Path: utzoo!attcan!uunet!husc6!bloom-beacon!gatech!mcnc!uvaarpa!babbage!mac3n
From: mac3n@babbage.acc.virginia.edu (Alex Colvin)
Newsgroups: comp.arch
Subject: Re: unsigned / addresses
Summary: unsigned for bignum
Message-ID: <310@babbage.acc.virginia.edu>
Date: 17 May 88 13:15:55 GMT
References: <11571@ut-sally.UUCP> <28200145@urbsdc> <11618@ut-sally.UUCP>
Organization: University of Virginia
Lines: 17

> > >massage them, since there are no negative photons (unlike negative addresses).
> > What do you care if you are counting in a signed integer, and just
> > use half the range?
> 
> Unfortunatly I have found no simple way to get the star to cooperate with
> respect to counting rates.  Sometimes 16 bits are enough, sometimes 32

That does bring up a point.  What's needed there is big numbers.  Unsigned
arithmetic lets you get one more bit, doubling your range.

After that, you go to multi-word (multi-accumulator-width) counters.
Pronounced "bignum", with a lisp.  In the usual case, the sign appears only
in the MSW and applies to all.  I expect that unsigned arithmetic makes
this easier, but I'm not sure.  Does it?

In any event, no machine that I know of (well, maybe an old Honeywell) does
multiword addressing.