> PSX = the short for Playstation and that means mostly the original one>

Thats only part of the answer.

PSX is also a popular nickname for the original PlayStation video games console. The "X" appears because Sony originally developed the PlayStation as a CD-ROM and SNES hybrid unit. When the project was halted by Nintendo, Sony decided to redesign the PlayStation as a stand alone console, which was known internally as the PlayStation Experimental. The media caught wind of the name and it has stuck ever since.

ALSO PSX stands for:

PSX is the name of a Sony media center, digital video recorder, and DVD recorder based on the PlayStation 2 video game console. Since it was designed to be a general-function audiovisual device, it was marketed by the main Sony Corporation (whereas SCEI markets the corporation's specific game-related hardware). It was released in Japan on December 13, 2003

http://en.wikipedia.org/wiki/PSX_%28DVR%29