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: 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 ---------------------------------------------------------------------------------------------- Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/
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