furrtek

Konami sprite chips setback

Added 2021-10-07 04:31:06 +0000 UTC

A few days ago I wanted to resume work on the Konami chips, by starting to trace one of the two remaining sprite chips (051937 and 051960).

Pulling the dies from my small collection, I noticed that they were awfully blue, unlike the tilemap chips which appeared silvery with a very slight yellow tint (like most other dies).
Under the microscope, the tint difference wasn't very noticeable but something much more problematic was: most of the metal had disappeared. It had left some faint trenches in some spots, but without enough contrast to guess where the traces were and how they crossed.

I'm not sure how that happened. The four video chips were all from Fujitsu, from around the same period, and were all sent to me by @rndmnkiii a long time ago. I can't remember if I decapped them all in the same run and if I left them cooking for the same duration. I'm only sure that the acid type and temperature was the same.

Did I decap them in pairs and left these two boiling for too long ? Were they made with a different process, or did they came from a different plant ? They're quite larger than the tilemap chips and they have embedded RAM blocks, but that doesn't prove anything.

The consequence of this is that I simply don't have anything to work with.
I've got eBay notifications set up for broken PCBs using these 2 chips, now we've just got to wait (even more)...

Some non-Konami good news to compensate for this however: I'm almost done with the infamously fragile 315-5218 "Sega PCM" :)