Question to the hardware hackers on this list (or maybe a retired HP
engineer): is there some particular feature in the two Clocks, SYNC
and POR which causes Classic HP Mostek ROMs to fail with a read timing that works with the like AMI parts having the same HP part number ? I have examined signals of CTCs from both Mostek and AMI on the scope and saw no feature that should make such a big diffence between go / nogo. The trouble is, the Mostek ROMs do not start up (they always give out the same dataword on IS) despite the addresses do count up. Seems some state machine within the ROM hangs, so there must be something wrong with the timing sequence, but what detail eluded me I don't know.
Any hint is much appreciated. You may use my above email address but remove everything after the first four lower case digits and the at.
Regards,
Bernhard