^X (was: an odd question

From: Mark Green <mark_at_cs.ualberta.ca>
Date: Fri Aug 10 12:39:47 2001

> On Thu, Aug 09, 2001 at 08:13:20PM -0600, Mark Green wrote:
> > The CDC Cyber series had many different character sets, which was a
> > major pain in the ass for anyone maintaining software for them. I
> > spent several years working on the Pascal compiler for the CDC
> > machines (the orignal implementation from ETH).
>
> Ah, back at the U of Minn, we used CDC mainframes for our programming
> classes. I tried using as much lower case as the Pascal books did,
> and that did not make things happy.

If I remember correctly the compiler was never modified to
handle lower case letters, but I think the run-time support
could handle them. I worked on the run-time part of the
system, and I recall dealing with the various characters sets.
I also put in the ability to call PPU programs from Pacal
programs. This could also be done directly in Pascal, but
required a fair amount of knowldege and several compiler
cheats, so it wasn't recommended (which is why I did it that
way most of the time). The CDC machines were the first ones
that I used that had real parallelism, learned a hell of a
lot the hard way!

>
>
> -kb, the Kent who also once opened a comment before column 76 and
> didn't close another comment before column 76 for many lines, causing
> the intervening lines to be silently dropped.
>
>
> P.S. Circa 1980 we even did one assignment on a punch card machine.
> The physical reader was a relatively svelt machine (at least compared
> to the central beasts we students could not touch), and it talked to
> an impressive looking, floppy-equipped PDP-11/34, bootstrapped via the
> front panel and everything. (Did they call the whole thing a Remote
> Job Entry Station?) What *was* that record separator card? A 6-7-8
> overpunch? What was the job separator card??
>

The 6-7-8 was an end or record, and 6-7-8-9 was and end of information.
I seem to recall that on some devices (tape and cards??) two end of
records in a row generated an end of information.

A number of mini's were used as batch input systems on the CDC's.
It was fairly easy to produce software for this, the protocol was
available from CDC. We produced a version that would run on an
HP2100, so something as modern as an 11/34 would have no problem
with it.

One of the interesting things about the CDC machines, is that the PPU
programs didn't change from one version of the operation system to
another. I can still recall looking at PPU program listings that
had the following comment at the start:

Translated to assembler from the original binary entered by
Seymour Cray.

I heard a story that the first operating system for the 6000 series
machines was written in several weeks in Seymour Cray's cottage
by a small group of programmers.
Received on Fri Aug 10 2001 - 12:39:47 BST