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Want to give up my Altair 8800b

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  • Michael George Hart
    About 5 years ago I obtained an Altair 8800b and to the best of my understanding the only thing wrong with it was it had a blown power supply... I have been
    Message 1 of 15 , Jun 9, 2013
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      About 5 years ago I obtained an Altair 8800b and to the best of my understanding the only thing wrong with it was it had a blown power supply... I have been meaning to work on restoring it, but simply have not been able to put aside the time to accomplish the task. Anyone with the first $1500 gets it... Note I believed I payed almost $2,000 on eBay back then.... If anyone is interested I will post detail pictures.

      Thanks

      I, the unwilling, was lead by the unqualified, to do the unbelievable for so long with so little, that I attempted the impossible with nothing

      Sent from my iPad

      On Jun 9, 2013, at 4:43 PM, "toml_12953" <tlake@...> wrote:

       

      I have Extended BASIC 4.0 and 4.1 (Extended BASIC is about 15K long) Neither will run properly on a Z-80. They start OK but all numeric assignment statements fail.

      10 A=4: LET B=9
      20 PRINT A,B
      RUN
      0 0

      --- In altaircomputerclub@yahoogroups.com, "frank99473" <f.schieschke@...> wrote:
      >
      >
      > Hello Tom,
      > which Altair Basic do you want to run?
      > The extended 8K Basic works with my Z80 CPU.
      >
      > Frank
      >

    • deramp5113
      I ve figured out patches to get Extended BASIC 4.0 working on a Z80. All patches are related to parity flag differences between the 8080 and the Z80. There
      Message 2 of 15 , Jun 10, 2013
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        I've figured out patches to get Extended BASIC 4.0 working on a Z80. All patches are related to parity flag differences between the 8080 and the Z80. There ended up being two problems that needed fixing in your example below. One was the actual assignment to the variable, the second was the inverse operation, taking a variable's value and figuring out how to display it.

        Note that as you continue to use Extended BASIC on the Z80 you may uncover more areas where the parity bit causes problems.

        How do you want to apply the patches? Do you want to patch memory yourself with the front panel switches and then somehow save it, or would you like a paper tape file of Ext BASIC 4.0 with the patches already in place?

        Mike

        --- In altaircomputerclub@yahoogroups.com, "toml_12953" <tlake@...> wrote:
        >
        > I have Extended BASIC 4.0 and 4.1 (Extended BASIC is about 15K long) Neither will run properly on a Z-80. They start OK but all numeric assignment statements fail.
        >
        > 10 A=4: LET B=9
        > 20 PRINT A,B
        > RUN
        > 0 0
        >
        >
        > --- In altaircomputerclub@yahoogroups.com, "frank99473" <f.schieschke@> wrote:
        > >
        > >
        > > Hello Tom,
        > > which Altair Basic do you want to run?
        > > The extended 8K Basic works with my Z80 CPU.
        > >
        > > Frank
        > >
        >
      • toml_12953
        ... If you could post both the patch method and a .tap file to the Files area that would be ideal! Thank you so much! Tom L Give a man a fish and you feed him
        Message 3 of 15 , Jun 12, 2013
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          --- In altaircomputerclub@yahoogroups.com, "deramp5113" <deramp5113@...> wrote:
          >
          > I've figured out patches to get Extended BASIC 4.0 working on a Z80. All patches are related to parity flag differences between the 8080 and the Z80. There ended up being two problems that needed fixing in your example below. One was the actual assignment to the variable, the second was the inverse operation, taking a variable's value and figuring out how to display it.
          >
          > Note that as you continue to use Extended BASIC on the Z80 you may uncover more areas where the parity bit causes problems.
          >
          > How do you want to apply the patches? Do you want to patch memory yourself with the front panel switches and then somehow save it, or would you like a paper tape file of Ext BASIC 4.0 with the patches already in place?
          >
          > Mike

          If you could post both the patch method and a .tap file to the Files area that would be ideal! Thank you so much!

          Tom L

          Give a man a fish and you feed him for a day. Teach him how to fish and you won't see him again for weeks.
        • deramp5113
          In the meantime, I ve been doing more digging into the BASIC disassembly for other problems related to the parity bit. In addition to the assignment and print
          Message 4 of 15 , Jun 12, 2013
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            In the meantime, I've been doing more digging into the BASIC disassembly for other problems related to the parity bit.

            In addition to the assignment and print problem you demonstrated, there are, as expected, numerous other areas where the parity bit is set wrong by the Z80 and then tested assuming 8080 party bit rules. I'm going to methodically address every one of these I find in the disassembly as opposed to just fixing demonstrated problems. This may take a bit longer!

            Because of the size of the resulting patches, I'm also going to have to trick BASIC into saving some room for the patches that it doesn't reclaim after initialization.

            Nothing is ever simple, but why stop now?

            Mike


            --- In altaircomputerclub@yahoogroups.com, "toml_12953" <tlake@...> wrote:
            >
            >
            >
            > --- In altaircomputerclub@yahoogroups.com, "deramp5113" <deramp5113@> wrote:
            > >
            > > I've figured out patches to get Extended BASIC 4.0 working on a Z80. All patches are related to parity flag differences between the 8080 and the Z80. There ended up being two problems that needed fixing in your example below. One was the actual assignment to the variable, the second was the inverse operation, taking a variable's value and figuring out how to display it.
            > >
            > > Note that as you continue to use Extended BASIC on the Z80 you may uncover more areas where the parity bit causes problems.
            > >
            > > How do you want to apply the patches? Do you want to patch memory yourself with the front panel switches and then somehow save it, or would you like a paper tape file of Ext BASIC 4.0 with the patches already in place?
            > >
            > > Mike
            >
            > If you could post both the patch method and a .tap file to the Files area that would be ideal! Thank you so much!
            >
            > Tom L
            >
            > Give a man a fish and you feed him for a day. Teach him how to fish and you won't see him again for weeks.
            >
          • Erik Klein
            Can you post additional info and images, please? Thank you, Erik From: altaircomputerclub@yahoogroups.com [mailto:altaircomputerclub@yahoogroups.com] On Behalf
            Message 5 of 15 , Jun 15, 2013
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              Can you post additional info and images, please?

               

              Thank you,

               

              Erik

               

              From: altaircomputerclub@yahoogroups.com [mailto:altaircomputerclub@yahoogroups.com] On Behalf Of Michael George Hart
              Sent: Sunday, June 09, 2013 1:58 PM
              To: altaircomputerclub@yahoogroups.com
              Subject: [Altair Computer Club] Want to give up my Altair 8800b

               

               

              About 5 years ago I obtained an Altair 8800b and to the best of my understanding the only thing wrong with it was it had a blown power supply... I have been meaning to work on restoring it, but simply have not been able to put aside the time to accomplish the task. Anyone with the first $1500 gets it... Note I believed I payed almost $2,000 on eBay back then.... If anyone is interested I will post detail pictures.

               

              Thanks

              I, the unwilling, was lead by the unqualified, to do the unbelievable for so long with so little, that I attempted the impossible with nothing

               

              Sent from my iPad


              On Jun 9, 2013, at 4:43 PM, "toml_12953" <tlake@...> wrote:

               

              I have Extended BASIC 4.0 and 4.1 (Extended BASIC is about 15K long) Neither will run properly on a Z-80. They start OK but all numeric assignment statements fail.

              10 A=4: LET B=9
              20 PRINT A,B
              RUN
              0 0

              --- In altaircomputerclub@yahoogroups.com, "frank99473" <f.schieschke@...> wrote:
              >
              >
              > Hello Tom,
              > which Altair Basic do you want to run?
              > The extended 8K Basic works with my Z80 CPU.
              >
              > Frank
              >


              No virus found in this message.
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            • deramp5113
              I created a patched version of Altair Extended BASIC 4.0 that will run on a Z80 and placed it in the files section (Files Altair 8800 Paper Tape Images
              Message 6 of 15 , Jun 16, 2013
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                I created a patched version of Altair Extended BASIC 4.0 that will run on a Z80 and placed it in the files section (Files > Altair 8800 Paper Tape Images > Extended Basic 4.0 for Z80).

                The patched version is available as a .bin file and as a paper tape image. I used Martin Eberhard's "makealt" utility in the "Working with Paper Tapes" folder to create the paper tape image from the .bin file. The source file "patches.asm" contains and describes the patches that had to be made.

                Mike

                --- In altaircomputerclub@yahoogroups.com, "toml_12953" <tlake@...> wrote:
                >
                >
                > The TDL ZPU manual mentions an Appendix C which contains a patch for
                > Altair BASIC so it can run on a Z-80. Unfortunately, every pdf of the
                > ZPU manual I can find is missing Appendix C! Does anyone here have a
                > copy of Appendix C they can post or give me exact instructions on how to
                > patch Altair BASIC to run on a Z-80?
                >
                > TIA
                >
                > Tom Lake
                >
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