ART100@psuvm.psu.edu (Andy Tefft) (10/07/90)
I'm still trying to port this windowing system. Parts of it
seem to work (I can get the main menu bar up). I found out my
macros for the BRA instruction were a little off, but I fixed
that problem.
My main problem now is the VBL. The program is set up to write
to the screen during the vbl cycle to avoid flicker. The event
loop contains the following code:
loop bit vbl
bmi loop
wait bit vbm
bpl wait
where vbl=$c019
If I remove the last two lines of that, I can move the mouse
around and select menu items (although everything blows up
once I do, but that's something to figure out later).
Why doesn't this work on my //c? I can't try it on my //e because
it's not enhanced (maybe I will try it anyway). My old assembler
runs under dos 3.3, but copying the binary to prodos doesn't
make a difference. Is the vbl different on a //c?
I just tried it on the //e and it won't even draw the menu bar.