[TUHS] Terak Mini-UNIX

[John Foust via TUHS]

Claude and I analyzed the Terak-Unix at Bitsavers 
https://bitsavers.trailing-edge.com/bits/Terak/mini-unix/.

The Terak Unix on Bitsavers is based on Heinz Lycklama's MINI-UNIX 
(Bell Labs, 1977: UNIX Sixth Edition for PDP-11s without memory management), 
ported to the Terak 8510/a's QX floppy controller.

Aado Perandi, a graduate student at the University of Minnesota, built 
the first Terak UNIX in spring 1979.  It was described in the University 
Computing Center's newsletter in May 1979.  The work was done on
a PDP-11/40 running Unix V6 and copied to ten Terak 8" floppies, IBM 3740 SSSD.
The C is V6, the libraries using the newer archive format from PWB V7.

Perandi's modifications were lost in a disk failure that summer and he left; 
Marc G. Smith at SICL (the Special Interactive Computations Laboratory within
the Space Science Center), redeveloped it from "mostly from scratch"
and was still distributing floppies in April 1980.

A troublesome flaw is that the swap area is kept on the boot floppy
but the Terak hardware did not have any disk-changed notification.  
If you removed the boot floppy from the boot drive and inserted another 
and then the system swapped, it would write over whatever was on 
the second floppy.  Many of the disks images on Bitsavers show this.

Claude decompiled the binaries and restored them as C source, compared 
against the MINI-UNIX source, determined the changes that Smith made
and the other Terak-unique parts, compiled it all again within my 
Terak emulator, rebuilding the kernel in a minute, and confirmed 
everything matches to the byte.

I will pass my repairs to Bitsavers as soon as I figure out how to do that.

Perandi and Smith are still around, I reached out but haven't had a response.

>From my own perspective, I'm puzzled as to why this UNIX didn't 
make it to UW-Madison's Teraks as far as I remember.  The interest
was certainly there; I remember an elite hacker who crafted a Unix-alike 
under the UCSD p-System, with a shell that ran p-System executables with 
short names.  Perhaps it was the cost of ten floppies and student programmers
were broke back then.

- John