ROM3 replaced by my custom ROM, at times succeeds in programming the VDP but locks when accessing RAM.
Maybe something messes with the bus, or some bad solder... an almost impossible problem to track down

Tom, thanks for all the material you sent. Currently I can't make sensible tests until I reconnect the two boards, but I'd like to make it in a clever way. Two options I can think of: install a 2x17 female header so that I can plug-unplug without desoldering, or install two 2x17 90° male headers and...

Some more pics...

Hi Scouter3d, thank you for your reply. I'll provide more detailed information and pics in the next days, however the fault is that I get a dark green screen with the usual annoying sound at startup. This leads me to think that the cpu doesn't even attempt to program the VDP or reset the PSG. Insert...

Inside:

Hi everyone, my friend Luca (MaDrigal) pointed me to this thread (and especially to user Mobsie and Scouter3d) for help. Recently, I've been lucky enough to acquire a Laser 2001 in its box, although incomplete. It is a german version. The unit was given to me as non-working but I felt confident I co...

Hi everyone, as probably many others here I'm just another kid of the '80s hooked into the 8bit world and I admit the CV has always had a special fascination, so I came here looking for extra info :) I've also been thinking about learning to program it, who knows, it may always come in handy someday...