Care and feeding of some Lisp machines (TI Explorer and Xerox Star)

null ian.finder at
Mon Sep 14 13:34:21 CDT 2020

Regarding the mouse- it is a black Mouse Systems optical mouse, terminated in a two row IDC connector.

If desired, I can take internal pictures and send along the pinout. Let me know.

> On Sep 14, 2020, at 09:01, Josh Dersch via cctech <cctech at> wrote:
> On Mon, Sep 14, 2020 at 6:35 AM Michael Engel via cctech <
> cctech at> wrote:
>> Hi,
>> for a planned exhibition, I am thinking of restoring two of the machines
>> to working state again that are in storage here for decades:
>> - A TI Explorer ("Sperry" labeled)
>> and
>> - A Xerox Star (no idea if ours actually ran Interlisp or one of the
>> other OSes for the Star/Dandelion)
>> There is "sen´s dandelion restoration blog" at
>> (which seems to be very helpful to test the power supply) and, of
>> course, lots of documents and software on bitsavers. I have quite a bit
>> of experience with TI1500 machines, so the Explorer feels rather
>> familiar, but I have never worked with Xerox machines before.
>> Before I start to disassemble and test the machines, I would be
>> interested to hear about specific problems you might have experienced
>> bringing up one of these two machines, preferably those on the
>> unexpected side.
>> Some things I could not find so far are the mouse and the console cable
>> for the Explorer. It seems that the mouse is related to MouseSystems
>> optical mice used on older Sun/SGI systems (but the interface might be
>> different?). The fiber optics cable for the display (TI part number
>> 2233200 according to the field service manual) might be another problem
>> - if you know any details about this, I would be very interested...
>> Another thing that is also missing is the mouse pad for the three button
>> optical Xerox mouse. Is it possible that an optical mouse pad for
>> Sun/SGI machines is compatible?
>> Best wishes,
>>     Michael
> I've restored a Star/1108 (and wrote a Star emulator) and am in the middle
> of an Explorer restoration, I'm happy to help out where I can.
> I'd recommend picking up an MFM Emulator (
> along with the SA1000 adapter for same, for use with the Star.  The
> original disks are getting more difficult to keep running, and it's also a
> lot more convenient for switching between different operating systems, etc.
> Remove the sound-deadening foam from the panels of the system, it's getting
> crumbly and isn't going to do you any favors to leave it in place.  I've
> found the power supplies to be fairly reliable.  One issue is weak picture
> tubes in the displays -- the monitors are powered on with the system and
> have no separate off switch, so they tended to get a lot of hours put on
> them.  We had good luck with a tube rejuvenator on the one we restored at
> LCM.
> The Star mouse pad can be recreated with a laser printer (I've used this:
>, and
> there's a postscript file floating around out there...).  Or any surface
> with a fine pattern on it seems to work pretty well; I was able to make it
> work on a speckled countertop and the pant leg of my jeans at one point.
> It's a lot more forgiving than the Sun mice which need the fixed grid of
> the metal mouse pads.
> For the Explorer, there are a number of r fa line filter caps in the
> system, on the power supply board as well as on a separate board near the
> rear of the chassis.  I suggest replacing these immediately as they like to
> let out smoke.  The optical cable is extremely rare and despite some
> valiant efforts we haven't found an equivalent, or new-old-stock
> replacements.  A friend of mine is working on retrofitting modern optics,
> and has made some great progress.  The mouse is indeed a standard Mouse
> Systems, I'm missing mine at the moment and haven't yet gotten to the point
> of adapting a mouse to replace it.  I suspect it's equivalent to the M2
> used on the Sun-2 and LMI Lambda systems.
> Media for the Explorer is another question that I'm hoping to answer soon.
> There are disk images from the Meroko emulator but my understanding is that
> they are incomplete.  Bitsavers has QIC tape images but I have yet to try
> them.  The interface on the Explorer is SCSI but I haven't had luck booting
> it from a SCSI2SD w/Meroko images loaded.  The disk boxes contain an Emulex
> SCSI->MFM bridge, so use of Dave's MFM emulator might make sense here as
> well.
> If you have disks in your Explorer, let me know -- capturing an image of
> their contents would be extremely useful, and the original Maxtor drives
> are not long for this world.
> Hope that helps a bit, happy to answer any questions... or try anyway.
> - Josh

More information about the cctech mailing list