[TUHS] PC Unix

heinz at osta.com heinz at osta.com
Thu Apr 8 01:57:28 AEST 2021

Yes, that sounds about right. LSX and MX used older versions of UNIX
and binary licensing from WE was not yet available.


On 2021-04-07 00:52, Paul Ruizendaal via TUHS wrote:
>> 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
>> 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?

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