> > > There is a note in the M9301 Operator’s Manual about the layout of the > PROMs - words split into 4 bit fields programmed in all the PROMs in > “parallel”, lower 8 bits inverted to support extra invert in the switch > circuitry, and higher-addressed bank in the lower-half of the PROMs. 512x4 > tri-state parts. Anybody have any particular part recommends for the > PROMs? I haven’t been able to find engineering drawings for the M9301 > online so far to check the original PROM part numbers, either. > >
The M9301 Engineering Drawings can be found in the PDP-11/04 print set. http://bitsavers.trailing-edge.com/pdf/dec/pdp11/1104/MP00019_1104_EngrDrws_Feb78.pdf The PROMs are standard 512x4 TS PROMs. Signetics 82S131 / Harris 7621 / MMI 6306 / F 93446 > I may also have a go at writing a program I can toggle in to read the > contents of my failing M9301 and dump them out over the console serial to > enable a systematic comparison with Noel’s listing. > > cheers! > —FritzM. > >
