Hello All, I don't post often but be sure I always follow the work of everybody, and I must say it is a never ending amazement.
So , of course, I have a subtle hardware related problem, which brought me here:
I'm pretty close to modify one of my copper/blitter based demo so It would adapt every effects to the european PAL (50Hz, 256 scanlines) or NTSC video mode (60Hz, 200 scanlines)
... I've been using a little old code example "to check for Pal or NTSC" that does this:
move.w $dff000+vposr,d0
and.w #$7f00,d0 ; chip version bitmask
cmp.w #$2300,d0
beq.b .agaPal
cmp.w #$3300,d0
beq.b .agaNtsc
.. so on my UAE I have a ntsc checkbox that makes it work.
... But of course I also code and test on Pal Real Amiga 1200, and there is this boot issue: in the "2 mouse button startup", you can force NTSC or Pal at this level. But then my demo will run in 60Hz and the test always return Pal: no surprise, it is a "Chip version", it will not change in ntsc mode. So what I have to find is how to check the pal/ntsc information given at boot.
"problems you don't have with OS legal intuition screen demos"