29 Oct
2011
29 Oct
'11
11:56 p.m.
Chuck Guzis wrote:
How about the IMP-16 CROMs? Again, I think it takes a
separate rig
to read those.
You can't easily get all of the microprogram out of those electrically,
because part of the microword is interpreted internally by the
microsequencer. It's probably easiest to read them by decap and
microscope. I've got spares of the basic and extended instruction set
CROMs, so I might do this. I only have one of the "POWR I/O" CROM, so I
don't want to sacrifice it. I haven't ever found the CROMs for the
IMP-4 and IMP-8, unfortunately.
Similarly, the decode PLAs of the CP1611 control chips for the PDP-11
and AM100 (WD16) and the CP2151 control chip of the WD90/900/9000 Pascal
Microengine need to be extracted. Reading the MICROMs (CP1631, CP2171)
is relatively easy.