Modifying microcode

On 06/02/2018 02:45 PM, Warner Losh via cctalk wrote: On Sat, Jun 2, 2018 at 12:43 PM, Tony Duell via cctalk < cctalk at classiccmp.org<mailto:cctalk at classiccmp.org>> wrote: On Sat, Jun 2, 2018 at 7:37 PM, Alan Frisbie <Flash688 at flying-disk.com><mailto:Flash688 at flying-disk.com> wrote: Tony Duell <ard.p850ug1 at gmail.com><mailto:ard.p850ug1 at gmail.com> wrote: until the 8085 CFE loaded the microcode. Loaded from a TU58 cartridge, which is the main reason my 11/730 is not running at the moment. The hardware is fine, I've rebuilt the drive rollers, but as yet don't have a readable tape (not even blank, to write the microcode onto). I'm pretty sure that I have a complete set of 11/730 TU58 tapes in my storage unit. I might even have some brand new tapes. If I can find them, I would be happy to send them to you. They have been sitting in storage for probably 20 years, so there are no guarantee that they are readable. Thanks... I will certanly give them a go. I am pretty sure the problem I am having is the tape, I get a low (and varying) amplitude signal at the output of the read amplifier, it varies with different tapes, and it's much the same both on the drive in the 11/730 and a standalone TU58 I have. Given the vagaries of tape, I'm surprised nobody has made a simple TU58 emulator that can feed the proper microcode bits to the 11/730... Then again, maybe there's no market for that. There are TU58 emulators: https://www.torok.info/computing/pdp11/tu58/ https://www.ak6dn.com/PDP-11/TU58/tu58em/ retrocmp.com/tools/tu58fs bill