On 5/2/20 5:10 PM, Kevin Lee via cctalk wrote: On Sun, May 3, 2020 at 4:23 AM Al Kossow via cctalk <cctalk at classiccmp.org> wrote: [links] I've verified that the microcode dumps of the Soviet 581 LSI-11 clone* are identical to the DEC microcode. That's not particularly surprising, but it does give me confidence that the control chip PLAs should be identical as well. Since they have decoded the control chip PLAs, I should be able to use that to update my LSI-11 microcode disassembly. John took photos of the LSI-11 control chip for me, but I had somewhat more difficulty reading the PLA bits than I did with the WD9000 (Pascal Microengine) control chip, so I didn't complete transcribing the LSI-11 PLAs. I haven't really looked at the WD16 microcode or PLAs yet. * The multi-chip clone. The 1801BM* single-chip PDP-11 microprocessors are not directly based on any DEC design.