Honeywell Bull XPS-100

A big fat Bull XPS-100
  • Make: Honeywell Bull (actually designed by Honeywell Information Systems Italia)
  • Model: XPS-100 model 25
  • CPU/FPU: Motorola 68020/68881
  • RAM: 10 MB (4+4+2)
  • Storage: 2x 325(?) MB ESDI hard disks; 1x 1.2MB 5.25" floppy; 1x 150MB QIC tape
  • Manufactured: 1980s
  • Acquired: 1996 from Southern Records via DKB
  • Sold: 2003 via Ebay
  • Measurements: 38(w) x 72(d) x 71(h) cm (15" x 28" x 28" approx)
  • OS: Bull HN Unix (SVR3 derivative). Fresh install from tape and floppy.


Large, heavy, extremely robust VME chassis. Weight is significantly more than sarotti, but most of the contents can be dismantled and removed for easier transport.

There are fixed rollers on the base instead of directional castors, because no castor would be strong enough to hold the weight. The shell is extremely robust -- the best advert for this is the fact that you can stack these beasts on top of one another (assuming you can lift them) and they don't bend.

As well as the PSU fans there is a fan "blade" with 6 large high-speed fans for system cooling. Noise levels can be high.


Front panel has "soft" power-on/shutdown and cool-looking 2-digit matrix-LED readout which shows mystical numbers during boot and elsewhen. No-one is entirely sure what they mean. EIGHT 9-pin serial ports, AUI ethernet, connectors for UPS and "Unat Syst" (?) and funky slot-in boot PROM. Twin PSUs for total of 1.5kW. Model 40 variant consisted of two full-size units conjoined side-by-side via an umbilical access hatch.


Bull Front Naked Bull Back Naked Bull Bull Control Panel Bull PSUs Bull Tape Drive Bull Umbilicus


I did a fresh install of the Bull Unix OS onto this machine from tape and floppy when I first got it. I managed to get the tapes back from bjh in the nick of time to pass them on to jimbowen's next happy owner.

bjh compiled some useful GNU software for the Bull, which is still available on Mono, along with the installation guide I wrote at the time.

The large amount of diskspace on this machine made it quite useful as a server for a while, but it hasn't been used for some time now and I no longer have a suitable serial cable to test it properly. The front-panel boot numbers are embedded into my consciousness though, and it appears to show all the right ones in the right order so chances are high that it's fully functional.