>I'm going through Nick Bensema's "How To Draw A Playfield" but am not
>getting very far. On page two, it lists a command that reads as
>follows:
>
>STA 0,X
>
> I thought STA stored what followed the command, from memory
>location or actual number, in the A register. The book on 6502
>programming didn't mention anything about a comma like that. What am I
>missing?
That's indexed addressing... what it does is store the byte in A to the
location (0+X).
> Also, just before it mentions that command, it mentions:
>
>"Since X is already loaded to 0xFF, our task...."
>
> What is 0xFF? That lower case "x" is what's throwing me. Is
>"0xFF" referring to location FF on the zero page?
0x before a number means that the number is in hexadecimal... with the
6502, the more common notation is to put a $ before the number. So, since
X contains $FF (decimal 255), that above instruction stores A to location
255.
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