CP/M for IMSAI 8080 - CP/M

This is a discussion on CP/M for IMSAI 8080 - CP/M ; I have an IMSAI 8080 with a pair of 8" Discus drives (but no drive cables -- yet). Everything works and memory looks good from the front panel but I have not entered a little loop code to see if ...

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Thread: CP/M for IMSAI 8080

  1. CP/M for IMSAI 8080

    I have an IMSAI 8080 with a pair of 8" Discus drives (but no drive cables --
    yet). Everything works and memory looks good from the front panel but I have
    not entered a little loop code to see if the CPU is working. I need to get a
    bootable floppy. Any ideas on where to look are welcome.

    -- Charlie Springer


  2. Re: CP/M for IMSAI 8080

    On Sep 26, 8:19*am, Charlie Springer wrote:
    > I have an IMSAI 8080 with a pair of 8" Discus drives (but no drive cables--
    > yet). Everything works and memory looks good from the front panel but I have
    > not entered a little loop code to see if the CPU is working. I need to get a
    > bootable floppy. Any ideas on where to look are welcome.
    >
    > -- Charlie Springer


    Hi Charlie
    It has to be specific for your controller. Also, most controllers
    need aROM
    for low level functions. The contrller I have on my machine needs no
    ROM
    since it DMA's a boot sector into RAM on reset. That is then used to
    bootstrap the rest of the disk code and CP/M.
    Most use one of the contrller chips and require some system ROM.
    Dwight

  3. Re: CP/M for IMSAI 8080

    On Sep 26, 10:19*am, Charlie Springer wrote:
    > I have an IMSAI 8080 with a pair of 8" Discus drives (but no drive cables--
    > yet). Everything works and memory looks good from the front panel but I have
    > not entered a little loop code to see if the CPU is working. I need to get a
    > bootable floppy. Any ideas on where to look are welcome.
    >
    > -- Charlie Springer


    As Dwight says, you'd need a CP/M that's been customized for your
    S-100 system. But not only for the floppy controller and drives, but
    for nearly every other board in the machine as well. The problem is
    that simply "IMSAI 8080" says very little about your system's board
    configuration. That you have a working CPA narrows the board
    possibilities down some, but for all you know, as it stands right now,
    it might even not be able to run CP/M at all. A ready-to-go
    bootable CP/M disk for your system very likely doesn't exist now, and
    probably never existed at all.

    I went through the process (with the crucial help of some wonderful
    people on here) of bringing up CP/M from scratch on my own IMSAI...
    and it was an intense, difficult (for me), but very fun and rewarding
    experience.

    JS

  4. Re: CP/M for IMSAI 8080

    On Sun, 28 Sep 2008 08:41:10 -0700, MdntTrain wrote
    (in article
    <6eecd599-4e29-4342-a1f3-19ab566293da@f36g2000hsa.googlegroups.com>):

    > As Dwight says, you'd need a CP/M that's been customized for your
    > S-100 system. But not only for the floppy controller and drives, but
    > for nearly every other board in the machine as well. The problem is
    > that simply "IMSAI 8080" says very little about your system's board
    > configuration. That you have a working CPA narrows the board
    > possibilities down some, but for all you know, as it stands right now,
    > it might even not be able to run CP/M at all. A ready-to-go
    > bootable CP/M disk for your system very likely doesn't exist now, and
    > probably never existed at all.
    >
    > I went through the process (with the crucial help of some wonderful
    > people on here) of bringing up CP/M from scratch on my own IMSAI...
    > and it was an intense, difficult (for me), but very fun and rewarding
    > experience.


    I want to give it a good try. I have plenty of competence with hardware from
    that general time except I was all 6502 embedded in instrumentation.

    The IMS I.A. Box is S# 1009668

    Anyway, the processor card is a bare bones 8080A card. There are two loaded
    memory cards, and a George Morrow design disk controller called a "Disk
    Jockey 2D/B" which is a 1980 design.

    I'll upload pictures tomorrow to Tinypic and see if anyone has any ideas.

    -- Charlie Springer


  5. Re: CP/M for IMSAI 8080

    "Charlie Springer" wrote:

    > I want to give it a good try. I have plenty of competence with hardware

    from
    > that general time except I was all 6502 embedded in instrumentation.


    Me, it is the reverse: I have plenty of competence with software, but I
    found that it was not enough when I tried to understand the BIOS of CP/M-86
    Plus.

    So far, nobody mentioned that, at the time, several books explained how to
    write a BIOS (something that I have never seen for the IBM Clown: my problem
    is that the BIOS of CP/M-86 Plus was written for a PC XT, and it does not
    boot (from the Hard Disk) on a PC AT. So, somewhere, something changed, but
    what?).

    As far as I know, the best book is:

    - "The Programmer's CP/M Hand Book"
    Andy Johnson-Laird
    McGraw-Hill, 1983

    (I remember that someone recently got the code. But I don't remember where
    it is to be found.)

    Yours Sincerely,
    Mr. Emmanuel Roche, France




  6. Re: CP/M for IMSAI 8080

    "Mr. Emmanuel Roche, France" wrote:

    > (I remember that someone recently got the code. But I don't remember where
    > it is to be found.)


    Found it! Go to http://www.cpm.z80.de/source.html then go down to the
    bottom.

    Yours Sincerely,
    Mr. Emmanuel Roche, France





  7. Re: CP/M for IMSAI 8080

    On Wed, 01 Oct 2008 10:50:44 +0200, Mr. Emmanuel Roche, France wrote:

    ....
    > So far, nobody mentioned that, at the time, several books explained how
    > to write a BIOS (something that I have never seen for the IBM Clown: my
    > problem is that the BIOS of CP/M-86 Plus was written for a PC XT, and it
    > does not boot (from the Hard Disk) on a PC AT. So, somewhere, something
    > changed, but what?).

    ....

    The original IBM PC came with a commented source code listing of the BIOS,
    there never was a need for some such book. You would use the IBM
    specification to write an BIOS, same as everyone else did. A PC AT
    requires a different BIOS of course, because lots was changed.

    Udo Munk
    --
    The real fun is building it and then using it...


  8. Re: CP/M for IMSAI 8080

    On Oct 1, 2:23 am, Charlie Springer wrote:

    > The IMS I.A. Box is S# 1009668
    >
    > Anyway, the processor card is a bare bones 8080A card. There are two loaded
    > memory cards, and a George Morrow design disk controller called a "Disk
    > Jockey 2D/B" which is a 1980 design.
    >
    > I'll upload pictures tomorrow to Tinypic and see if anyone has any ideas.
    >
    > -- Charlie Springer


    The Morrow DJ 2D/B is a somewhat common S-100 floppy disk controller
    board. The manual for that and other models of Morrow controllers
    includes a source listing of the BIOS, maybe the BOOT as well. Be sure
    to get the 2D/B manual, there were other DJ 2D models. Chances are
    someone has one of these running and can provide a diskette. You will
    likely need a 4MHZ 8080 or Z80, I've not looked at this card or manual
    lately.

    Obtain and read the manual to see what you need. ***Read the
    manual.*** ***Read the manual***

    Find the manual at the usual venues on the Web for S-100 manuals,
    including mine.

    Herb Johnson
    retrotechnology.com

  9. Re: CP/M for IMSAI 8080


  10. Re: CP/M for IMSAI 8080

    On Oct 1, 9:15*pm, Charlie Springer wrote:

    > I need ANY docs and disks for a Rockwell System65.

    ----
    I've got some brochures etc. for some of the RM65 and VME stuff
    somewhere; not very informative or useful, but I suppose I could scan
    it for general interest's sake. I may know someone with a bit more
    though; PM me off-list if interested.

    I also have a few AIM65s; let me know when you've got CP/M running on
    it ;-)

    mike


  11. Re: CP/M for IMSAI 8080

    *Mr. Emmanuel Roche, France* wrote on Wed, 08-10-01 10:50:
    >So, somewhere, something changed, but what?).


    http://www.nostalgia8.nl/mirrors/cpm86/patch.htm
    http://www.cpm.z80.de/binary.html
    http://newsgroups.derkeiler.com/Arch.../msg00063.html
    Paradox concerning CP/M-86

    No, I haven't read them all and you could go and google for the "AT-
    patch" yourself.


  12. Re: CP/M for IMSAI 8080

    On Thu, 2 Oct 2008 04:09:12 -0700, MikeS wrote
    (in article
    ):

    > I also have a few AIM65s; let me know when you've got CP/M running on
    > it ;-)


    There was a board by a Southern California users group (RACK?) that plugged
    into the 6502 socket and had a Z80 and CP/M.

    -- Charlie


  13. Re: CP/M for IMSAI 8080


    IMS MPU-A Rev-4 1975 8080A

    Disk Jockey 2D/B FDC with RS232 from Morrow

    S. C. Digital Model-32KUS Rev B 8/16 bit 32K of 6116 static RAM.
    'UNISELECT:3'

    Seals Electronics 16K Static RAM

    Two Discus drives and no cable.

    So, 48K RAM, CPU, FDC and terminal I/O. Sounds like a full course meal.

    What do I need to get going?

    -- Charlie Springer


  14. Re: CP/M for IMSAI 8080

    On Thu, 2 Oct 2008 18:14:19 -0700, Charlie Springer
    wrote:

    >
    >IMS MPU-A Rev-4 1975 8080A
    >
    >Disk Jockey 2D/B FDC with RS232 from Morrow
    >
    >S. C. Digital Model-32KUS Rev B 8/16 bit 32K of 6116 static RAM.
    >'UNISELECT:3'
    >
    >Seals Electronics 16K Static RAM
    >
    >Two Discus drives and no cable.
    >
    >So, 48K RAM, CPU, FDC and terminal I/O. Sounds like a full course meal.
    >
    >What do I need to get going?
    >
    >-- Charlie Springer


    A BIOS for that hardware mix (DJ controler with IO). Seems like a
    trivial thing but you need CP/M on media to mach your physical drives
    and the controller used. Without that you cooking from raw.

    Allison


  15. Re: CP/M for IMSAI 8080

    On 10/3/08 1:09 PM, in article obkce414sfk6576k2kqchcsugh02s76e5e@4ax.com,
    "no.spam@no.uce.bellatlantic.net" wrote:

    > On Thu, 2 Oct 2008 18:14:19 -0700, Charlie Springer
    > wrote:
    >
    >>
    >> IMS MPU-A Rev-4 1975 8080A
    >>
    >> Disk Jockey 2D/B FDC with RS232 from Morrow
    >>
    >> S. C. Digital Model-32KUS Rev B 8/16 bit 32K of 6116 static RAM.
    >> 'UNISELECT:3'
    >>
    >> Seals Electronics 16K Static RAM
    >>
    >> Two Discus drives and no cable.
    >>
    >> So, 48K RAM, CPU, FDC and terminal I/O. Sounds like a full course meal.
    >>
    >> What do I need to get going?
    >>
    >> -- Charlie Springer

    >
    > A BIOS for that hardware mix (DJ controler with IO). Seems like a
    > trivial thing but you need CP/M on media to mach your physical drives
    > and the controller used. Without that you cooking from raw.


    I went through this process with the tremendous help of John (also on this
    thread). If you look on my IMSAI System page
    (http://www.classiccmp.org/cini/my_imsai.htm) I outline the process. My
    problem is that I didn't have a system disk for the combination of hardware
    I had.

    First, it sounds like you need a cable. I know nothing about the Discus
    drives, but if it's using a Morrow controller, it's probably 50-pin IDC
    cable in some form or fashion.

    The second element of doing a "virgin birth" CP/M setup is a working
    "monitor" program in ROM that can load Intel HEX files. It doesn't look like
    you have a ROM/EPROM board, but you might be able to use the 6116 board as
    the 6116 has a pinout compatible with the 2716 EPROM. I used a CompuPro
    RAM17 which also uses 6116 SRAM chips, and I replaced the RAM at $F000 with
    a 2716 and it works fine.

    This monitor will also contain the raw disk access routines. Maybe the
    DJ2D/B has a ROM on board (I don't remember) that contains the access
    routines that you can call from the CP/M CBIOS you are going to build and
    store in your EPROM.

    Rich




  16. Re: CP/M for IMSAI 8080

    On Fri, 3 Oct 2008 18:50:42 -0700, Richard A. Cini wrote
    (in article ):

    > This monitor will also contain the raw disk access routines. Maybe the
    > DJ2D/B has a ROM on board (I don't remember) that contains the access
    > routines that you can call from the CP/M CBIOS you are going to build and
    > store in your EPROM.


    Thanks Rich. I will look at your page. I have been saving pages by printing
    as PDF. The DJ has a ROM and does auto-boot, or reset is vectored to the DJ
    ROM automatically. It shouldn't be too hard to get my hands on the big ribbon
    cable. You can do those connectors with a vice and I have some 50's in my
    parts supplies ( Stanley-Vidmar parts cabinets - talk about the Cadilac of
    storage! If anyone needs an obscure part, ask me first since I can give most
    away. Need a full reel of 1N4001 diodes?) but maybe someone has some ready
    made with appropriate spacing to daisy chain a couple of drives.

    -- Charlie Springer


  17. Re: CP/M for IMSAI 8080

    Richard A. Cini wrote:

    > I went through this process with the tremendous help of John (also on this
    > thread). If you look on my IMSAI System page
    > (http://www.classiccmp.org/cini/my_imsai.htm) I outline the process. My
    > problem is that I didn't have a system disk for the combination of hardware
    > I had.


    Thanks for creating that webpage. It will be a great help when I find
    the time to restore my IMSAI.


    --
    David Griffith
    dgriffi@cs.csbuak.edu <-- Switch the 'b' and 'u'

  18. Re: CP/M for IMSAI 8080

    On Sep 26, 10:19 am, Charlie Springer wrote:
    > I have an IMSAI 8080 with a pair of 8" Discus drives (but no drive cables --
    > yet). Everything works and memory looks good from the front panel but I have
    > not entered a little loop code to see if the CPU is working. I need to get a
    > bootable floppy. Any ideas on where to look are welcome.
    >
    > -- Charlie Springer


    Have you found a copy of the Manual
    Herb Johnson has one.
    I sent the files to Jack Rubin but having the Manual would help get a
    correct Bios Built.
    Has anyone out there a copy of the BOOT Floppy.
    I sent the one I had to whomever I sold the DJ to but Can't remeber
    who.
    The copies I made don't hve the Boot Tracks on zero & one.
    Bob in Wisconsin

  19. Re: CP/M for IMSAI 8080

    On Wed, 15 Oct 2008 11:40:50 -0700, BrightFame wrote
    (in article
    <15e01fca-77d8-4c89-8ea8-c26483bebda6@k37g2000hsf.googlegroups.com>):

    >
    > Have you found a copy of the Manual
    > Herb Johnson has one.
    > I sent the files to Jack Rubin but having the Manual would help get a
    > correct Bios Built.
    > Has anyone out there a copy of the BOOT Floppy.
    > I sent the one I had to whomever I sold the DJ to but Can't remeber
    > who.
    > The copies I made don't hve the Boot Tracks on zero & one.
    > Bob in Wisconsin


    I downloaded files and PDFs from Richard's (?) web site and have not looked
    them over yet. I think Jack is going to forward anything useful.

    -- Charlie Springer


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