Re: [stella] The mother of all bankswitching trickery :-)

Subject: Re: [stella] The mother of all bankswitching trickery :-)
From: Manuel Polik <cybergoth@xxxxxxxx>
Date: Sat, 07 Dec 2002 18:11:35 +0100
Hi Paul!

>Cool.  So I guess they just modify the JMP address each 
time to call 
>different subroutines in the upper bank?  How do they 
get back?  Same way?

I Have to analyze that further...

> It's clever, but I sure can't see wasting 6 bytes of 
> RAM for bankswitching!

It's strange, yes. I thought it was probably to prevent 
reverse-engineering?

I found yet another oddity speaking for that theory:

The second bank starts like this:

; Second bank

       ORG $2000
       RORG $F000

START2:
       LDA    $FFF8   ;4
       JMP    $BC96   ;3

See? That jump is heading towards nirvana!

And I think *just* tweaking the pointer wouldn't even 
save any ROM in exchange for sacrificing them 6 bytes of 
RAM...

Greetings,
	Manuel

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