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RE: [midatlanticretro] M9312 Diagnostic PROM for PDP-11/24 (23-774F1)

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  • Christian R. Fandt
    ... Hi Bill, Could be a newer PROM than the EK-M9312-TM-003 will list, which is likely the latest revision given there s no -004 as far as I can see. The
    Message 1 of 4 , Jul 14, 2013
      At 11:34 AM 7/14/2013, B Degnan wrote:

      There was a diagnostic ROM on that 9312 boot module in my machine numbered
      23-774F1 of which I asked the C'Cmp list about. Back then I could not find
      anything at all on that part, i.e., what diags it did, other functions,etc.


      The fellow who'd contacted me has an 11/24 with that PROM and is looking for
      the same info I once had been.

      So, I'm asking here if there is anyone who may have knowledge of this device
      in any way (actual part, source listing, etc.)?



      Short answer - It's probably a newer ROM that is not in many M9312 docs, you
      need to find the addendum to the orig doc, or a relatively rare article/doc
      that talks about using an older ROM card in a newer 11/24 system. This
      would not have been a typical coupling in the early-mid 80's

      Hi Bill,

      Could be a newer PROM than the EK-M9312-TM-003 will list, which is likely the latest revision given there's no -004 as far as I can see. The 23-774F1 PROM is most likely contemporary to the 11/24 system during its production in the early 80s.

      As you probably already know the last two chars of a M9312 ROM indicates its
      function. F1 = console emulator and diagnostic routine. The last two chars
      for a boot ROM is A9.

      Based on this and older ROM docs I think you have just the main 11/24
      console emulator and diagnostic ROM, a later version with ascii console
      emulator routines and diagnostics for the 11/24.

      If you check Appendix E section E.2 of EK-M9312-TM-003 (manual # for the
      M9314), appendix E has a cross reference table that you can use to determine
      from the part number and some memory testing which device this ROM was made
      for. Problem is that your ROM is for a device that is newer than the
      original M9314 doc was created, like a hard drive or DEC Professional Series
      diskette drive. It's not going to be easy without the update/addendum
      published for EK-M9312-TM-003, you'll only be able to determine which ROM
      it's *NOT* otherwise.

      I've got just the -001 rev in print. Plus the Field Maintenance Print Set MP00617, both tucked away safely in the library upstairs. Somewhere online I'm sure there's a -003 rev in PDF, just haven't looked yet. (I think you really meant '9312' as there is no such module as a 9314 :-) )

      You may need to put this card with ROM in a working older system like a
      11/40 that has a front panel to determine the ROM contents. I am pretty
      serious about bringing my 11/40 to the August workshop this time, if with
      help I can get it running we can use it to check the ROM, I will bring a
      M9312 just in case.

      As I said I got shed of the 11/24 around a dozen years ago. I'll pass your comments on to the other person who's got an 11/24 with the subject 23-774F1 PROM.

      Maybe one of the other PDP mavens around here has an 11/24 or perhaps a pile of loose PROMs which may include a 23-774F1 (hope, hope, hope! :-)  )

      Have fun.

      Always do when I'm able to play with my 'toys'. If not, then I find something else around here with which to have fun. But in recent years, I've had little time to do that. I do antique car radio and home radio repair and restorations on the side, plus have a full time job in the engineering dept of an unnamed major independent diesel engine manufacturer who has a plant nearby.

      Thanks for your input Bill!


      Christian R. Fandt,    Electronic/Electrical Historian
      Jamestown, NY  USA      cfandt@...
              Member of Antique Wireless Association                        
              URL: http://www.antiquewireless.org/
                      http://www.antiquewirelessmuseum.com  (Upcoming Museum - Grand Opening August 2013!)

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