Mar 062016
 

I bought a Vectrex system made in 1982 on an Facebook retro group a couple of weeks ago fairly cheap, that had a strange fault where the game would loop on the internal minestorm game. Here is a video of the fault.

My guess was that it was an issue with the rams (which are 2114 rams) or an issue with the rom.

Yesterday I took it apart, which is not an easy task, and removed the rams and fitted sockets. Both rams tested ok. I then removed the rom which was a D2763-4. I managed to read it as a 2764 eprom on my programmer, and checked it against the bios “exec rom intl 284001-1” from Mame, which showed it had one “bit” of bad data! I went a step further and used the rom data on Mame to see what it did. Unsurprisly it crashed at the same point as the Vectrex, which confirmed the rom was at fault. I re-burnt a new bios file to a 2764 eprom, put the Vectrex back together, and I now have a working system 🙂