Re: Guidelines for instruction set design?

Walter Banks <walter@bytecraft.com>
Wed, 13 May 2009 09:49:54 -0400

          From comp.compilers
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[11 earlier articles]
Re: Guidelines for instruction set design? gmt@cs.arizona.edu (2009-05-06)
Re: Guidelines for instruction set design? dot@dotat.at (Tony Finch) (2009-05-07)
Re: Guidelines for instruction set design? gneuner2@comcast.net (George Neuner) (2009-05-10)
Re: Guidelines for instruction set design? toby@telegraphics.com.au (toby) (2009-05-10)
Re: Guidelines for instruction set design? anton@mips.complang.tuwien.ac.at (2009-05-12)
Re: Guidelines for instruction set design? gneuner2@comcast.net (George Neuner) (2009-05-12)
Re: Guidelines for instruction set design? walter@bytecraft.com (Walter Banks) (2009-05-13)
Re: Guidelines for instruction set design? DrDiettrich1@aol.com (Hans-Peter Diettrich) (2009-05-13)
Re: Guidelines for instruction set design? cfc@shell01.TheWorld.com (Chris F Clark) (2009-05-18)
Guidelines for instruction set design? ok@cs.otago.ac.nz (Richard O'Keefe) (2009-05-26)
Re: Guidelines for instruction set design? gopi.onthemove@gmail.com (2009-06-03)
| List of all articles for this month |
From: Walter Banks <walter@bytecraft.com>
Newsgroups: comp.compilers
Date: Wed, 13 May 2009 09:49:54 -0400
Organization: Compilers Central
References: 09-05-020 09-05-042 09-05-049 09-05-054
Keywords: architecture, history
Posted-Date: 13 May 2009 10:10:50 EDT

> [Historical note: C was first implemented on the GE 635, a 36 bit word
> addressed machine with a very complex instruction set that could also
> handle 9 bit bytes. -John]


I think the PDP-11 came first however the GE635 went through an neat
character evolution. Most of its early software used 6 bit character 6
to a word and then when case specific characters started to be used
they were allocated 4 nine bit characters to a word.


Regards
--
Walter Banks
Byte Craft Limited
http://www.bytecraft.com
[The 36 bit machines were all follow-ons to the very successful IBM 704X
and 709X series which had 36 bit words and 6 bit characters. By the early
1960s it was clear that 6 bits wasn't enough. GE hard-coded 6 and 9 bit
bytes in the 635 instruction set, DEC allowed arbitrary bytes in the PDP-6
and -10, and I'm not sure what the Univax 110X series did, but we're pretty
far from compiler design now. -John]


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