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From: davidsen@steinmetz.ge.com (William E. Davidsen Jr)
Newsgroups: comp.arch,comp.sys.intel
Subject: Re: i860 overview (long)
Message-ID: <13352@steinmetz.ge.com>
Date: 13 Mar 89 17:00:35 GMT
References: <807@microsoft.UUCP> <92634@sun.uucp> <13322@steinmetz.ge.com> <340@wjh12.harvard.edu>
Reply-To: davidsen@crdos1.UUCP (bill davidsen)
Organization: General Electric CRD, Schenectady, NY
Lines: 34

In article <340@wjh12.harvard.edu> bb@wjh12.UUCP (Brent Byer) writes:
| In article <13322@steinmetz.ge.com> davidsen@crdos1.UUCP (bill davidsen) writes:
| > .... One of the people here checked his Sun-30
| >(68020) against his Sun-4 (SPARC). The three ran troff about 5x faster.
| >
| One of the signs of competency in a good engineer is that, while (s)he
| might not always know the right answer, (s)he should always be able
| to detect an obviously wrong one.  Bill Davidsen has presented data
| which is bogus by at least a factor of 10; a question, Bill:
| 	Don't you think you should have verified this data *before*
| 	trying to use it to support your claims?

  As far as I know the only claim I made was that the results were
reported to me as I stated, leading to an interest in the ability to
access byte. Someone pointed out that byte address and byte access
aren't quite the same thing, thanks.

  I mentioned the case in which a byte is extracted by doing a word load
and isolating a byte in the word. Ten people told me no one does that
any more, four people said "yes the 29000 does just that. At this point
I really don't care. I mentioned the Honeywell 6000, someone immediately
pointed out the EIS instruction set. By adding a coprocessor I can make
any CPU have any instructions, but I'm not sure that justifies claiming
something as a feature.

  As far as floating point in troff, I timed it on a VAX with and
without FPU and it sure runs faster with. One person claimed that the
FPU makes integer divide faster, and two others said it improves context
switching. I checked four troff sources, and BSD/V7 troff don't have
f.p., one vendor supplied version does.
-- 
	bill davidsen		(wedu@ge-crd.arpa)
  {uunet | philabs}!steinmetz!crdos1!davidsen
"Stupidity, like virtue, is its own reward" -me