On Jan 17, 2017, at 21:56, Systems Glitch via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
I need a book that reeeeeeeeeeally simplifies the concepts.
Do remember you're trying to make a CPU do your bidding at the machine language level :)
Take a look through the book I recommended ("Programming and Interfacing the 6502, with Experiments," Marvin L. DeJong). You can find PDF copies of questionable legal standing all over the Internet. I wouldn't be surprised if we have a print copy somewhere in the museum, but it's usually a very cheap book anyway.
Don't gloss over the parts about hardware organization. It's important. If you don't understand something, ask questions.
Seconded. The thing to remember is that, at its core, a CPU (especially one as simple as the 6502) is a pretty dumb machine. All it does is fetch an instruction from memory, perform that instruction (which is usually along the lines of "add this", "load this from here", "store that to there", "jump to this instruction", etc.), then load the next one. The CPU can't do too much; it's just a fancy calculator. I'll be happy to give you a little tutorial tomorrow evening if you want. Assembly and machine language have a reputation for being difficult, but really it's probably the simplest part. The difficult part is working out how the low-level concepts (add/subtract, load/store, jump, etc.) map to higher level concepts (loops, text output, functions, etc.). That just takes practice. - Dave