Connect keyboard. Hold/wedge the resest button in. power up. Check that A2 is toggling fast (4Mhz or so). A3 will be toggling at half the speed and so on all the way up to A21 which will be just a few kHz. Probe these at both MEMC and at the ROMs (the other side of the address latches). If you find any that aren't toggling, or toggling at not half the rate of their neighbour, fix that first or there's no point going further.Has anyone maybe got any pointers on what to look at first? I do have an oscilloscope to work with.
I was trying to find the board schematics also, but not able to find any?
The schematics are here : https://chrisacorns.computinghistory.or ... A5000.html (scroll to "technical drawings")
Statistics: Posted by IanJeffray — Thu Jan 25, 2024 10:58 pm