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Re: [midatlanticretro] Re: makeshift IBM monitor

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  • Evan Koblentz
    ... Sorry to bog down the list in details. I meant to reply to Brian off-list.
    Message 1 of 23 , Jun 1, 2009
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      Evan, I'm available most evenings after 8pm. I think you have my cell phone #, if not, email my home e-mail and I'll send you that and my address..   
          
      Brian, can we meet at the mall (or some other central location) like we 
      did when you retrieved Chris' bag?
        
      Sorry to bog down the list in details.  I meant to reply to Brian off-list.
    • 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 2 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 3 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 4 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 5 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 6 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 7 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 8 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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