JAMMArcade.net – Page 81

Crime City and Fun World – MegaCard MC3 PAL dumps added

PAL Updates Comments Off

Jan 282017

Today we have new entries in our archive.

Coolmod sent dumps from a Crime City (Taito) PCB.Devices were all unsecured (three PAL16L8 and one PALCE16V8), I took care of converting dumps to GAL16V8 fuse maps and I successfully tested them on my board.

Team Europe sent 256KB binary dump (obtained with the Charles MacDonald 27C020 PLD adapter) of the PAL16L8 from a Fun World – MegaCard MC3 PCB.I reversed equations into a GAL16V8 fuse map which is untested for now since board is not working.Thanks to both for their contribution.

Lastly, I successfully adapted into a GAL16V8 the bipolar PROM @7A – IC52 from a Vigilante (Irem M75 hardware) PCB , you can find .JED in the archive section.

Demon’s World/Horror Story repair log

PCB Repair Logs Comments Off

Jan 282017

Got this Demon’s World PCB (also known as Horror Story in Japan but game is multi-regional since it can be configured for different regions via the DIP switches) for a repair :

Board was not working, upon boot it showed the typical black/white stripes (common to all Toaplan boards) sign that main 68000 CPU has properly been initialized but then sat on a black static screen :

As said the CPU was properly running on power up but then halted before entering in game, data/address busses were both silent, usally this happens when CPU can’t find addressable devices.So I went to piggyback RAMs on board.When I did it on four 62256 @18F, 19F, 21F, 23F :

I got this error:

I removed the four chips, most of times they resulted good when tested out-of-circuit but sometimes they randomly failed due probably weak cells.Infact when I installed new RAMs I was greeted by this screen:

Board perfectly working, no further issue found.Another repair log archived.

Commodore 64 ‘breadbin’ repair log #7 – bad characters part #2

Jan 262017

This is part two of my C64 repair which documents the replacement of the bad character generator rom using a standard 27c64 EPROM. My local electronics hobby store did not have anything else on hand; I was hoping for a 27c32 because that’s what most folks on the internet seem to be using to get this repair done. I didn’t want to wait, so I settled on the 27c64.

The first step was downloading a c64 character rom ( 901225-01 ) with a checksum of $F7F8 from the internet. There are plenty of sources for these.

After downloading the 4kb binary I ran the following command under Windows to fill up the entire 8kb of address space of the 27c64 ( upper and lower 4kb have the same data ). I couldn’t quite remember which half I needed to burn the contents to so this was a quick and fail safe solution.

copy /b 901225-01.bin+901225-01.bin 901225-01-doubled.bin

I take the 8kb binary ( 901225-01-doubled.bin ) and burn the image to my 27c64 EPROM.

I bend the following pins outward on the 27c64 and cover the window with a sticker once the data is written.

1,2,20,23,27 & 28 ( bent out ).

I made an adapter using a machined pin socket. This is the diagram I used to re-wire the chip which I found on this German site.

https://forum.classic-computing.de/index.php?page=Thread&threadID=4694

2532 pin 18 -> 27c64 pin 23 ( A11 )

2532 pin 21 -> is not connected ( VPP )

27c64 pin 20 -> 27c64 pin 22 ( /CE & /OE tied )

27c64 pin 1,2,26,27 & 28 ( VPP,A12,NC,/PGM & VCC all tied ).

Once I finished wiring it was time to double check my work. I then select a 2532 device on Max Loader, load the original downloaded character generator rom into the buffer; this has a checksum of F7F8 which will be used for verification purposes.

With the wiring complete I’m now ready to verify it’s contents. I will read the device as a 2532 EPROM and if all goes well it should report a checksum of F7F8

With the re-worked EPROM inserted into the ChipMax I hit verify. F7F8 was what I was after.

With that result I was so confident it was going to work that I trimmed the protruding pins and inserted the device into the C64 to produce the results I expected.

Outrun Music Extender

Projects Comments Off

Jan 222017

Cmonkey and me worked on this project back in March 2015.
Cmonkey found that the new tunes added to the 3DS release of Outrun were in the same format as the original arcade. With that in mind he set about adding the tunes to his Outrun arcade PCB. He succeeded but the problem was there wasn’t enough room in the standard EPROM’s to add these alongside the existing music.
My contribution started here and found one of the pins of the PLD used to select chips was essentially unused so I could use this to switch the new music in and out. Cmonkey modified the code so that the gear shift lever switched in the new tunes.
I designed a PCB which will slot directly into the Z80 code EPROM socket on the Out Run board set. The PCB incorporates a PLCC32 socket and map the pins of a 28-pin 27512 EPROM to the equivalent pins of a PLCC32 memory (39SF010A or equivalent).

Original mock up of the PCB

Parts required for this are
1 x PLCC32 socket
1 x 1Mbit PLCC32 flash memory (39SF010A or equivalent)
4 x 27512 EPROM’s for the patched 68000 code
1 x GAL16V8 for new Z80 address decoding
2 x 14-way pin headers
1 flying wire to link the A16 point on the PCB to pin 18 of the GAL

Note: Pin 18 of the GAL needs to be removed from the socket in order to work

Vapor Trail PLDs redumped, Cameltry and Invasion (Midway) PAL dumps added

PAL Updates Comments Off

Jan 192017

Today we have some new PAL dumps.

Coolmod sent in dumps from a Taito Cameltry PCB, they were obtained from three unsecured PAL16L8, I took care of converting them to GAL16V8 fuse map and he successfully tested them back on board.He sent also a dump of an unsecured GAL22V10 found on the gun I/O board of an Invasion – The Abductors PCB ( light gun rail shooter released by Midway in 1999), board was faulty so we assumed this dump as working.Thanks to him for the contribution.

I redumped the PLDs from a Vapor Trail PCB after testing the dumps we had and realized they didn’t work except one.Devices on my board were five secured GAL16V8 labeled by hand from ‘0’ to ‘4’.

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