i think i have almost gotten this whole horizontal positioning business
down except a few minor points...
1. in the stella document it says, and i quote:
"for example, if the electron beam was 60 color clocks into a scan line
when RESP0 was written to, player 0 would be positioned 60 color clocks
"in? on the next scan line.Whether or not P0 is actually drawn on the
screen is a function of the data
in the GP0 register, but if it were drawn, it would show up at 60."
does this mean that i can position an object and perform a reset for the
player/ball/
missile and it will show up on the line FOLLOWING the scan line where
the
reset was performed (at the interval where it was reset)?
2. if the HMOVE command has to be performed following a WSYNC, how does
one place objects on the far left side of the screen and move them
relative with the
horizontal movement register if, to store a value in memory, takes 3
cycles (9 pixels)? i would not need to actually write to the horizontal
movement registers
because i figure i can obtain the position and relative movement needed,
during the
housekeeping part of the program (which would be in non-picture
lines)...
3. this one doesnt really have to do with the horizontal movement...but
if i write to the playfield registers during the actual scan line at
different times for each register and leave playfield reflect off, is it
possible to actually make a playfield thats longer
than 20 bits?
dee
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