PSX terms

[abrahans]

Hello friends,

Do you know a site where I can learn about PSX terms? For example, ePSXe 1.51 has subchannel support, but I don´t know what is this. Also don´t know what is SIO IRQ, SPU IRQ, CDDA, and others.

If you can help me, I´ll understand the things better.

Thank you a lot

[3x3cUt0r]

try reading the documentation of the emulator ....

[sithspawn]

try checking the \docs folder on your epsxe base dir

[abrahans]

Thanks, guys.

I´ve read some of then, but unfortunaly they´re not very specific about what are these terms. Maybe, these terms are deeply tecnical for us to understand.

[Kane]

SIO IRQ is something to do with the Input/ Output controller IIRC.
SPU IRQ Hack is to get around a peculiarity with the Playstation's Sound Processing Unit. IRQ means interrupt request.
CDDA: Compact Disc Digital Audio.

[Badaro]

Originally posted by Lord Kane
SPU IRQ Hack is to get around a peculiarity with the Playstation's Sound Processing Unit. IRQ means interrupt request.

Pete put a nice explanation SPU IRQ in the docs of his SPU plugin... I'm quoting it below for those interested:

Well, MGS is heavily using SPU IRQs... one of the harder
to emulate psx spu features. What is a SPU IRQ, you may
ask? Basically the game is setting a special point (irq
address) in the spu sound, and if that point is reached
the spu has to report it back to the game, so the game
has the chance to upload new sound data (or to do whatever
it wants/needs to do).

Main problem in emulating spu irqs: the spu plugins are
running asynchron to the main emu (only the internal
epsxe spu is working in a more synchron way, afaik), so
the timing (which is important in emulating the irq) is
hard to get right.

(Side note: personally I prefer the async mode in spu
emulation, that way the music can play on even if the
main emu is getting very busy, for example on heavy cdrom
access when loading a new game level...
synchron spus tend to run out of sound data on such
occassions, causing cracks in the music.)

Oh, well, back to the spu irqs: what will happen, if the
spu irq timing is messed up by the spu plugin? Usually the
sound simply stops (the game isn't uploading new sound data).
But some games (like MGS) seem to get very confused, and
the whole game hangs. Because of that issue most main emus
have some "SPU IRQ" option, when that one is enabled (epsxe)
or disabled (fpse) the main emu doesn't care if the spu plugin
is doing the irq job, instead the irq signal will be always on.
That way the game will never hang, but of course the sound
(and sometimes the game timing) will be screwed.

[]s Badaro

[REi_FoX]

Pand remember youre playing a game on a different hardware so dont expect to much