PlayStation has arrived on the iPhone and iPod Touch!
According to ZodTTD, an iPhone/iPod Touch PSOne Emulator port of PSX4ALL is in the works!
Provided that BETA testing goes well, the author says we can look forward to memory card support in the initial release, along with full sound emulation.
A dynarec is also in the works, to get emulation up to a playable speed on the iPhone/iPod Touch's 620MHz CPU. Roughly speaking, the developer expects that about 75 percent of the PSOne's game library will be compatible.
To quote: What can you look forward to in the first release of psx4iphone? Depends on how the beta testing goes. I will be working on the existing dynarec (cpu emulation) quite a lot to improve performance as it will be required.
The screen scaling and screen placement will be drastically improved over the above images. Memory card support will work, and save states might work. Sound will be implemented as well. The interface/gui will be very similar to gpSPhone's just with 4 hard buttons instead of just A+B, and L2 and R2 buttons.
A rough estimate would be about 75% of games will be compatible. With such a large library of games, this may or may not include your favorite game. Performance will have to be increased about 25% to get a good portion of games running smoothly. This can be done.
I will be contacting those who donated to me (for gpSPhone and psx4iphone) when a beta of psx4iphone (also works on iPod Touch) is available. If there's a large amount of beta testers and the demand is there, it could be within a matter of days. :)