Friday 18 August 2023

Renegade repair log

 Bought some time ago from US an original Renegade PCB :

I was after this board since years because I like the game, a beat'em up developed by Technōs Japan and published in 1986 by Taito.You can read more about this game here :

Renegade : an immediate predecessor to Double Dragon

The board was marked as faulty with a sprite issue like stated on the sheet that was inside the package :

But, actually, when I first powered board up I was greeted by a static garbage screen :

I reseated the ribbon cables and gave a clean to the pins of the connectors, the board finally booted up and I could see sprite issue that affected some of the enemies :

The sprites data are stored in twelve 27256 EPROMs located on bottom video board :

I dumped them and noticed that my programmer gave a different checksum on each reading of the device labeled 'ND-5' @IC79 :

This is the clear symptom that the EPROM is faulty.Indeed, any of the dumps of this device was not recognized by MAME :

 

Out of curiosity, I tried one of the bad dumps in MAME and got exactly the same issue of the PCB :

I programmed a good 27256 EPROM with MAME ROM file, this fixed the sprite issue :

 

No other issue found therefore board 100% working and another classic added to my collection.


Thursday 3 August 2023

Seta 'X1-007' reproduction

Recently 'Furrtek' decapped the Seta 'X1-007' custom chip donated by me (this part, in SDIP42 package, is used on many Taito/Seta PCBs as RGB latch and video SYNC generator)

I took the chance to put his (always) brilliant work into practice and made a replacement of this custom IC using a +5V CPLD to embed all the logics that 'furrtek' extracted from the silicon die :


Testing of the reproduction on Insector X PCB was successful :

A huge thanks again to 'Furrtek' for his invaluable work.