Z80 Divide by 10

Jim Leonard trixter at oldskool.org
Mon Jan 28 17:35:46 CST 2008


Fred Cisin wrote:
>>> Can we just shoot the designers of the 8086 and just leave it that. !?
> 
> On Mon, 28 Jan 2008, Jim Leonard wrote:
>> But seriously -- why?  I didn't find it all that horrible -- in fact, I
>> missed the string handling (REP MOVSW/STOSW/SCASW/etc.) on all the other
>> platforms I mentioned.  If they truly deserve to be shot, I want to know
>> why :-)
> 
> Some people get rather upset at the lack of symmetry, and lack of certain
> instructions that might be handy, such as a load immediate into segment
> registers.

Hm... Yeah, I guess that was a hassle.  808x you have to:

MOV AX,immed
MOV ES,AX

or

PUSH DS
POP ES

...etc.  Still, two instructions vs. one isn't that big a deal; I got 
used to it.

I guess the one annoying thing with 808x is that, 80286 and later, they 
removed POP CS.  So if you used that for tricks, it immediately dies on 
anything other than an 808x.
-- 
Jim Leonard (trixter at oldskool.org)            http://www.oldskool.org/
Help our electronic games project:           http://www.mobygames.com/
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A child borne of the home computer wars: http://trixter.wordpress.com/



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