[Simh] 6-bit variants of ASCII (AKA DEC SIXBIT)

[Shoppa, Tim]

Looking at references that Al and others have already mentioned

(and I'd like to add: http://www.transbay.net/~enf/ascii/ascii.pdf which also mentions EBCDIC and ECMA-1)

(and also add the PDP-1 documentation on "Concise code" and "FIO-DEC" codes which seem to be related to a specific model of Flexowriter... I'm not sure which came first, the FIO-DEC code or the Flexowriter FIO)

I'm astonished at the flurry of standards activities in character codes in the 1960-1963 timeframe. That doesn't mean that six bit codes didn't exist earlier, just that the flurry of standards activities is astonishing.

I think sometimes it is very common for Wikipedia authors to mistake standards committee activities as being the only activities. Wikipedia's policies encouraging (requiring?) references to standards documents make it very easy to go down this road but it can be misleading. There are things adopted in standards committees that are never implemented in real life. And there's lots of things implemented in real life that are never part of a standard.

-----Original Message-----
From: simh-bounces at trailing-edge.com [mailto:simh-bounces at trailing-edge.com] On Behalf Of Sergii Kolisnyk
Sent: Monday, May 10, 2010 10:03 AM
To: simh at trailing-edge.com
Subject: [Simh] 6-bit variants of ASCII (AKA DEC SIXBIT)

Hello!

Could you give me some web links to definitive manuals on DEC SIXBIT codes?
If there are none, may be somebody could take time and tell from his memories
about _different_variants_ ?

I'm putting what I can find or remember here:
http://en.wikipedia.org/wiki/Sixbit_code_pages
I have found ECMA-1 standard (may be you know its ANSI and/or ISO names?)
http://www.ecma-international.org/publications/files/ECMA-ST-WITHDRAWN/ECMA-1,%201st%20Edition,%20March%201963.pdf

ECMA-5 tells to use DEL-escaping to represent full ASCII code space:
http://www.ecma-international.org/publications/files/ECMA-ST-WITHDRAWN/ECMA-5,%203rd%20Edition,%20June%201970.pdf

I'm also wondering how it got into ISO/IEC 7811-2
http://cardforum.cardprom.ru/standard/ISO-card-magnetic18.gif

Could you correct my mistakes, if any?
(As I remember, PDP-8 used other variant, with halves of code space
swapped, so A got 01 code.)

Thank you in advance!

Best regards,
Sergii Kolisnyk
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