cwilbar
Well-known member
I have been working on a Marble Madness LSI cartridge.
It came with the EPROMS, security chip, and SLAG chips missing.
I installed 4 NOS SLAGs, burned and installed all of the EPROMS, and installed a Road Blaster's security chip (verified working in a Marble Madness TTL version board).
It is watchdoggging, and once in a while I can get it to flash an error on the screen about ROM at address 200.
I suspected the LS244s so I removed those, installed sockets and replaced those.
Same behavior.
Not sure where to look next.
It came with the EPROMS, security chip, and SLAG chips missing.
I installed 4 NOS SLAGs, burned and installed all of the EPROMS, and installed a Road Blaster's security chip (verified working in a Marble Madness TTL version board).
It is watchdoggging, and once in a while I can get it to flash an error on the screen about ROM at address 200.
I suspected the LS244s so I removed those, installed sockets and replaced those.
Same behavior.
Not sure where to look next.

