00 6E 00” and the first 3 bytes must be changed to “20 01 56”
The patch seems to be needed at offset $FA8B for most games, but not all. Here’s a reference table :
PacMania -$FA8B
Tank Force – $FA29
Blazer – $FA8B
Dragon Spirit – $FA8B
Galaga 88 – $FA8B
Marchen Maze – $FA8B
Splatterhouse -$FA8B
Rompers – $FA8B
Blast Off – $FA8B
World Court – $FA8B
World Stadium (and WS ’89, WS ’90) – $FA8B
Bakutotsu Kijuutei (Baraduke 2) – $FA8B
Beraboh Man – $FA4E
Dangerous Seed – $FA8B
Face Off – $FA29
Pisto Daimyo no Bouken – $FA8B
Puzzle Club – no voice ROM !
Quester – $FA1B
Souko Ban Deluxe / Boxy Boy – $FA8B
Yokai Douchuuki (Shadowland) – $FA8B
So, it was only matter to find some real blank HD63701.My first attempt failed since I bought as new some ICs that they turned out to be already programmed and, since they were the plastic HD637B01VOP one-time-progfammable version, they were unusable for my purpose.But then I was luck and found some HD63701VOC UV erasable ones:
So, it was only matter to program one of these MCU with MAME dump using my Hi-Lo Systems ALL-11C EPROM programmer and, at the same time, replace the ROM ‘VOICE0’ with the properly patched one.Once done, I had confirmation of what the good JROK said about. Operation ‘NAMCO custom 64A1 replacement’ accomplished.
