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[Altair Computer Club] Re: CPM on 8800 using original Altair floppy

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  • W Tom
    Now that we can capture Altair diskettes, I d like to run Altair accounting software on an Altair emulator. The Altair accounting software uses BASIC with
    Message 1 of 14 , Feb 2, 2013
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      Now that we can capture Altair diskettes, I'd like to run Altair accounting software on an Altair emulator. The Altair accounting software uses BASIC with Memory set to 59000. The software puts printer drivers above BASIC.

      Do the emulators provide a full 64K RAM after boot like an 8800bt?


      W Tom S
      --- In altaircomputerclub@yahoogroups.com, "deramp5113" wrote:
      >
      > I'll post an image of a drive or two soon. Sounds like altair32 and simh emulators will update soon to fix disk emulation issues. Simh may host a version of the MITS Burcon disk as well.
      >
      >
      > --- In altaircomputerclub@yahoogroups.com, B Degnan wrote:
      > >
      > > Wow that's great. Perhaps you could post the "paper tape" image to the files section? I'd love to try it out.
      > >
      > >
      > >
      >
      > >
      > > -----Original Message-----
      > > From: deramp5113
      > > To: altaircomputerclub
      > > Sent: Wed, Jan 30, 2013 11:14 am
      > > Subject: [Altair Computer Club] Re: CPM on 8800 using original Altair floppy
      > >
      > >
      > > Status update:
      > >
      > > It appears that one of the few, if not the only, version of CPM 2.2 running on
      > > the original Altair floppy drive (88-DCDD) was "Burcon CPM." I have finished
      > > creating a fully documented source of the BIOS for the Burcon CPM by
      > > diassembling a memory dump provided by W Tom.
      > >
      > > With the Burcon BIOS source, I can now generate a Burcon CPM of any memory size
      > > for the Altair disk drive.
      > >
      > > There are a couple of minor bugs in the Burcon BIOS, so a slightly modified
      > > version of the BIOS may also be in order.
      > >
      > > The Burcon BIOS, which runs fine on real hardware, did not run under the
      > > Altair32 or SIMH emulators. After some digging, I found a bug in the floppy
      > > drive emulation code of both of the emulators. After fixing the bug and
      > > recompiling the emulators from source, both emulators now work with the Burcon
      > > disk image.
      > >
      > > The SIMH emulator still has a problem in that SIMH's boot ROM won't boot the
      > > Burcon disk. The loader on the Burcon disk is only two sectors long, but the
      > > SIMH boot ROM code doesn't properly read the 256 bytes of the loader into
      > > memory. The SIMH emulator will boot the Burcon disk just fine if I install the
      > > original Altair boot ROM or the modified Altair32 emulator's boot ROM instead. I
      > > haven't bothered digging into the SIMH boot ROM code yet to find out why.
      > >
      > > Finally, I've written programs to image any Altair floppy to a file on a PC via
      > > a serial port, and the inverse operation to create an Altair floppy from a disk
      > > image file saved on a PC. This program will image any Altair disk independent of
      > > what software created it.
      > >
      > >
      > >
      > > --- In altaircomputerclub@yahoogroups.com, "deramp5113" wrote:
      > > >
      > > > Does anyone have a copy of CPM 2.2 running on an 8800 using the original
      > > Altair floppy drive (88-DCDD)? Ideally, I'd like to see the CBIOS source, but
      > > even a binary version of the whole thing is OK.
      > > >
      > > > The CBIOS written for the Altair32 and Simh emulators, though coded for an
      > > emulation of the 88-DCDD floppy, does not work with a real floppy drive (the
      > > write timing from sector detect to the start of data output is way too long). I
      > > have updated the CBIOS to work with a real drive, but I'm curious how the
      > > "original" versions were coded.
      > > >
      > > > Thanks!
      > > >
      > >
      > >
      > >
      > >
      > > ------------------------------------
      > >
      > > Yahoo! Groups Links
      > >
      >
    • deramp5113
      Yes, you can configure the emulators for a full 64K of RAM and have the 256 byte disk boot ROM actually be RAM so it s bit of space can be used after
      Message 2 of 14 , Feb 2, 2013
      • 0 Attachment
        Yes, you can configure the emulators for a full 64K of RAM and have the 256 byte disk boot "ROM" actually be RAM so it's bit of space can be used after booting.



        --- In altaircomputerclub@yahoogroups.com, "W Tom" wrote:
        >
        > Now that we can capture Altair diskettes, I'd like to run Altair accounting software on an Altair emulator. The Altair accounting software uses BASIC with Memory set to 59000. The software puts printer drivers above BASIC.
        >
        > Do the emulators provide a full 64K RAM after boot like an 8800bt?
        >
        >
        > W Tom S
        > --- In altaircomputerclub@yahoogroups.com, "deramp5113" wrote:
        > >
        > > I'll post an image of a drive or two soon. Sounds like altair32 and simh emulators will update soon to fix disk emulation issues. Simh may host a version of the MITS Burcon disk as well.
        > >
        > >
        > > --- In altaircomputerclub@yahoogroups.com, B Degnan wrote:
        > > >
        > > > Wow that's great. Perhaps you could post the "paper tape" image to the files section? I'd love to try it out.
        > > >
        > > >
        > > >
        > >
        > > >
        > > > -----Original Message-----
        > > > From: deramp5113
        > > > To: altaircomputerclub
        > > > Sent: Wed, Jan 30, 2013 11:14 am
        > > > Subject: [Altair Computer Club] Re: CPM on 8800 using original Altair floppy
        > > >
        > > >
        > > > Status update:
        > > >
        > > > It appears that one of the few, if not the only, version of CPM 2.2 running on
        > > > the original Altair floppy drive (88-DCDD) was "Burcon CPM." I have finished
        > > > creating a fully documented source of the BIOS for the Burcon CPM by
        > > > diassembling a memory dump provided by W Tom.
        > > >
        > > > With the Burcon BIOS source, I can now generate a Burcon CPM of any memory size
        > > > for the Altair disk drive.
        > > >
        > > > There are a couple of minor bugs in the Burcon BIOS, so a slightly modified
        > > > version of the BIOS may also be in order.
        > > >
        > > > The Burcon BIOS, which runs fine on real hardware, did not run under the
        > > > Altair32 or SIMH emulators. After some digging, I found a bug in the floppy
        > > > drive emulation code of both of the emulators. After fixing the bug and
        > > > recompiling the emulators from source, both emulators now work with the Burcon
        > > > disk image.
        > > >
        > > > The SIMH emulator still has a problem in that SIMH's boot ROM won't boot the
        > > > Burcon disk. The loader on the Burcon disk is only two sectors long, but the
        > > > SIMH boot ROM code doesn't properly read the 256 bytes of the loader into
        > > > memory. The SIMH emulator will boot the Burcon disk just fine if I install the
        > > > original Altair boot ROM or the modified Altair32 emulator's boot ROM instead. I
        > > > haven't bothered digging into the SIMH boot ROM code yet to find out why.
        > > >
        > > > Finally, I've written programs to image any Altair floppy to a file on a PC via
        > > > a serial port, and the inverse operation to create an Altair floppy from a disk
        > > > image file saved on a PC. This program will image any Altair disk independent of
        > > > what software created it.
        > > >
        > > >
        > > >
        > > > --- In altaircomputerclub@yahoogroups.com, "deramp5113" wrote:
        > > > >
        > > > > Does anyone have a copy of CPM 2.2 running on an 8800 using the original
        > > > Altair floppy drive (88-DCDD)? Ideally, I'd like to see the CBIOS source, but
        > > > even a binary version of the whole thing is OK.
        > > > >
        > > > > The CBIOS written for the Altair32 and Simh emulators, though coded for an
        > > > emulation of the 88-DCDD floppy, does not work with a real floppy drive (the
        > > > write timing from sector detect to the start of data output is way too long). I
        > > > have updated the CBIOS to work with a real drive, but I'm curious how the
        > > > "original" versions were coded.
        > > > >
        > > > > Thanks!
        > > > >
        > > >
        > > >
        > > >
        > > >
        > > > ------------------------------------
        > > >
        > > > Yahoo! Groups Links
        > > >
        > >
        >
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