What does it do?
It features 3 built in songs (to check your speakers), a dead pixel checker and controller button state tester.
How to use it:
To use it on your system, you burn it to a CD-ROM like any other regular PlayStation 1 game.
Make sure you burn at the lowest speed possible, 1x being the best.
You will need a modchip in order to boot it (or you may do the swap trick).
Information:
Please take notice that it is only version 2.2 (last updated 6th JUNE 2012).
If there are any bugs, please let me know and I will fix them.
To see more information about the tool, please see http://psdev.psio.com.au/homebrew.html" onclick="window.open(this.href);return false;
It features auto region detection in the code, so it should switch from PAL to NTSC perfectly fine.
Download:
http://psdev.psio.com.au/homebrew/files/psxtest.zip" onclick="window.open(this.href);return false;
Screenshot:

If you are interested in programming and making stuff for the PlayStation 1, then be sure to check out http://psdev.psio.com.au/" onclick="window.open(this.href);return false;
Thanks, Haunted360