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From: floyd@hayes.ims.alaska.edu (Floyd Davidson)
Newsgroups: comp.arch
Subject: Re: Zilog's mnemonics; a boon to programmers
Message-ID: <1990Nov16.050844.12539@hayes.ims.alaska.edu>
Date: 16 Nov 90 05:08:44 GMT
References: <1990Nov4.014901.23819@zoo.toronto.edu> <3747@skye.ed.ac.uk> <5584@labtam.labtam.oz>
Organization: University of Alaska Fairbanks
Lines: 32

In article <5584@labtam.labtam.oz> graeme@labtam.labtam.oz (Graeme Gill) writes:
>In article <3747@skye.ed.ac.uk>, richard@aiai.ed.ac.uk (Richard Tobin) writes:
>> In article <1768@metaphor.Metaphor.COM> djh@neuromancer.metaphor.com (Dallas J. Hodgson) writes:
>> >Ahem, excuse me, but Zilog's mnemonics were readable and orthogonal in a way
>> >that Intel's never were
>> 
>> Quite true.  The problem was that the orthogonality of the mnemonics
>> led one to write instructions that didn't in fact exist.
>> 
>
>	and this took a little while to learn, but was made easier thanks to
>some really useful charts showing the legal combinations of mnemonics
>and registers, together with the op codes in the Zilog data book. Made had
>assembly pretty easy too.

It is also true that some of those instructions that don't exist (in
the books, anyway) do some strange things, some of which were very
useful.  It has been too long for me to remember exactly what they
are, but I think 8 bit manipulation of the index registers were the
useful ones.

( And who actually found Intel mnemonics better than Zilog?? Yucckkkkk)

Floyd




-- 
Floyd L. Davidson   floyd@hayes.ims.alaska.edu    floydd@chinet.chi.il.us
Salcha, AK 99714    connected by paycheck to Alascom, Inc.
When *I* speak for them, one of us will be *out* of business in a hurry.