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From: crowl@cs.rochester.edu (Lawrence Crowl)
Newsgroups: comp.lang.c,comp.arch
Subject: Bit Addressable Architectures
Message-ID: <7374@sol.ARPA>
Date: 4 Mar 88 17:26:51 GMT
References: <11702@brl-adm.ARPA> <243@eagle_snax.UUCP> <2245@geac.UUCP> <1988Mar3.182645.703@utzoo.uucp>
Reply-To: crowl@cs.rochester.edu (Lawrence Crowl)
Organization: U of Rochester, CS Dept, Rochester, NY
Lines: 20

In article <1988Mar3.182645.703@utzoo.uucp> henry@utzoo.uucp
(Henry Spencer) writes:
>I once had the opportunity to ask Bill Wulf what he thought of bit-oriented
>machines; his answer was "I wish they weren't so damned slow".  I'm afraid
>I haven't seen anything since that invalidates that assessment.  There is
>something to be said for providing bit addressability, but one must realize
>that actually exploiting it will be slow and that there will still be a
>large payoff for trying to work on byte or word boundaries whenever possible.

It seems to me that aligned access to all items larger than a bit would allow
a bit addressable machine to be every bit as fast as a byte or word addressable
machine.  Am I missing something?

A bit addressable machine would allow us to use single bits, nibbles, BCD, etc.
with much greater ease.  Besides, bit addressability seems "right".  (I know,
"right" isn't a rational statement!)
-- 
  Lawrence Crowl		716-275-9499	University of Rochester
		      crowl@cs.rochester.edu	Computer Science Department
...!{allegra,decvax,rutgers}!rochester!crowl	Rochester, New York,  14627