Re: [stella] 6502 question (was INV+ ... )

Subject: Re: [stella] 6502 question (was INV+ ... )
From: "Kroko" <Nil.Krokodil@xxxxxxx>
Date: Wed, 7 Apr 2004 00:43:44 +0200
> But it would help if anyone knows this.  Does anyone have a 6502 
> reference as to exactly what JSR does on a cycle-by-cycle basis?

I think is like this:


        #  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

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