[Simh] MagicSix

Phil Budne phil at ultimate.com
Fri Nov 9 21:35:22 EST 2018


> Has there been any attempt to locate the operating system MagicSix

Larry Stewart wrote:

    As far as bits go, I don't have any, although I do have some
    hand-drawn schematics of the color display I built for the
    Interdata model 85 and my old undergrad thesis (color printing).

Andy Lipman forwarded my query to Gregory Steve & Paul Mockapetris
with the prefix "Any ideas for this poor soul?"

Paul Mockapetris wrote:

    I have a few shards of the Magic operating system somewhere, but
    not nearly enough to make anything interesting run.  I don't know
    if there's any history or photos from the era.  If anyone has any,
    I'd love to get them.

    My recollection of the history is that Nicholas forbade any OS
    work.  So naturally, while he went off for a summer in Patmos, we
    built one.

    Alternatively, since the Architecture machine was not famous or
    funded enough at the time, the resources we had were a limited
    amount of CPU time donated by the IBM Cambridge Scientific Center,
    some Interdata minicomputers, and a hard drive..  So as I remember
    it, Steve Gregory and I started some software, while Andy and
    perhaps Mike did the disk controller and shared I/O bus.  We
    called the system Magic for Mockapetris and Gregory's Interactive
    Computer, since we couldn't build an operating system

    Magic 1.0 allowed basically a user per machine with a shared fail
    system.

    While ludicrous by today's standards, it was probably state of the
    art at the time.  We could easily have published in the computer
    science journals of the time, if only we had known we were being
    cool rather than practical.

    I remember Jim Taggart had some software he was working on that he
    would keep on multiple paper tapes of source code, then debug and
    accumulate paper tapes of patches, and then go back and redo the
    source and rebuild.  The editing and compiling and linking meant a
    new build from source would take a couple days or more.  Once we
    had Magic working, Jim could rebuild in 40 minutes or so, mostly
    with his feet up as the system grinded away.  He was our biggest
    defender when Nicholas came back from Patmos.  (I also seem to
    remember a huge sigh of relief when we got the ability to back up
    the Magic disk drive to mag tape, after I had been backing it up
    illicitly to an IBM timesharing system via a terminal emulation a
    scheme at 15 or so characters per second)

    I believe this was the summer of 69 or maybe 70.  I was off after
    that,

    Anyway, I remember that this stone age stuff was replaced by
    bronze or iron age versions.  I seem to recall Magic 6.0 with 32
    bit architecture and a PL/1 compiler, but somebody else will have
    to tell that story.


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