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cpu indirect addressing modes
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Author:  mattmatteh [ Fri Oct 06, 2006 1:22 pm ]
Post subject:  cpu indirect addressing modes

does the 6502 have an internal register for indirect addressing modes to store the pointer? also, is there an internal register to hold the address for the address bus?

matt

Author:  tepples [ Fri Oct 06, 2006 2:20 pm ]
Post subject:  Re: cpu indirect addressing modes

mattmatteh wrote:
does the 6502 have an internal register for indirect addressing modes to store the pointer?

Yes. There has to be at least some register fed to the internal ALU to allow the effective address to be built up. Why do you need this? Are you doing a state-machine implementation of the 6502?

Quote:
also, is there an internal register to hold the address for the address bus?

How to answer this in the most helpful way depends on what you are trying to do.

Author:  mattmatteh [ Fri Oct 06, 2006 9:48 pm ]
Post subject: 

the cpu core works in my emu, i was just making some changes and cleaning up some stuff. i figured the 6502 has those registers and i was going to match that in my code. i know the hardware doenst have to be exact, but i have those variables anyway.

i took a cpu design class several years ago, so i understand most/all of the 6502. just need to refresh some of it.

thanks matt

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