18 Nov
2000
18 Nov
'00
9:37 p.m.
time it wants
to do DMA (this is part of the reason why sprites turn off
automatically when the Kernal LOAD routine starts), which interferes with
the exact timing the IEC bus protocol demands. To get this speed boost
back, you send the drive a UI+ command, and then turn the 64's screen off
with POKE 53265,11.
That is interesting. On the Atari 8-bit, turning off DMA turns off video.
You get a 30% speed increase by doing this (poke 559,0). Drive access
does not do this though it's tricky to do both video and heavy i/o at the
same time. This was fodder for lots of demo's that did sound, disk, and
video at the same time.