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From: norman@nose.cs.utoronto.ca (Norman Wilson)
Subject: [TUHS] 6-bit, 7-bit and 9-bit byte UNIXes
Date: Thu, 30 Sep 2004 20:47:22 -0400	[thread overview]
Message-ID: <20041001005644.2B3F7373@minnie.tuhs.org> (raw)

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


             reply	other threads:[~2004-10-01  0:47 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-10-01  0:47 Norman Wilson [this message]
2004-10-01  1:05 ` Andru Luvisi
  -- strict thread matches above, loose matches on Subject: below --
2004-10-01  3:59 Carl Lowenstein
2004-09-30 23:46 James Petts
2004-09-30 19:07 Natalia Portillo
2004-09-30 23:57 ` Greg 'groggy' Lehey
2004-10-01  0:21 ` Kenneth Stailey
2004-10-01  0:58 ` Michael Davidson

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