My noobiest question yet
say I type this code



does this act as a pointer to memory location FFE0 or does it use FFE0 as a value that I can write into a memory location

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JMP $FFD2

LDA (LoaD Accumulator register) is precisely that-- a load. It does not store anything in memory-- ever. LDA $FFE0 reads the contents of address $FFE0 directly, and puts it in the accumulator. If you want to read the contents of the memory location pointed to by what's in $FFE0, that would be an indirect written LDA ($FFE0). Actually, that addressing mode doesn't exist for the LDA instruction in any of the 65-family processors, but the more typical use would be that the address would be in zero page, so you would do for example LDA ($E0) (which does exist), where $00E0 and $00E1 could be the 16-bit address to any other part of the memory map. ZP is kind of like 256 bytes of processor registers, having special significance, and more flexibility than the rest of the memory map. Indexing would be the next step when you're ready for that.

After the number is in the accumulator, yes, you can of course store it to a location in the memory map-- but that's with a different (STore) instruction, not a LoaD instruction. (I say "a location in the memory map" because it doesn't have to be memory. It could be I/O.)

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http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Hi James,

I see you're posting a lot of questions (which is good), but it's pretty clear all of this is really new to you.

You would probably be well to try your hand at a little assembly language, and learn how the 6502 works at a machine code level (it's architecture, memory maps, addressing modes, zero page, the stack, interrupts, etc.) before you start buying chips and wires and what not.

There are lots of 6502 simulators available, even some that run in a web browser. There are lots of assemblers available. You can work within an Apple ][ or Atari, or C64. You can find some that are the simplest of 6502s, etc. Play around in that domain for a bit and get a feel for things before you move farther. Getting an understanding of 6502 machine code and assembly will give you a very good foundation that will make the CPU schematics and computer design much more clear when you get to that point.

ive done x86 for forever

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JMP $FFD2

I can't pass up the opportunity to recommend the excellent programming manual available on WDC's website, "Programming the 65816 including the 6502, 65C02, and 65802" by David Eyes and Ron Liechty.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

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x86?  We ain't got no x86.  We don't NEED no stinking x86!