PC Unix - TUHS

7 Apr 2021

...
  I developed LSX at Bell Labs in Murray Hill NJ in the
1974-1975 
 timeframe.
 An existing C compiler made it possible without too much effort. The 
 UNIX
 source was available to Universities by then. I also developed Mini-UNIX
 for the PDP11/10  (also no memory protection) in the 1976 timeframe.
 This source code was also made available to Universities, but the source
 code for LSX was not.

 Peter Weiner, the founder of INTERACTIVE Systems Corp.(ISC) in June 
 1977,
 the first commercial company to license UNIX source from Western
 Electric for $20,000. Binary licenses were available at the same time.
 I joined ISC in May of 1978 when ISC was the first company to offer
 UNIX support services to third parties. There was never any talk about
 licensing  UNIX source code from Western Electric (WE) from the founding
 of ISC to when the Intel 8086 micro became available in 1981.
 DEC never really targeted the PC market with the LSI-11 micro,
 and WE never made it easy to license binary copies of the UNIX
 source code, So LSX never really caught on in the commercial market.
 ISC was in the business of porting the UNIX source code to other
 computers, micro to mainframe, as new computer architectures
 were developed.

 Heinz 
The Wikipedia page for ISC has the following paragraphs:

"Although observers in the early 1980s expected that IBM would choose Microsoft Xenix
or a version from AT&T Corporation as the Unix for its microcomputer, PC/IX was the
first Unix implementation for the IBM PC XT available directly from IBM. According to Bob
Blake, the PC/IX product manager for IBM, their "primary objective was to make a
credible Unix system - [...] not try to 'IBM-ize' the product. PC-IX is System
III Unix." PC/IX was not, however, the first Unix port to the XT: Venix/86 preceded
PC/IX by about a year, although it was based on the older Version 7 Unix.

The main addition to PC/IX was the INed screen editor from ISC. INed offered multiple
windows and context-sensitive help, paragraph justification and margin changes, although
it was not a fully fledged word processor. PC/IX omitted the System III FORTRAN compiler
and the tar file archiver, and did not add BSD tools like vi or the C shell. One reason
for not porting these was that in PC/IX, individual applications were limited to a single
segment of 64 kB of RAM.

To achieve good filesystem performance, PC/IX addressed the XT hard drive directly, rather
than doing this through the BIOS, which gave it a significant speed advantage compared to
MS-DOS. Because of the lack of true memory protection in the 8088 chips, IBM only sold
single-user licenses for PC/IX.

The PC/IX distribution came on 19 floppy disks and was accompanied by a 1,800-page manual.
Installed, PC/IX took approximately 4.5 MB of disk space. An editorial by Bill Machrone in
PC Magazine at the time of PC/IX's launch flagged the $900 price as a show stopper
given its lack of compatibility with MS-DOS applications. PC/IX was not a commercial
success although BYTE in August 1984 described it as "a complete, usable single-user
implementation that does what can be done with the 8088", noting that PC/IX on the PC
outperformed Venix on the PDP-11/23.”

It seems like Venix/86 came out in Spring 1983 and PC/IX in Spring 1984. I guess by then
RAM had become cheap enough that running in 64KB of core was no longer a requirement and
LSX and MX did not make sense anymore. Does that sound right?