Speculator 0.9b:
This was the first emulator I found for Psx, the file has 20 games wich can´t be changed (may be by a brute force method). It emulate a Zx Spectrum 48 at full speed but without sound. The author wrotes me 4 months ago telling that the next version will have sound and the possibility of changing the games.
To use the emu you have to
put it on a Psx Cd changing its name by Psx.exe or using the shell.
