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From: sealbrec@acs.ucalgary.ca (Alvin Albrecht)
Newsgroups: comp.sys.sinclair
Subject: Re: EX DE,HL => EX DE,IX ?
Date: 12 May 1996 14:28:55 -0600
Organization: The University of Calgary
Lines: 19
Message-ID: <4n5hm7$sjq@acs5.acs.ucalgary.ca>
References: <31933C58.19C3@cs.bham.ac.uk> <4mvjl6$5bb@relay.lsl.co.uk> <1996May11.132646.517@pat.uwe.ac.uk>
NNTP-Posting-Host: sealbrec@acs5.acs.ucalgary.ca

In article <1996May11.132646.517@pat.uwe.ac.uk>,
R Ribeiro <rff-ribe@uwe.ac.uk> wrote:

>	I also came across this doubt and tested it on the past. It worked
>in my Z80. But, let's not forget that not all Z80s accepted all the
>undocumented instructions. If I am not wrong, they were undocumented because
>the first Z80s coming out had a problem on their manufucture that prevented
>them to work. Have I dreamed all this? The people who still have their
>trustuffull Z80 at home can help clarify this?

I tested it on my Z80 too and found that it performed an EX DE,HL and
not an EX DE,IX.

I also seem to remember reading about the undocumented opcodes.  Apparently,
they were located on the outside edges of the die and were thus unreliable.


Alvin