Some time ago Charles MacDonald sent me a dump of a 315-5280 CK2605 PLD from his Sega X board for a project I was working on.
Anyway, after the project finished I forgot about it until now.
The original device was a CK2605 but it is for use in a GAL16V8. It is untested.
Thanks to Charles for taking the time to dump this for me.
Also added the last missing PAL from Dark Seal 2/Wizard Fire.
The PAL is a PAL16L8 and is marked as VA-00 at location K3.
It is presently untested but I will get round to testing all of the PALs we have soon.
Today I manually reversed and tested the last PAL we didn’t have from the Dark Seal PCB.
The PAL in question is a PAL16R4 and is labelled TF-4 located at E12.
Who of us has not played at least once Xevious?
Xevious is a vertical scrolling shooter arcade game that was released by Namco in December 1982.It runs on Namco Galaga hardware. In North America, the game was manufactured and distributed by Atari.
I had on my bench the Namco version:
Board booted correctly, game was fully playable but sprites were missing some lines and also playfiled got some issues:
All GFX customs (the sprite positioner ’12XX’, the object RAM addresser ’04XX’ and the GFX data shifter and mixer ’11XX’) were OK since I swapped them with ones of my Galaga/Gaplus boards.Luckily Namco released schematics for this board so for first I checked the part of circuit involved.All was good until I come across this section:
As you can see there are six 74LS161 counters that take DATA from one 2128 SRAM @2S (addressed by the custom “04XX”):
Three 74LS161 address two of the four 2149 RAMs @5M and 5N:
When I went to probe the two 2149 RAM @5N and 5M I found four address lines (PIN3-6) stuck LOW.As I said before, these are addressed by a counter @5S so I went to use my HP10529A logic comparator on it.All led corrisponding to outputs turned ON while all inputs were correctly working.Desoldered and tested it out-of-circuit confirmed it was bad:
Fitted a good 74LS161 restored correct graphics.
With this repair we conclude the May season of logs.See you hopefully next one!
Got this mint Gundhara PCB, a vertical shooter similar to Ikari Warriors, manifactured by Banpresto in 1995:
When I powered it up game was fully playable but tilemaps were totally wrong :
Before you start every troubleshooting, first thing to do is studying the hardware.MAME is a great help for every repairer with its invaluable source of information provided.In this case here is an overview of the hardware (thanks to driver developer Luca Elia):
This information pointed me in the right direction, the part of circuit to be analysed was this:
You can see on the right part of the above picture the two custom ASIC tilemaps generator marked ‘X1-012’ (QFP100 package).When I checked the one @U45 I found some lifted pins:
A simple reflow of these pins was enough to restore tilemaps:
I was declaring this board 100% fixed but while testing it I noticed something wrong in its sound, some PCM samples were played wrongly (like enemy shots) compared to good reference of MAME.Once again our beloved emulator source gave me an help to pinpoint this trouble.There is another custom ASIC which is a 16 bit PCM chip marked ‘X1-010’ (QFP80 package) in the sound circuitry @U57:
One pin was lifted, a reflow restored correct sound.
Thanks MAME!This repair log is dedicated to you! 🙂