Unix on 370's

[Alex Nishri]

An AT&T representative at SHARE (the IBM large mainframe user's group) a year
ago gave a talk about UNIX for IBM/370 architecture computers.  He said that
AT&T hired IBM to hack up TSS to be used as the 'virtual computer' bottom
layer to UNIX.  This simplified porting of UNIX.  (Most IBMers had assumed
assumed that TSS, a very old system from the distant past,  had long
since been forgotten.)  AT&T also got IBM to write new software for a
standard IBM front end computer.  IBM front end computers generally only
support terminals in half-duplex, but this new code allowed full-duplex.

The person giving the presentation said that once somebody at Bell Labs was
moved to the IBM hardware they refused to go back to anything else.  Apparently
the most impressive thing about IBM hardware was the over 98% reliability.
Another feature was the faster compile time on the bigger machines.

The presenter said that the Unix for 370 machines was available (for a fee)
from AT&T, but that the reels of tape you got would be useless because
IBM refuses to release their hacked up TSS and front end software that goes
along with this software (outside of Bell itself).  (Many people hissed
but that has not helped change IBM's mind ... but then many people could not
understand why AT&T used TSS and not VM and that did not help either.)

Amdahl's Unix for 370 machines (known as UTS) also uses a bottom layer to
simplify porting, but it uses VM/370 (or VM/SP) a very common and supported
operating system.  UTS will apparently be able to run native very soon (if
it doesn't already.)  UTS also uses existing front end computer software and
thus is half-duplex.   (There are some ways to give the illusion of full-duplex
but they are not very satisfying.)

Anyone requiring specific references, names, etc can send me mail.  I still
have the notes that I took.

What I would be curious to know -- is there any AT&T Unix running on an
IBM/370XA machine yet?

Alex Nishri
University of Toronto
  ... utcsstat!nishri