Exec permit and forbid functions (taking over the machine ;) ...)

[Jose]

Hey dudes;) I was fiddling around with some stuff and got this doubt, you know me, lazy and without much time, so I decided to ask you this (I'll probably look into it myself anyway but...) for quicker results:
I want to stop multitasking and take over the machine to writte my own copper list and mess around with the data fetch registers and playfield pointers, modulo and ham and that type of stuff;) To prevent other tasks from interfering and screwing everything I read that I need to use the Exec forbid function. At the end of my prog I use permit func to restore multitasking.
But...
Will this restore the register I been messing around with to their initial values? Many registers are writte only, so does this means that the OS stores a copy of their values somewhere?
If this doesn't restores the register values how can I do it?
What else should be done to restore the "initial" state?

Thx & cheers

[Jose]

Nice! I'll have to look more into some stuff though, mainly system control hardware. So far I've only read the playfield, copper, and part of the blitter chapters on the HRM... This is getting me more trouble than I thought, you're all insane :O

[Jose]

Hi! Just out of curiosity why do DMACONR, INTENAR, INREQR and ADKCONR, have to be or'ed with $8000 :-?

I know there are some addresses on the custom chipset's registers that are not needed to be writte fully, cause it's the custom chips that are woking with them and they have a more restric address area. But the since the contents of the registers are to be placed on the very same registers later on, why do they need to be or'ed :-?

[Jose]

Ok, dunno if anyone cares but I already knew the answer... Remembered this night when I woke up at 5:30... don't ask me why :lol:
Bit 14 of those registers works as the set/clear bit. If it wasn't a 1, the other set bits would be cleared.