Today our member Corrado sent in the PAL dumps from a Sengoku Ace PCB.They are all tested into GAL16V8 targeting device.Thanks to him for this contribution.
Today some addition to our PAL database.With courtesy of user ‘tinhead’ on the EEVBlog forums we can host his recreations of registered PLDs found inside the Hi-Lo Systems ALL-07A EPROM programmer (which I personally use).You can read more about here:
https://matthieu.benoit.free.fr/hilosystem_all-07_universal_programmer.htm
Speaking about arcade PLDs, I successfully reversed into a GAL18V10 targeting device the dump made by Porchy from the PLS153 marked ‘315-5298’ found on some Sega System16B ROM boards (171-570 and 171-5521).
I had this rare Irem Ken-Go PCB (an undumped version included in latest MAME release) from my friend Joachim for a repair:
The board played fine except for an issue where all sprites were formed but missing all colors appearing like black shape:
Sprites generation circuit is located on top board where some customs lie:
Documentation for this specific game was not available but luckily I could know function of the various customs by looking at the R-Type schematics and so identity the one involved in the sprites palette generation:
The custom itself was marked ‘KNA91H014’ in 60 pins QFP package:
Probing it revelead that inputs were fine but outputs had irregular signals:
So I opted for replacing this custom (taking a good one from a dead Vigilante board) :
This was the right move since sprites were correcly restored:
End of job.
Got this Konami Haunted Castle PCB for a repair:
When I powered it up for first time, two were the faults I noticed : sound and sprites were missing.So I started to troubleshoot first issue.The sound circuitry of this hardware is made of an Z80 CPU,a 6116 SRAM, a 27256 ROM and YM3812 DAC plus a couple of custom for PCM samples and music generation (K007232 and ‘K051649’).When I went to probe the Z80, I found that most of data lines were stuck LOW or HIGH.The ROM containing sound code was good as well as the relative RAM.With the help of schematics I figured out that sound code data were latched by a 74LS374 @G11 :
Probing its outpus revealed they were stuck and piggybacking it caused playing some random samples.So I decided to remove the IC :
It failed when tested in my programmer:
Sound was fine but, as I said, sprites were missing (except for some):
Since I already repaired in the past a couple of Haunted Castle boards with identical issue, I knew where to look at.Hardware uses for sprites and tiles some 4464 DRAMs in ZIP package.In particular the two related to sprites are the ones @H3 and @H4:
So I ordered some spare parts from China.When they finally arrived , I could successfully finish my job by replacing them:
Another great game preserved!
Just a quick (but quite important) fix.Got from my friend Josef this spare Capcom C-BOARD with CPS-B-01 ASIC on it:
Whatever game I tried with it, I got sprites issues.Strider for example:
I was pretty sure the CPS-B-01 ASIC was bad, it’s very prone to failure IC but I decided to have a look at it.Doing a continuity test with my multimeter on solderside of the C-BOARD I found two broken traces:
I promptly patched them with some AWG30 wire:
This restored correct sprites:
