From: Paul Ruizendaal via TUHS <tuhs@minnie.tuhs.org>
To: TUHS main list <tuhs@minnie.tuhs.org>
Subject: [TUHS] PC Unix (had been How to Kill a Technical Conference
Date: Sat, 10 Apr 2021 20:12:29 +0200 [thread overview]
Message-ID: <C0701400-5508-48B6-927E-C3B2E8658588@planet.nl> (raw)
[-- Attachment #1: Type: text/plain, Size: 2936 bytes --]
> On Fri, Apr 9, 2021 at 11:34 PM Ed Bradford <egbegb2 at gmail.com <https://minnie.tuhs.org/cgi-bin/mailman/listinfo/tuhs>> wrote:
>
> > Why did a Ph.D., an academic, and a computer scientist not know about UNIX
> > in 1974 or so? 1976? In 1976, some (many?) universities had source code.
> >
>
> Some knowns/givens at the time ...
> 1.) He was a language/compiler type person -- he had created PL/M and that
> was really what he was originally trying to show off. As I understand it
> and has been reported in other interviews, originally CP/M was an attempt
> to show off what you could do with PL/M.
> 2.) The 8080/Z80 S-100 style machines we quite limited, they had very
> little memory, no MMU, and extremely limited storage in the 8" floppies
> 3.) He was familiar with RT/11 and DOS-11, many Universities had it on
> smaller PDP-11s as they ran on an 11/20 without an MMU also with limited
> memory, and often used simple (primarily tape) storage (DECtape and
> Cassette's) as the default 'laboratory' system, replacing the earlier PDP-8
> for the same job which primarily ran DOS-8 in those settings.
> 4.) Fifth and Sixth Edition of Unix was $150 for university but to run it,
> it took a larger at least 11/40 or 45, with a minimum of 64Kbytes to boot
> and really need the full 256Kbytes to run acceptably and the cost of a 2.5M
> byte RK05 disk was much greater per byte than tape -- thus the base system
> it took to run it was at least $60K (in 1975 dollars) and typically cost
> about two to four times that in practice. Remember the cost of
> acquisition of the HW dominated many (most) choices.
>
> *I**'ll take a guess, but it is only that.* I *suspect* he saw the S-100
> system as closer to a PDP-11/20 'lab' system than as a small
> timesharing machine. He set out with CP/M to duplication the functionality
> from RT/11. He even the naming of the commands was the same as what DEC
> used (*e.g.* PIP) and used the basic DEC style command syntax and parsing
> rules.
That is about it. CP/M predates the Altair / S-100 bus, and was designed for a heavily hacked Intellec-8 system.
CP/M was developed on a PDP-10 based 8080 simulator in 1974. It was developed for the dual purposes of creating a “native” PL/M compiler and to create the “astrology machine”.
The first versions of CP/M were written (mostly) in PL/M. To some extent, in 1974 both Unix and CP/M were research systems, with a kernel coded in a portable language — but aimed at very different levels of hardware capability.
In 1975 customers started to show up and paid serious money for CP/M (Omron, IMSAI) - from that point on the course for Kildall / DRI was set.
The story is here: https://computerhistory.org/blog/in-his-own-words-gary-kildall/?key=in-his-own-words-gary-kildall <https://computerhistory.org/blog/in-his-own-words-gary-kildall/?key=in-his-own-words-gary-kildall>
[-- Attachment #2: Type: text/html, Size: 3607 bytes --]
next reply other threads:[~2021-04-10 18:13 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-10 18:12 Paul Ruizendaal via TUHS [this message]
-- strict thread matches above, loose matches on Subject: below --
2021-04-07 0:59 Jason Stevens
2021-04-06 15:35 M Douglas McIlroy
2021-04-06 17:09 ` Clem Cole
2021-04-06 17:32 ` Charles H Sauer
2021-04-06 20:11 ` Josh Good
2021-04-06 20:26 ` Jim Capp
2021-04-06 20:47 ` Charles H Sauer
2021-04-07 16:42 ` Josh Good
2021-04-07 18:04 ` Charles H. Sauer
2021-04-07 2:49 ` Dave Horsfall
2021-04-07 6:04 ` arnold
2021-04-07 16:01 ` heinz
2021-04-06 21:06 ` Clem Cole
2021-04-07 0:58 ` heinz
2021-04-07 1:37 ` Warner Losh
2021-04-07 3:38 ` Dave Horsfall
2021-04-07 2:30 ` Ed Bradford
2021-04-07 2:44 ` Charles H. Sauer
2021-04-06 20:20 ` Boyd Lynn Gerber
2021-04-06 22:41 ` Dave Horsfall
2021-04-07 1:10 ` Jon Steinhart
2021-04-07 1:47 ` Greg 'groggy' Lehey
2021-04-07 1:49 ` Jon Steinhart
2021-04-07 1:58 ` Larry McVoy
2021-04-07 2:31 ` Serge Burjak
2021-04-09 21:24 ` Michael Parson
2021-04-10 3:33 ` Ed Bradford
2021-04-10 15:12 ` Clem Cole
2021-04-10 15:41 ` Larry McVoy
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=C0701400-5508-48B6-927E-C3B2E8658588@planet.nl \
--to=tuhs@minnie.tuhs.org \
--cc=pnr@planet.nl \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).