PlayStation Development Network

Hiya!
as per topic, is it possible to do a hardware conversion so that a PAL psx console becomes identical to a NTSC one?

TIA for any info/help!

I'd be interested to know this too. As far as I know you need a dual oscillator to replicate the different clock signals for PAL & NTSC

Yes, it's possible. If you want a true NTSC system though, you'll need to change the crystal oscillator and the BIOS. As for the HC05, don't bother. Just modchip it.

To fully convert a PAL board to NTSC (and vice versa) you would need to swap two or three components from a donor board. The BIOS ROM IC (as this sets the default boot colour mode) the oscillator to generate the right frequency and the CD ROM firmware IC (if you want to run original discs without a modchip fitted, as this IC determines which region type of disc to accept). There are ways one can have two oscillators fitted on late PU-8 boards onwards, as the GPU fitted to these boards has inputs for two oscillators. However Sony normally only fitted one, except of course the late PU-8 as this stage of the production was when the Net Yaroze consoles were produced and were designed to be multi region, so these boards typically have two spaces with only one occupied (unless destined for a black case, in which case both were installed). PU-18 and above only have space for one and Sony simply connected both oscillator input pins on the GPU to the same oscillator. You can work around this but it requires a bit more involved work, Trimesh published the details for this kind of mod here:
http://www.psxdev.net/forum/viewtopic.php?f=47&t=628 included in the same thread is details on how to go about adding the missing oscillator to a PU-8 board.