AW: [stella] "Illegal" opcodes

Subject: AW: [stella] "Illegal" opcodes
From: "Jentzsch, Thomas" <TJentzsch@xxxxxxxxxxxx>
Date: Mon, 19 Jun 2000 11:47:05 +0200
>Why don't we test this out?

>We should create a test program that uses most of the undocumented 
>instructions, then test it on as many 2600 variants as possible.

That's a good idea. There are not many usefull illegal opcodes, 
i've only used LAX(lda/ldx), DCP(dec,cmp) and NOOP(2/3 bytes NOPs)
in many years C64 programming. Most of the other opcodes operate 
very weird, others seem to work different even on the same platform
and sometimes different mnemonics are used. 
So we have to look at different sources to verify their informations.
I've found this page:

So let's first figure out, which opcodes should be tested.


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