I'm looking for an NTSC Playstation to install the PSIO on, which is more or less a flash cart for the Playstation. To do this, the Playstation needs to have a parallell port, which was removed on later models since it was only used for piracy-related things. I have consulted Wikipedia's chart on comparison of Playstation models ( https://en.wikipedia.org/wiki/PlayStation_models#Comparison_of_models
) and decided to select the last Japanese model that had a parallell port, which is SCPH-7500. I have been told that the PSOne had better RGB-encoders and therefore better image, and I assume that the newer the original Playstation is, the better the image should be. However, on the chart it also states "Major manufacturing cost reductions took place from this model onwards.
The number of memory chips and CD-ROM controllers were reduced, other components were simplified, especially on SCPH-750x.", making me want to consult /vr/ too regarding this.
tl;dr What Japanese revision of the original Playstation with a parallell port should I get?