One version (mine) contains a 67mb harddrive, 2mb ram, a 5 and 1/4 inch floppy, and that's about it. Supposedly it can be hooked into ethernet, but I am yet to succeed. The keyboard fits nicely onto the top of the box, and the moniter is attached just behind that. It runs SystemV, and supposedly can compile PERL in about 14 hours. Ohio University has a lot of resources for anyone interested.
From the FAQ of comp.sys.3b1:
"The name "UNIX PC" is a catch-all name for a set of machines
developed by Convergent Technologies (now part of Unisys) and sold by
AT&T in the mid to late 80's, all having the same basic configuration:
o 10MHz 68010 with custom MMU
o demand paged, virtual memory UNIX (max. process size 2.5M)
o 10/20/40/67MB disk
o 512k/1M/2MB RAM
o monochrome, quasi-Hercules display
As marketing strategies changed and basic features were added,
the original offering (the PC7300) became known as the 3B1. The 7300
machines featured 512k RAM on the motherboard with a 10 or 20MB disk.
The later 3B1 machines had 1M or 2M on the motherboard, and came with
a 40 or 67MB disk. Accommodating the larger, full-height drives in the
3B1 required that a hump be added to the sloping, wedge-shaped case
top. The 3B1 also has a heftier power supply."
I would be playing nethack on mine now, but unfortunately the floppy disk controller will not recognize anything above a 760k drive, which i can find none of. :-(
The chief data transmission protocol used by these machines is UUCP. They use a window manager called MGR to actually support a GUI.
On the high end model, the drive heads park themselves, but on the lower end models they have to be manually parked by booting from a special floppy before transporting the box.
This is about all I know about them, but with a little searching you should be able to find out more.