Uncrating of Symbolics "MacIvory" Machine

At long last, got hold of one of these:



This entry was written by Stanislav , posted on Monday December 17 2018 , filed under Computation, Hardware, Lisp, LispMachine, MacIvory, Photo, ShouldersGiants, SoftwareArchaeology, Symbolics . Bookmark the permalink . Post a comment below or leave a trackback: Trackback URL.

6 Responses to “Uncrating of Symbolics "MacIvory" Machine”

  • Simon says:

    Woooh yeah!

  • alex says:

    Very cool. Did this come from DKS or second hand? I'd be very interested to know if they were still shipping these units.

    I saw in an earlier post you were using the VLM on an alpha workstation. How does the experience compare?

    I was able to get that leaked VLM code to compile and run again on modern linux, and am undertaking a proper exploration of Genera. It seems like all it's made out to be, and I would love to make it my daily computing platform, but the underlying emulator is unstable (I can't save a world without it crashing, for instance), and the lack of a proper symbolics keyboard is very limiting.

    Hopefully I can track down why save world doesn't work (probably display protocol issues) patch it, and get to work, but even if I succeed, I'm starting to think I should just pick up a MacIvory board.

    • Stanislav says:

      Dear Alex,

      It's from DKS. It is my understanding that he no longer has a regular stockpile of these; but every other year or so, he digs one up and puts it for sale.

      VLM on Linux is indeed known to be unstable (the exact reason, is not presently known to me.) The orig. Alpha ver. is considerably more reliable.

      The Symbolics keyboard impresses novices but IMHO is actually quite unpleasant to use -- not only no "click", but pre-dates the introduction of arrow keys. At one time I owned two (one "old"-style, the other "new"), and in 2008, built a PC adapter for them; but since gave both away, and not interested in buying any again.

      Probably I ought to add that I bought the box pictured above not for battlefield use, as such, but for reversing. I've begun to slowly milk the schematic out of the PCBs; later on will reverse the PALs/GALs; and at some later time will get the Ivory IC properly microscopied. Aim is to build a functioning cycle-accurate clone.


  • alex says:


    This is excellent news. I'm impressed that you are willing to so thoroughly violate this machine in order to publish it's secrets, although, being familiar with your earlier essays, perhaps I should not be so surprised. Honestly, I think I would hesitate. I would like to think I would get down to doing this work once the lispm novelty wore off, but I am not so sure. I wish you the best of luck.

    Lacking a physical lispm, I actually started digging into the VLM code with similar intentions before letting myself get sidetracked into hacking Genera. I wanted to learn about the Ivory architecture, produce a better-written software emulator, and (more abitiously for me) reproduce something in an HDL. While there are some world file format differences between the I-machines and VLM, the compiler and resulting machine code are, to my knowledge, the same, and so I reasoned that a working replica could be made given knowledge of the machine code, the emulator's internal CPU representation, and the U-code, the lattermost of which I regrettably do not have. The Ivories weren't nearly as radical a departure from conventional computer architecture as your dataflow CPU would be.

    Of course, the result wouldn't really be an Ivory, and would probably be more effort in the end than your direct approach.

    My VLM keyboard woes are probably more to do with the silly HHKB I'm using, which feels great to my fingers and works fine for my usual emacs/slime workflow, but whose lack of un-modified F keys is now a serious impediment.

    I think I've isolated the problem with Save World, shooting to push a patch and get back to my original task this week... It's quite clear to me that his task would have been much more difficult without an integrated debugger, incremental recompilation, who-calls, etc.

    • Stanislav says:

      Dear Alex,

      FWIW I sawed on the Alpha emulator in IDA for years, summing to no particularly noteworthy result. Then found the leaked source (apparently various people have been passing it back and forth for many years and no one saw it fit to let me know..) and indeed it is not a complete picture of the thing. Which is why some hardware archaeology is called for IMHO.

      Soon I expect to have x-ray photos of the PCBs, incidentally.

      > The Ivories weren’t nearly as radical a departure from conventional...

      My intention is not to build a "Ivory on steroids" -- it is an arch that suffered many warts given the transistor-poverty of its era -- but to preserve the software stack for study. (It must be runnable on iron which remains available, and there are not so many actual Ivories remaining in working condition.)

      It is my position that a sane computing system cannot be built without detailed study of the state of the art -- which to this day remains Symbolics, rather than the layered piles of shit offered by the past 25 years of consumer market.


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