spett wrote:My 8MHz signal is good but cpu halts after ~22 sec.
IIRC Glue does assert /BERR 64 clocks (8MHz) if it does not see /DTACK asserted.
Do the following:
if /BERR is asserted then check the history before this assertion.
There should be /AS asserted and /DTACK not being asserted.
Now if you found this position then CPU wants to access some device (DRAM = MMU, peripheral (= DMA, MFP, PSG...). So there should be some /CS asserted. Check which /CS is asserted. Then you should have found the "victim" which does not respond correctly to a /CS. Either /CS line is broken, some address/data lines are broken... can have many reasons.
spett wrote:Are all chip revisions interchangable?
In general: yes. But stay away from Atari ASICs of the manufacturer IMP.
spett wrote:What brand/type is the original 28pin 1MBit TOS chips? Thinking of reading mine but can't figure out chip type. I do have a rather good eeprom burner but chip detect fails..
That's an "Atari rarity". These are PROMs that do not need typical EPROM lines like Vpp. So they omitted these - et voilá: it fitted into a 28pin package. 1MBit (27C1001/27C010) EPROMs do have 32pins. So you either need an adapter PCB, or do some pin bending and wire-wrapping or (most comfortable option) program six 27C256. Then you will need to set three solder-bridges near the ROM sockets. Check schematics.
Hope that helps.