Hello,
I've been on this list for years, but I'm just beginning to mess with
some 2600 code this week. I was inspired by Joe Decuir's great
discussion of the Combat code at CGExpo, plus watching the
Glenn's Volume 1 video :)
So far I've got a scrolling background and some playfield going, to
get my feet wet.
I'm now trying to write some code which will detect whether or not
the supercharger is running in regular or modified mode. I hadn't
seen code that does this but I thought it might be handy for testing
the modification.
At any rate, does this sound like a good methodology...?:
1) load the code into F000-FFFF from the supercharger
(assume you are using bank 3 for F000-F7FF, and that the
there is nothing but the start vector in F800-FFFF)
2) switch to bank 3,1 mode, enabling RAM writing
3) write a #$55 to F800
4) switch to bank 3,2 mode, enabling RAM writing
5) write a #$aa to F800
6) Switch to bank 3,1 mode, read F800, compare to #$55...
7) Switch to bank 3,2 mode, read F800, compare to #$aa...
8) If 6&7 pass, then bank switching is working and the
supercharger is umodified...else it is modified
Also, are there any timing things to watch out for regarding bank
switching or ram access? I've been looking at Chris Salomon's
doc, but i'm wondering if there is any code that does this kind of
thing already...since it's not quite working
Thanks,
Frank
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