Re: [stella] 2600 bankswitched games on 7800 RAM cart

Subject: Re: [stella] 2600 bankswitched games on 7800 RAM cart
From: "Eckhard Stolberg" <Eckhard_Stolberg@xxxxxx>
Date: Sat, 19 Apr 2003 20:13:38 +0200
> It seems like you should be able to write a preprocessor that reads in
> a binary for a bankswitched 2600 game and produces a new binary which
> will run on a 7800 ram cart.
>
> For some bank switching schemes (FE) this preprocessor would be incredibly
> simple.
>
> Thoughts?

The 7800CTRL program already has some command line switches to
double the 4K banks for 2600 games in normal or reversed order.
For FE bankswitched games that should already do the trick. For
other bankswitching schemes a preprocessor probably can't be
created, because to reliably identify all code pieces that trigger
the bankswitching you'd have to run the game. This is also the
reason why there is no automatic disassembler for VCS games that
are larger than 4K.

You can use the 7800 RAM cart to simulate F8/F6 bankswitching
though, if you compile the banks for different areas of the
7800 memeory map and put in direct jumps to these addresses
instead of instruction for triggering the bankswitching. Some
of the later Atari bankswitched games were written on a similar
setup with Atari's own 7800 dev cart.


Ciao, Eckhard Stolberg


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