Date   : Sat, 04 Jul 1992 05:12:24 GMT
From   : daffodil!wyvern!alpha@ames.arc.nasa.gov (Joe Wright)
Subject: Re: undocumented Z80 Ops

weberj@dia.informatik.uni-stuttgart.de (Weber) writes:
: Are there further undocumented Z80 Codes besides those
: that address IX/IY as 8 Bit registers?
: 
: I have also tested SLIA (shift left inverted arithmetic) and 
: TSTI (C) (set flags corresponding to port (C) ).
: 
There are quite a few of them.  If you have more time than you
really know what to do with, draw a 'map' (actually several maps)
of the z80 opcodes by class.  Fill it in with the 'documented'
operations and then have a hard look at the blanks.  This is
where the 'undocumented' codes live.  Their relation to the others
give a clue of what they might do.

-- 
Joe Wright  alpha@wyvern.twuug.com