UAE questions (Programming)

[xArtx]

Hi Guys,
After looking at UEA source, I have a few questions regarding UAE and
emulators in general.

Why are they still scratching physical media to use floppy disks rather
than loading the disk into an 880k array and reading/writing there until
it comes time to exit, and writing the whole disk array where the bed
is already laid (even if you want to maintain original drive timing)?

When an emu takes a game snapshot, it is simply saving the contents of the
Amiga's chip and fast memory, and restoring it at run time?
Couldn't you load a game faster that way, bypassing the initial disk access?

Is the difference between emulated Amiga models purely imaginary
(dictated only by the CPU and other hardware you select)?

On the Amiga side, when you talk to Paula, do you just tell the chip the
start and end address in memory of the sound sample you want it to play?
and then set some register to start playing the sample?

This is a cross-post from Amiga.org, where it was suggested I take
programming related questions here...
That's probably enough for now
Cheers, Art.

[Toni Wilen]

Originally Posted by xArtx

Why are they still scratching physical media to use floppy disks rather than loading the disk into an 880k array and reading/writing there until it comes time to exit, and writing the whole disk array where the bed is already laid (even if you want to maintain original drive timing)?

I don't know. It has always been like that.

When an emu takes a game snapshot, it is simply saving the contents of the Amiga's chip and fast memory, and restoring it at run time?

Thats the easy part. Difficult part is to save everything else, custom registers, CIA registers, state of other hardware etc..

Couldn't you load a game faster that way, bypassing the initial disk access?

Saving state after initial load has been done? Yes but then it is locked to current configuration only.

Is the difference between emulated Amiga models purely imaginary (dictated only by the CPU and other hardware you select)?

There are also lower level differences, like memory mapping (for example CIA address range, chipset mirror areas)

On the Amiga side, when you talk to Paula, do you just tell the chip the start and end address in memory of the sound sample you want it to play? and then set some register to start playing the sample?

Yes, more or less.

[xArtx]

Thanks.

I'm sure I'll have more as time passes