[TUHS] 6-bit, 7-bit and 9-bit byte UNIXes

[TUHS] 6-bit, 7-bit and 9-bit byte UNIXes

[James Petts]

Natalia

I don't know of any non-8-bit Unix systems, but Multics, on the GE645 at
least, had a 36-bit word. See

http://en.wikipedia.org/wiki/Multics

James


----- Original Message -----
From: "Natalia Portillo" <iosglpgc@teleline.es>
Date: Thu, 30 Sep 2004 20:07:46 +0100
To: <tuhs at tuhs.org>
Subject: [TUHS] 6-bit, 7-bit and 9-bit byte UNIXes

> Hi!
> 
> Was there any UNIX with 6-bit wide, 7-bit wide or 9-bit wide bytes or all
> UNIXes are 8-bit wide bytes?
> 
> Regards
> 
> _______________________________________________
> TUHS mailing list
> TUHS at minnie.tuhs.org
> http://minnie.tuhs.org/mailman/listinfo/tuhs

[TUHS] 6-bit, 7-bit and 9-bit byte UNIXes

[Carl Lowenstein]

> Subject: Re: [TUHS] 6-bit, 7-bit and 9-bit byte UNIXes
> From: Norman Wilson <norman at nose.cs.utoronto.ca>
> To: tuhs at tuhs.org
> Date: Thu, 30 Sep 2004 20:47:22 -0400
> 
> The very first UNIX ran on the PDP-7, which had 18-bit words.
> 
> I happen to have the assembly-language source code to parts
> of that system.  Many programs contain error-handling code
> that does something like this:
> 
> 	lac d1
> 	sys write; 1f; 1
> 	jmp somewhere
> 
> 1:	077012
> 
> 	...
> 
> d1:	1
> 
> Evidently the system thought in words in those days
> (the second argument to sys write is presumably a word
> count), but the single word written is a strong clue
> that 9-bit bytes were used, and that a certain concise
> error message that people love to complain about was
> there from the beginning (and why not?).

?

I would say "the PDP7 computer was word-addressable".  In this
context, characters seem to have been packed as 9-bit half-words
in a big-endian fashion.  No 'bytes'.

Maybe tomorrow I will be near my DEC literature archives, and see
if I can find some clues about PDP7 instructions that might deal
with half-words.  If it's anything like the PDP8 of similar vintage,
there aren't any.  Late in its life the PDP8 got a BSW "byte swap"
instruction to swap the half-words in the AC register.  6 bits,
of course.

    carl
-- 
    carl lowenstein         marine physical lab     u.c. san diego
                                                 clowenst at ucsd.edu

[TUHS] 6-bit, 7-bit and 9-bit byte UNIXes

[Andru Luvisi]

On Thu, 30 Sep 2004, Norman Wilson wrote:
> The very first UNIX ran on the PDP-7, which had 18-bit words.
>
> I happen to have the assembly-language source code to parts
> of that system.

Have you donated this code to any archives?  If so, which ones?  If not,
please consider doing so!

Andru
-- 
Andru Luvisi

Quote Of The Moment:
  Goto: The apprentice uses it without thinking. 
        The journeyman avoids it without thinking.
        The master uses it thoughtfully.

[TUHS] 6-bit, 7-bit and 9-bit byte UNIXes

[Michael Davidson]

> 
> Was there any UNIX with 6-bit wide, 7-bit wide or 9-bit wide bytes or all
> UNIXes are 8-bit wide bytes?
> 

BBN had a version of UNIX for the C/70 machine which had 10 bit bytes.

This is memorialized in the "IP/TCP Implementation Status" section of the
historic RFC 801 which describes the NCP to TCP transition plan, thus:

APPENDIX D.  IP/TCP Implementation Status

   Please note that the information in this section may become quickly
   dated.  Current information on the status of IP and TCP
   implementations can be obtained from the file
   <INTERNET-NOTEBOOK>TCP-IP-STATUS.TXT on ISIF.

   BBN C70 UNIX

      Date:  18 Nov 1981
      From:  Rob Gurwitz <gurwitz at BBN-RSM>

      The C/70 processor is a BBN-designed system with a native
      instruction set oriented toward executing the C language.  It
      supports UNIX Version 7 and provides for user processes with a
      20-bit address space.  The TCP/IP implementation for the C/70 was
      ported from the BBN VAX TCP/IP, and shares all of its features.

      This version of TCP/IP is running experimentally at BBN, but is
      still under development.  Performance tuning is underway, to make
      it more compatible with the C/70's memory management system.

[ ... ]

[TUHS] 6-bit, 7-bit and 9-bit byte UNIXes

[Norman Wilson]

The very first UNIX ran on the PDP-7, which had 18-bit words.

I happen to have the assembly-language source code to parts
of that system.  Many programs contain error-handling code
that does something like this:

	lac d1
	sys write; 1f; 1
	jmp somewhere

1:	077012

	...

d1:	1

Evidently the system thought in words in those days
(the second argument to sys write is presumably a word
count), but the single word written is a strong clue
that 9-bit bytes were used, and that a certain concise
error message that people love to complain about was
there from the beginning (and why not?).

Norman Wilson
Toronto ON

[TUHS] 6-bit, 7-bit and 9-bit byte UNIXes

[Kenneth Stailey]

--- Natalia Portillo <iosglpgc at teleline.es> wrote:

> Hi!
> 
> Was there any UNIX with 6-bit wide, 7-bit wide or 9-bit wide bytes or all
> UNIXes are 8-bit wide bytes?
> 
> Regards

Does the PDP-10 port of NetBSD use 9-bit bytes?

http://netbsd.org/Ports/pdp10/

[TUHS] 6-bit, 7-bit and 9-bit byte UNIXes

[Greg 'groggy' Lehey]

On Thursday, 30 September 2004 at 20:07:46 +0100, Natalia Portillo wrote:
> Hi!
>
> Was there any UNIX with 6-bit wide, 7-bit wide or 9-bit wide bytes
> or all UNIXes are 8-bit wide bytes?

On page 182 of K&R 1st edition there's a reference to an
implementation of C on the Honeywell 6000, with 9 bit bytes.  There's
no mention of whether it was running UNIX.

Greg
--
Finger grog at lemis.com for PGP public key.
See complete headers for address and phone numbers.
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[TUHS] 6-bit, 7-bit and 9-bit byte UNIXes

[Natalia Portillo]

Hi!

Was there any UNIX with 6-bit wide, 7-bit wide or 9-bit wide bytes or all
UNIXes are 8-bit wide bytes?

Regards