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Path: utzoo!linus!security!genrad!grkermit!masscomp!clyde!floyd!harpo!seismo!hao!hplabs!hpda!fortune!norskog
From: norskog@fortune.UUCP
Newsgroups: net.flame
Subject: Re: Godless 68000 instruction set - (nf)
Message-ID: <1979@fortune.UUCP>
Date: Wed, 14-Dec-83 23:02:50 EST
Article-I.D.: fortune.1979
Posted: Wed Dec 14 23:02:50 1983
Date-Received: Sat, 17-Dec-83 01:25:38 EST
Sender: notes@fortune.UUCP
Organization: Fortune Systems, Redwood City, CA
Lines: 29

#R:hp-dcde:32700001:fortune:3400020:000:762
fortune!norskog    Dec 14 17:34:00 1983

You want the stack pointer to always be word-aligned so that interrupts
don't cause a cascade of bus faults.  Disallowing odd-address
non-byte accesses was real dumb.

More flames:
They set up everything for a nice virtual memory machine,
except that they forgot about instruction restarts.
And another one: the timing for bus-faults is just slightly 
too tight to implement error-correcting RAM.

Do 68020 (32-bit data bus) accesses have to be quad-aligned? Just
word-aligned? Or does it allow odd-aligned word & longword accesses?
If it's quad-aligned only then they might as well trash it.
No 68K software would work.


				Lance Norskog
				Fortune Systems
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