A question regarding illegal Opcodes.

From: Apu Kuntur (apu.kuntur_at_t-online.de)
Date: 05/23/04 

Date: Sun, 23 May 2004 19:03:13 +0200

Well, its quite a long time ago, when the 6502 Processor was quite new.
I learned coding in Assembly Machine Code in these times and was quickly
realizing that the illegal Opcodes were sometimes quite a good tool for
quicker and sometimes more efficient coding or crack-proofing the program.

Since some months I am back programing with MASM and (yes!) HLA. During
my recherches in diverse Manuals (Intel and AMD) and some Internetpages
I found only one page which includes illegal Opcodes for the Intel
80386, but it is dating back to 1995 and obviously is not regularly
maintained.

Now to my question: Are there any experiences with undocumented Opcodes
for the more recent processors? Okay, they are not really necessary
anymore, but I am interested in these things.

Any ideas and valuable (!) comments are appreciated,

yours,

SNK.

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