Re: [stella] FE bank switching again

Subject: Re: [stella] FE bank switching again
From: Adam Wozniak <adam@xxxxxxxxxxxxxxxx>
Date: Fri, 24 Jan 2003 10:15:34 -0800 (PST)
Ahhh.. Thanks.  That's what I was looking for...

On Thu, 23 Jan 2003, Eric Ball wrote:

> The following (from http://www-2.cs.cmu.edu/~dsladic/vice/doc/64doc.txt) may
> help you figure out how FE works:
> 
>      RTS
> 
>         #  address R/W description
>        --- ------- --- -----------------------------------------------
>         1    PC     R  fetch opcode, increment PC
>         2    PC     R  read next instruction byte (and throw it away)
>         3  $0100,S  R  increment S
>         4  $0100,S  R  pull PCL from stack, increment S
>         5  $0100,S  R  pull PCH from stack
>         6    PC     R  increment PC
> 
>      JSR
> 
>         #  address R/W description
>        --- ------- --- -------------------------------------------------
>         1    PC     R  fetch opcode, increment PC
>         2    PC     R  fetch low address byte, increment PC
>         3  $0100,S  R  internal operation (predecrement S?)
>         4  $0100,S  W  push PCH on stack, decrement S
>         5  $0100,S  W  push PCL on stack, decrement S
>         6    PC     R  copy low address byte to PCL, fetch high address byte
> to PCH

-- 
Will code for food.       http://cuddlepuddle.org/~adam/resume.html

adam@xxxxxxxxxxxxxxxx        http://cuddlepuddle.org/~adam/pgp.html

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