Possible to kill the background OS with Blitz?

[earok]

Basically, if I have a game where quitting back to the OS is unnecessary (such as one that boots from floppy or on CD32), is there a way to kill the background OS to free up a bit more memory?

[Daedalus]

Not really (I presume you mean as distinct from suspending it with Blitz mode), but if you boot directly from floppy there's very little of the OS actually in RAM. How much memory are you stuck for? Just about the only thing I can think of that might take a chunk of RAM is disk caches for any attached hard drives, which is why you had to disable partitions in the early startup to get some games to run from floppy.

[earok]

Originally Posted by Daedalus

Not really (I presume you mean as distinct from suspending it with Blitz mode), but if you boot directly from floppy there's very little of the OS actually in RAM. How much memory are you stuck for? Just about the only thing I can think of that might take a chunk of RAM is disk caches for any attached hard drives, which is why you had to disable partitions in the early startup to get some games to run from floppy.

Cheers, I was really just hoping to squeeze out anything I could get - if it was fairly easy to do so. I didn't even think about the fact that I switch in and out of Blitz mode during the game (for loading etc) so it'd be more trouble than it's worth

[Daedalus]

Yeah - you'd most likely need to write your own custom loaders in that case - not impossible of course, many games do that, but you'd really need a good reason to do it that way IMHO.

[idrougge]

Isn't there a CloseWB command or am I thinking of AMOS?

[Daedalus]

Yep, there is indeed, but if you're booting from floppy you're probably not going to bother opening the WB screen in the first place. Good point though - that'll free up a screen's worth of chip RAM if it does open - about 41KB.

[Coagulus]

There used to be a startup-sequence command (add44k?) which used to help i think.

[Daedalus]

Originally Posted by Coagulus

There used to be a startup-sequence command (add44k?) which used to help i think.

Indeed there was, Birds of Prey used it during loading/decrunching. It appears to add the Workbench screen's memory to the memory pool, because as it loaded, it would gradually corrupt the screen from the top down. Interesting technique - I thought it was something they'd written especially for BoP, but maybe it's available elsewhere too...

Edit: Reading about it now, I see that it removes a bitplane from the screen and frees up that memory, so maybe the corruption is something else related to the BoP unpacker. Anyway, worth a look if you're super tight on RAM.

[daxb]

If I remember right there also exist add36k and there were some more commands that do similar things. My 25 years old Protracker floppy disk starts a command called "moremem" to get as much chipram as possible.