PL/M & CP/M

dwight dkelvey at hotmail.com
Tue Jun 7 12:57:59 CDT 2022


I'm relatively sure PL/M was written by Gary Kildall.
I believe it was originally used on minis ( not sure which one ) but was later ported to the 8080 under ISIS. One might notice the similarities of ISIS to CP/M.
Dwight

________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Chuck Guzis via cctalk <cctalk at classiccmp.org>
Sent: Tuesday, June 7, 2022 9:05 AM
To: Hector Peraza via cctalk <cctalk at classiccmp.org>
Subject: Re: PL/M & CP/M

On 6/7/22 00:30, Hector Peraza via cctalk wrote:

> In the late 80's I disassembled a PL/M compiler I got in paper tape and
> ported it to CP/M. Then stored it in a cassette tape, then lost it, then
> about 8 years ago found it again and recovered it. The compiler had no
> indication whatsoever of who wrote it, but with the help of Mr. Emmanuel
> Roche from comp.os.cpm it's origin was traced back to Norsk Data's
> PL/Mycro compiler for their Mycro-1 8080 machine. It is a one-pass
> compiler (the key to its identification), appeared to be written
> directly in 8080 assembly, and produces hex or binary output. I never
> made it available anywhere, except for the copy I gave to Mr. Roche and
> IIRC to Mark Ogden too. Is that the one you mean? The only other PL/M
> compiler I know about that ran on 8-bit hardware, besides Intel's, was
> PLMX but I don't now the history behind it.
>
Back in the late 70s I sampled (for my employer) MP/M 1.0.  One of the
things that came with the OEM kit was DRI's PL/I compiler.  I'd become
acquainted with PL/I under DOS/360 and was surprised to see PL/I for 8
bit machines.  What was most surprising was that it was a pretty
complete D-level implementation on the 8080 (I ran it on 8085),
including the preprocessor (I can recall wishing that C had a similarly
capable preprocessor back then--not just a bunch of conditionals and the
#define statement).

I recall that DRI at the time was pushing its ISV program, with the hope
that PL/I might be sufficiently platform-independent.

--Chuck


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