At 03:56 AM 7/20/99 +0200, you wrote:
>Is it possible to execute BDOS / Disk BASIC disk operation with interrupts
>disabled?
Yes.
>Do those functions embed EIs?
Yes.
>Should I disable interrupts accessing the VDP register directly?
You don't have to, but it does solve the F700 slowdown.
Or do you mean "should I use OUTs rather than a BIOS call"? In that case,
it doesn't matter. I use OUTs but Konami uses BIOS calls.
>Is it legal to call 256 times #FD9F with interrupts disabled at VDP level?
Yes.
The VDP is only accessed by the interrupt handler in the ROM, which decides
whether it should call both #FD9F and #FD9A or only #FD9A. #FD9F is only
called on normal VDP interrupts, not on line interrupts or interrupts from
for example MoonSound.
So, if you call #FD9F, there is no problem, since routines on that hook
won't check the VDP interrupt status anyway. If you would call #0038 256
times, things wouldn't work.
>Is it legal to tell Disk ROM to stop the motor with VDP interrupts disabled?
Yes.
Bye,
Maarten
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