I'm trying to help someone out with their Laser Wars CPU.
It boots right in to the settings menu and "automatically runs through them" at high speed - in advance mode as far as I can tell - and just keeps running through them over and over again WEIRD!!! It's like you have your finger on the "advance" switch and never let go...
1) Changed processor - no difference
2) Changed ram - no difference
3) Checked inputs/outputs at 7402 at 1F (Nor gates from the test switches on the door). Inputs are all high and outputs low as expected. Pin 8&9 High and Pin10 Low.... Pin 5&6 High and Pin4 Low (all correct)
4) Game Rom - I have burned 2x new ROM's 27256 using the code from IPDB but neither will boot the board? Just hangs and crashes on boot. This confuses me! as the original ROM boots in to this issue so I really wanted to change the Game Rom. I'm using M27C256B. They burn and verify but just won't boot the board?? I loaded the IPDB code in to the buffer and "verified" the original game rom and it verified ok. So the IPDB code looks right... baffled
HELP?
Also - I do not have a "laser war" so for testing I am just connecting power and displays on the CPU on one of my DE Machines to see the fault