Re: [stella] "Illegal" opcodes

Subject: Re: [stella] "Illegal" opcodes
From: Glenn Saunders <cybpunks@xxxxxxxxxxxxx>
Date: Mon, 19 Jun 2000 00:56:17 -0700
At 08:38 AM 6/19/2000 +0200, you wrote:
Which, of course, raises the question if these "illegal" instruction, when
used in a 2600 game, will work on all 2600 variants, including clones like
the TV boy, or not. Maybe some of them use CPU by other manufacturers, which
do execute the official instructions correctly, but not all inofficial

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.

I would expect uniformity on the regular 2600's up until the crash, but I'd be interested in knowing, for instance, whether a late era Atari Corp. 2600 Jr. or a 7800 (with its underclocked 6502C) would work correctly.

Glenn Saunders - Producer - Cyberpunks Entertainment Personal homepage: Cyberpunks Entertainment:

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