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Re: [midatlanticretro] Re: makeshift IBM monitor

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  • Joe Giliberti
    Here s as much info as I can pull off the mainboard Machine Serial: 0177038 On the planar: SW1 on on on on off on on off SW2 on off on on off off off off U28
    Message 1 of 23 , Jun 1, 2009
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      Here's as much info as I can pull off the mainboard

      Machine Serial:
      0177038

      On the planar:

      SW1
      on on on on off on on off

      SW2
      on off on on off off off off

      U28
      Empty Socket

      U29
      MK35748 J
      5700019
      ZA
      (copyright) IBM 1981
      D Malaysia
      8135 Q

      U30
      5700027
      (copyright) IBM 1981
      XE
      (motorola symbol) 8201BNM

      U31
      (motorola symbol) 5700035
      (copyright) IBM 1981
      XE8135ANM

      U32
      MK36728 P
      5700043
      ZA
      (copyright) IBM 1981
      D Malaysia
      8142 D

      U33
      MK36C35N-4
      1501476
      ZA
      (copyright) IBM CORP
      1981, 1983
      D Malaysia

      U34
      (not socketed)
      NEC
      PIY229-147
      D8253C-5

      Has a total of 36 of what I believe to be memory chips. Nine are soldered direct to the board, the remaining 27 are socketed
      The chips are marked:

      (AMD symbol) AM9016DPC
      8144WPP

      All 36 are the same chips


    • B Degnan
      U33 MK36C35N-4 1501476 ZA (copyright) IBM CORP 1981, 1983 D Malaysia Tells you it s a 2nd REV16K-64K (upgraded) ROM set. The first rev did not have a routine
      Message 2 of 23 , Jun 1, 2009
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        U33
        MK36C35N-4
        1501476
        ZA
        (copyright) IBM CORP
        1981, 1983
        D Malaysia

        Tells you it's a 2nd REV16K-64K (upgraded) ROM set.  The first rev did not have a routine for using hard drives, and some other things so most people upgraded the ROMS so they could use newer parts and memory.



        Here's as much info as I can pull off the mainboard

        Machine Serial:
        0177038
        this year I worked on the following other 16-64K boards, so yours is right in there among them, definitely an original, probably from late 1981 early 1983.:

        0159618
        0239462
        0192592 (MARCH's with original ROMS)

        On the planar:

        SW1
        on on on on off on on off

        SW2
        on off on on off off off off


        you have a full complement of RAM (64K) on the motherboard. 

        I assume you have SW1 reversed.  Up means "on" if facing from the front looking down. 
        If you have a co-processor, two drives, CGA monitor then SW1 should be: [off on -- -- on off off on] (where pertains to RAM).

        If SW1's 5 is up and 6 down  - that means CGA display.  Monochrome 5 and 6 are down.  Never mix and match without first changing the switches before powering on.  Otherwise you will fry the board and short the system.

        Math co-processor 2 = up/on.

        In a nutshell it looks like you have a standard configuration, no changes needed assuming you use a CGA monitor.  Don't try to use monochrome with these settings.  Someone did that to MARCH's 5150, and we had to replace the display card as a result. 

        Hope this helps.

        Bill

      • Joe Giliberti
        Thanks for the info, Bill Some more questions Does it matter whether I take video from the CGA port or the composite? So I could, if I wished, install an MFM
        Message 3 of 23 , Jun 1, 2009
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          Thanks for the info, Bill
          Some more questions

          Does it matter whether I take video from the CGA port or the composite?
          So I could, if I wished, install an MFM hard drive/controller, or perhaps a hardcard. Correct?
          Also, due to the different ROM, will it support a full 640k, or the 544k from the first gen?

          Joe

          On Mon, Jun 1, 2009 at 10:45 PM, B Degnan <billdeg@...> wrote:


          U33
          MK36C35N-4
          1501476
          ZA
          (copyright) IBM CORP
          1981, 1983
          D Malaysia

          Tells you it's a 2nd REV16K-64K (upgraded) ROM set.  The first rev did not have a routine for using hard drives, and some other things so most people upgraded the ROMS so they could use newer parts and memory.




          Here's as much info as I can pull off the mainboard

          Machine Serial:
          0177038
          this year I worked on the following other 16-64K boards, so yours is right in there among them, definitely an original, probably from late 1981 early 1983.:

          0159618
          0239462
          0192592 (MARCH's with original ROMS)


          On the planar:

          SW1
          on on on on off on on off

          SW2
          on off on on off off off off


          you have a full complement of RAM (64K) on the motherboard. 

          I assume you have SW1 reversed.  Up means "on" if facing from the front looking down. 
          If you have a co-processor, two drives, CGA monitor then SW1 should be: [off on -- -- on off off on] (where pertains to RAM).

          If SW1's 5 is up and 6 down  - that means CGA display.  Monochrome 5 and 6 are down.  Never mix and match without first changing the switches before powering on.  Otherwise you will fry the board and short the system.

          Math co-processor 2 = up/on.

          In a nutshell it looks like you have a standard configuration, no changes needed assuming you use a CGA monitor.  Don't try to use monochrome with these settings.  Someone did that to MARCH's 5150, and we had to replace the display card as a result. 

          Hope this helps.

          Bill


        • B Degnan
          ... only use a real cga monitor in the CGA port. do not use the composite. ... yes but this system did not come with a hard drive and would not be in the
          Message 4 of 23 , Jun 2, 2009
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            Joe Giliberti wrote:
            Thanks for the info, Bill
            Some more questions

            Does it matter whether I take video from the CGA port or the composite?
            only use a real cga monitor in the CGA port.  do not use the composite.

            So I could, if I wished, install an MFM hard drive/controller, or perhaps a hardcard. Correct?
            yes but this system did not come with a hard drive and would not be in the spirit of what it was originally.

            Also, due to the different ROM, will it support a full 640k, or the 544k from the first gen?

            full 640.  Should be at 640K now.
            Joe


            P.S. - Evan - the disk you gave me for the IBM at MARCH has some bare spots, the drive needs to be cleaned or replaced.    Do we have any replacement Tandon 100-2a drives at MARCH?

            Bill
          • Evan Koblentz
            ... I don t know.
            Message 5 of 23 , Jun 2, 2009
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              > Evan - the disk you gave me for the IBM at MARCH has some bare spots,
              > the drive needs to be cleaned or replaced. Do we have any
              > replacement Tandon 100-2a drives at MARCH?
              I don't know.
            • Mr Ian Primus
              ... The drive probably just needs a good cleaning. I ve never seen a Tandon in an IBM fail so badly as to scrape up disks. The heads are probably just really
              Message 6 of 23 , Jun 2, 2009
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                --- On Tue, 6/2/09, Evan Koblentz <evan@...> wrote:

                > > Evan - the disk you gave me for
                > the IBM at MARCH has some bare spots,
                > > the drive needs to be cleaned or replaced. 
                >   Do we have any
                > > replacement Tandon 100-2a drives at MARCH?
                > I don't know.

                The drive probably just needs a good cleaning. I've never seen a Tandon in an IBM fail so badly as to scrape up disks. The heads are probably just really dirty. Also, the disk itself could have been compromised - some brands are more apt to start shedding oxide with age.

                -Ian
              • Bill Degnan
                ... in an IBM fail so badly as to scrape up disks. The heads are probably just really dirty. Also, the disk itself could have been compromised - some brands
                Message 7 of 23 , Jun 2, 2009
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                  -------- Original Message --------
                  > From: "Mr Ian Primus" <ian_primus@...>
                  > Sent: Tuesday, June 02, 2009 8:56 PM
                  > To: midatlanticretro@yahoogroups.com
                  > Subject: Re: [midatlanticretro] Re: makeshift IBM monitor
                  >
                  > --- On Tue, 6/2/09, Evan Koblentz <evan@...> wrote:
                  >
                  > > > Evan - the disk you gave me for
                  > > the IBM at MARCH has some bare spots,
                  > > > the drive needs to be cleaned or replaced.
                  > > Do we have any
                  > > > replacement Tandon 100-2a drives at MARCH?
                  > > I don't know.
                  >
                  > The drive probably just needs a good cleaning. I've never seen a Tandon
                  in an IBM fail so badly as to scrape up disks. The heads are probably just
                  really dirty. Also, the disk itself could have been compromised - some
                  brands are more apt to start shedding oxide with age.
                  >

                  True on all counts. I was just curious about whether we had another drive
                  if next time I come up and I can't fix the problem, I can bring a spare
                  drive if I have one. Hopefully you're right and a good cleaning will
                  suffice, or a new disk. The disk in question is a copy of DOS 2.11 with a
                  few scratched tracks, but not completely bare. I never had issues with
                  these drives when I was working with the system myself, but I was mostly
                  focused on the hardware and did not do much disk exercising other than
                  format a disk in both drives.

                  bd
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