Konami '0005292' reproduction

The  Konami '0005292' is one of the varios custom ICs you can find on Konami 'GX400' arcade system, more precisely on the video board.You can read more about the GX400 hardware here :

Konami GX400

The '0005292'comes in a SDIP64 package :

 

Technically the chip is a counter/clock divider providing all video timing for the system, here's pinout from Nemesis schematics : 

For my reproduction job I used a Salamander bootleg where the functions of the chip have been reversed by using simple 74 logics.After identifying the equivaent circuit I made a replacement based on CPLD :

After some timing clock adjustement the replacement worked fine, here is testing on my Black Panther PCB :

In the next future I will look at the other GX400 custom ICs with the aim of doing a replacement of the whole video board, stay tuned for further updates.

Thundercade repair log

Got for repair an original Thundercade PCB, also known as Twin Formation and 特殊部隊UAG, a vertical shooter developed by SETA and released in 1987.Board was in very good condition :

When I powered it up I got a black screen as the power supply of my test rig had gone into protection so I turned off the power.Using a multimeter I found there was a dead short across GROUND and +12V, the measurement was taken with the probes on the protection zener diode just near the egde connector :

I also noticed there was some burn marks over the sound amplifier heatsink, this was a clear sign of some heavy event (overcurrent or overvoltage on the +12V line)

Anyway, after I removed the zener diode, the short was cleared so I could power the board up again.Game was playable with sound too but sprites were glitched :

Sprites data are stored in eight 2Mbit MASK ROMs :

I dumped all of them (as 27C400 and then I splitted the files in two halves).Doing a MAME ROMs compare all the files were matching the existing set except the one marked 'UA0-10 W51'.To have  confirm I replaced the MAME dump with mine, I launched the emulator and could reproduce exactly the same issue :

 

Since there are no direct replacement of 40 pin 2Mbit MASK ROM I programmed a 27C400 EPROM doubling the MAME ROM file into the progrmmer buffer :

This fixed the issue and board completely.Repair accomplished.