PSX compatibilty

[rama]

Before we get to timing, we have to get the hardware right.
There are major issues with the PGIF. It only works on assumptions and a huge buffer hack right now.
Fixing this requires more reverse engineering and testing. It's a huge project to get this information from
the hardware, because it is so inacessible.

But yeah, the timing is also bad, as you noticed. The effect of that is a few games not booting or hanging.

It isn't the big problem though. That's the PGIF.

[Nobbs66]

@Rama, are there any plans to add support for the Load Delay on the IOP?

[rama]

What load delay?
On plans for PSX, I'm actually hoping for someone to come out with something (again ).
This PGIF stuff should really be looked at first. Well, that and whatever we're doing with SIO / SIO2.

[Nobbs66]

What load delay?
On plans for PSX, I'm actually hoping for someone to come out with something (again ).
This PGIF stuff should really be looked at first. Well, that and whatever we're doing with SIO / SIO2.

On MIPS 1, loads take 1 cycle before the data is pushed to the specified GPR.

[Konoko56]

Update: Enabled the Delay VIF1 Stalls (VIF1 FIFO) hack with all fix I had cited before (EETimingHack , IOP interpreter , software mode OpenGL) fix some emulator crash and made Crash Bandicoot 3, Yu-Gi-Oh! FORBIDDEN MEMORIES and 007 Tomorow never die playable without crash.And the GIF FIFO help sometimes.

[hellbringer616]

Found a neat video explaining how the PS1 functions on a fairly basic level.
https://www.youtube.com/watch?v=MPXpH2hxuNc
Hope it helps development. EPSXE/PCSXr seem to be dead, You are the future!

[Nobbs66]

it's cool, but I wouldn't say it's terribly useful as it doesn't cover any specific hardware details.

[hellbringer616]

I figured as much, seemed more about how the chips function with one another rather than how they actually function.

[Sacr1fIces]

Found a neat video explaining how the PS1 functions on a fairly basic level.
https://www.youtube.com/watch?v=MPXpH2hxuNc
Hope it helps development. EPSXE/PCSXr seem to be dead, You are the future!

is EPSXE actually dead? i was planning to emulate ps1 games in future and this was like a bucket of cold water on me.

[refraction]

I wouldn't say EPSXE was dead they made a release not long ago.