Sujet : Re: PDP-6/10 text, Byte Addressability And Beyond
De : johnl (at) *nospam* taugh.com (John Levine)
Groupes : comp.archDate : 01. May 2024, 20:37:07
Autres entêtes
Organisation : Taughannock Networks
Message-ID : <v0u24j$20eg$1@gal.iecc.com>
References : 1 2 3 4
User-Agent : trn 4.0-test77 (Sep 1, 2010)
Thomas Koenig wrote:
Hmm... what sort of terminals and character sets did people use on
a PDP-10? 7-bit ASCII? It (and the PDP-6) were released before
the ASCII standard came out.
On the PDP-6 and PDP-10s I used they were all Teletypes and tty
compatible ASCII video terminals.
The normal way to store text was five 7-bit ASCII characters in a 36
bit word, since the byte handling instructiond made that easy to
handle. It was common to start each line on a word boundary, so you had
to skip zero padding bytes. Text editors often included line numbers
that were five digit characters aligned on a word boundary, followed
by a tab. The low bit in the word with the digits was set to say it's
a line number, and compilers knew to look for the bit and skip the
line number and tab.
Disk and DECtape used a six bit upper case ASCII subset for file names
so they could fit a six character name into one word. Compiler and
object file symbol tables used RADIX50 aka SQUOZE that fit a six
character symbol from a 40 character (octal 50) set into 32 bits with
four flag bits left.
(And /360 was supposed to support
ASCII originally, but that bit in the PSW got dropped for the /370,
I believe).
They used a mutant ASCII that expanded from 7 to 8 bits by copying the
high bit into the middle of the byte, which nobody ever used. It was
one of the few inexplicably stupid choices in the 360.
According to MitchAlsup1 <
mitchalsup@aol.com>:
PDP 10 had a 6-bit "field data" character set and a 9-bit bigger than
ASCII character set.
Dunno what computer that was, but it wasn't a PDP-10. Univac or GE600 maybe?
-- Regards,John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",Please consider the environment before reading this e-mail. https://jl.ly
Date | Sujet | # | | Auteur |
1 May 24 | Byte Addressability And Beyond | 590 | | Lawrence D'Oliveiro |
1 May 24 | Re: Byte Addressability And Beyond | 431 | | John Levine |
1 May 24 | Re: Byte Addressability And Beyond | 409 | | Lawrence D'Oliveiro |
1 May 24 | Re: Byte Addressability And Beyond | 3 | | John Levine |
1 May 24 | Re: Byte Addressability And Beyond | 1 | | John Levine |
1 May 24 | Re: Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
1 May 24 | Re: Byte Addressability And Beyond | 1 | | Michael S |
1 May 24 | Re: Byte Addressability And Beyond | 404 | | John Levine |
2 May 24 | Re: Byte Addressability And Beyond | 382 | | Lawrence D'Oliveiro |
2 May 24 | Re: Byte Addressability And Beyond | 4 | | John Levine |
2 May 24 | Re: Byte Addressability And Beyond | 3 | | Lawrence D'Oliveiro |
2 May 24 | Re: Byte Addressability And Beyond | 2 | | John Levine |
5 May 24 | Re: Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
2 May 24 | Re: Byte Addressability And Beyond | 367 | | John Savard |
2 May 24 | Re: Byte Addressability And Beyond | 2 | | MitchAlsup1 |
11 May 24 | Re: Byte Addressability And Beyond | 1 | | John Savard |
4 May 24 | Re: Byte Addressability And Beyond | 364 | | Lawrence D'Oliveiro |
8 May 24 | Re: Byte Addressability And Beyond | 363 | | John Savard |
8 May 24 | Re: Byte Addressability And Beyond | 2 | | Lawrence D'Oliveiro |
10 May 24 | Re: Byte Addressability And Beyond | 1 | | David Brown |
8 May 24 | Re: Byte Addressability And Beyond | 360 | | MitchAlsup1 |
8 May 24 | Re: Byte Addressability And Beyond | 359 | | John Levine |
8 May 24 | Re: Byte Addressability And Beyond | 357 | | Lawrence D'Oliveiro |
9 May 24 | Re: Byte Addressability And Beyond | 356 | | John Levine |
10 May 24 | Re: Byte Addressability And Beyond | 354 | | David Brown |
10 May 24 | Re: Byte Addressability And Beyond | 353 | | Anton Ertl |
11 May 24 | Re: Byte Addressability And Beyond | 352 | | David Brown |
11 May 24 | Re: Byte Addressability And Beyond | 351 | | Anton Ertl |
11 May 24 | Re: Byte Addressability And Beyond | 158 | | David Brown |
11 May 24 | Re: Byte Addressability And Beyond | 1 | | Anton Ertl |
27 May 24 | Re: Byte Addressability And Beyond | 156 | | Lawrence D'Oliveiro |
27 May 24 | Re: Byte Addressability And Beyond | 155 | | John Levine |
27 May 24 | Re: Byte Addressability And Beyond | 154 | | Lawrence D'Oliveiro |
27 May 24 | Re: Byte Addressability And Beyond | 153 | | John Levine |
27 May 24 | Re: Byte Addressability And Beyond | 149 | | John Levine |
27 May 24 | Re: Byte Addressability And Beyond | 1 | | MitchAlsup1 |
28 May 24 | Re: Byte Addressability And Beyond | 147 | | Lawrence D'Oliveiro |
28 May 24 | Re: encoding conversion, Byte Addressability And Beyond | 1 | | John Levine |
28 May 24 | Re: Byte Addressability And Beyond | 145 | | Thomas Koenig |
29 May 24 | Re: Byte Addressability And Beyond | 137 | | Lawrence D'Oliveiro |
29 May 24 | Re: Byte Addressability And Beyond | 136 | | Anton Ertl |
29 May 24 | Re: Byte Addressability And Beyond | 12 | | Stefan Monnier |
29 May 24 | Re: Byte Addressability And Beyond | 10 | | Stefan Monnier |
29 May 24 | Re: Byte Addressability And Beyond | 3 | | John Levine |
30 May 24 | Re: Byte Addressability And Beyond | 2 | | George Neuner |
4 Jun 24 | Re: Byte Addressability And Beyond | 1 | | George Neuner |
30 May 24 | Re: Byte Addressability And Beyond | 6 | | Anton Ertl |
4 Jun 24 | Re: Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
4 Jun 24 | Re: Byte Addressability And Beyond | 4 | | Stefan Monnier |
7 Jun 24 | Re: Byte Addressability And Beyond | 1 | | Terje Mathisen |
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30 May 24 | Re: Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
30 May 24 | Re: Byte Addressability And Beyond | 117 | | Lawrence D'Oliveiro |
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30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 22 | | Anton Ertl |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 21 | | Thomas Koenig |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 8 | | Michael S |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Thomas Koenig |
30 May 24 | Re: IBM architectural goals, Byte Addressability And Beyond | 5 | | John Levine |
30 May 24 | Re: IBM architectural goals, Byte Addressability And Beyond | 2 | | Michael S |
30 May 24 | Re: IBM architectural goals, Byte Addressability And Beyond | 1 | | John Levine |
30 May 24 | Re: IBM architectural goals, Byte Addressability And Beyond | 2 | | Thomas Koenig |
30 May 24 | Re: IBM architectural goals, Byte Addressability And Beyond | 1 | | John Levine |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Anton Ertl |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 3 | | Anton Ertl |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | John Levine |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Thomas Koenig |
31 May 24 | Re: architectural goals, Byte Addressability And Beyond | 5 | | Terje Mathisen |
1 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 4 | | Thomas Koenig |
1 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 3 | | Anton Ertl |
2 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 2 | | John Levine |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Stefan Monnier |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 4 | | Lawrence D'Oliveiro |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | MitchAlsup1 |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Lynn Wheeler |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Stefan Monnier |
31 May 24 | Re: architectural goals, Byte Addressability And Beyond | 42 | | John Savard |
31 May 24 | Re: architectural goals, Byte Addressability And Beyond | 41 | | John Levine |
1 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 31 | | John Savard |
1 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 20 | | Thomas Koenig |
2 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 6 | | John Savard |
2 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 5 | | Thomas Koenig |
2 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 3 | | John Levine |
3 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 2 | | OrangeFish |
3 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | John Levine |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 13 | | Lawrence D'Oliveiro |
5 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 12 | | Lawrence D'Oliveiro |
5 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
6 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 10 | | George Neuner |
6 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 6 | | John Levine |
7 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 4 | | Lawrence D'Oliveiro |
7 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 3 | | Stephen Fuld |
7 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 2 | | Lawrence D'Oliveiro |
7 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Stephen Fuld |
7 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Terje Mathisen |
6 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Lynn Wheeler |
6 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | OrangeFish |
7 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
2 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 10 | | John Dallman |
2 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Michael S |
2 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | John Dallman |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 7 | | Lawrence D'Oliveiro |
30 May 24 | Re: Byte Addressability And Beyond | 49 | | Stephen Fuld |
30 May 24 | Re: Byte Addressability And Beyond | 1 | | Anton Ertl |
30 May 24 | Re: Byte Addressability And Beyond | 2 | | Lawrence D'Oliveiro |
30 May 24 | Re: Byte Addressability And Beyond | 4 | | Terje Mathisen |
30 May 24 | Re: Byte Addressability And Beyond | 7 | | Terje Mathisen |
28 May 24 | Re: Byte Addressability And Beyond | 3 | | Lawrence D'Oliveiro |
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8 May 24 | Re: Byte Addressability And Beyond | 1 | | Michael S |
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1 May 24 | Re: Byte Addressability And Beyond | 15 | | Thomas Koenig |
1 May 24 | Re: Byte Addressability And Beyond | 3 | | Michael S |
2 May 24 | Re: Byte Addressability And Beyond | 4 | | Lawrence D'Oliveiro |
3 May 24 | Re: Byte Addressability And Beyond | 75 | | Anton Ertl |
5 May 24 | Re: Byte Addressability And Beyond | 20 | | John Savard |
5 May 24 | Re: Byte Addressability And Beyond | 1 | | John Savard |