>> If you want to have real fun, change the block size and playfield data and
>> see what kind of pictures you can draw.
>
>okay, some questions.
>
>1.) is STA TIM64T some sort of timer?
Yes. The timer expires in A*64 cycles.
>2.) What does the STA mean?
Store the accumulator (A-register) in the specified location.
>3.) LDY #$08 ;how many scanlines is each block?
> LDX #$17 ;number of blocks of data. LDY * LDX = 192!
>
> Are these height and width values? I tried messing
>around with them and ended up with some pretty strange stuff.
LDY #$08 states how many scanlines in each block. Change it to 2
and the object will squish down. He could have said LDY #8 since using
hexadecimal really isn't important in this case.
LDX #$17 (#23) seems to state how many bytes are in the graphic.
I'm afraid the way his demo is designed, you'll have to arrange it so that
X*Y is reasonably close to 192, lest you cause the screen to scroll.
>4.) Is JMP essentially just a goto?
Yup.
>5.) LDX PF0
> What does this code do?
I don't know. PF0 is a write-only register.
>7.) Crackers, didn't you say you had a small program that would
>let you create graphics for the 2600 instead of having to use graph paper?
He said he thought of writing one. In fact, so did I. I think I'll wait
until I'm done with my C++ class, as I'm pretty sure this task would be
better suited to an object-oriented programming language.
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