RE: [stella] RIOT RAM test

Subject: RE: [stella] RIOT RAM test
From: Manuel Polik <cybergoth@xxxxxxxx>
Date: Sat, 30 Nov 2002 14:39:49 +0100
Hi Glenn!

>If you attempt to "fry" the 2600 (6 switcher or 4 
swithcer) then we can see 
>if the RAM contents come through completely random or 
if there is a fixed 
>number of possible patterns.
>I suspect the latter, otherwise Frying effects would 
not be as easy to 
>generate on games like Space Invaders.
>It would be nice to catalog which bytes of RAM frying 
alters and to which 
>values to create different effects in particular games.  
Then we can 
>understand why these values have these effects (like 
the double missiles in 
>Space Invaders).

I don't think frying effects depend on RAM contents. 
I've never dissassembled Space Invaders, but I've never 
seen any classic game at all that doesn't completely 
clear the zeropage on startup.

If you'd ask me, I'd say that the only possibillity for 
the frying effect would be a misreading of the FFFC/D 
vector on start-up and/or missetting the PC on the 
booting-sequence of the VCS.


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