At the moment, I wouldn't know of any software tests that would be interesting to run on a real 5903. But it would be nice if you could test it with a normal VCD, for confiming if it does accepts CDRs, and if it does have an OSD layer. Yeah, it has an OSD - it's the typical crude "primary and ...

What is the Philips chip? I'd have guess that was video related. I'd laugh if it's an osd generator that outputs composite and the 6230 decodes that to rgb. One of the chips might be an amp or voltage convertor, which should be pretty simple to figure out if you stick a scope on it. The Philips chi...

And I don't think it's chromakeyed - I can't see any sign of the PSX video being fed into the VCD board, so my guess is that once it switches over to VCD mode everything (including the OSD) is generated by the Video CD controller chip. The PSX video wouldn't need to be fed to the VCD board for chro...

Oh, and there was one other thing I missed in my summary - there is another mux (4053) on the board located next to the audio DAC (it's visible in the photo of the boot ROM). From the look of it, it switches the DAC from the PSX SPX to the I2S output on the VCD decoder chip. And I don't think it's c...

OK, Here it is

SCPH-5903 NTSC:J

Board PU-16 1-665-191-11 w/sub board MP-45 1-665-192-11
Chip markings: C 4021 / SC430924PB / G63C 185 / JSAB9645C

It's hard to tell - I haven't really seen enough of them to reach a clear conclusion. What I have figured out is this: PU-7 and PU-18 have both inputs linked. So do PU-20, PU-22 and PU-23 (they have different clock circuits, though). The early PU-8 with VRAM has both inputs linked. The later PU-8 wi...

Some of the debug consoles don't have the oscillator hooked up to both inputs, so if you display the wrong one then you get no image at all. This is true for some NTSC retail consoles, too - I've had a couple of SCPH-1001s that would simply lock up when you selected PAL mode (they stopped generatin...

ady05113 wrote: As long as it plays in colour that good enough for me. Hate to play in black and white lol. Thank you for helped me out. But first i must buy you a cup of coffee. It that okay?

Sure, but there could be some practical problems - like the fact that I'm in Hong Kong

Thank you for a long explanation guys. Yeah, lesson learnt lol. Luckily i have extra PSU from a broken console and its rated with 250V. I will replace the capacitor for the broken PSU soon. Just one quick question. Lets say if it pops@blows up while the 7 or 5 pins cable is connected to motherboard...

Yeah, the mod is simple if you have the correct PU-8 to do in on - which luckily you did (the early PU-8 version with the old GPU and VRAM doesn't have those pads). The approach I used on the PU-18 in the document posted in this thread is electrically the same, but more fiddly because the PU-18 only...

OK, you have the right board to install the PAL/NTSC mod using the traces already on the board. The mod is pretty simple - you just remove the oscillator module and the 3 SMT parts just above it and them install them on the PU8. The cap goes on the back of the board and you also need to remove a zer...

Can someone explain what is going on here? :shrug Yeah, the input filter cap on a Japanese power supply is rated at 200V, so when you connect the board to European mains (nominally 230V AC RMS) then it tries to charge up to the peak line voltage (230V * sqrt(2) - about 325V) - since it's only rated...

Hi, nice tutorial there. Just one quick question. I have a broken PU-7 board can i take the oscillator and swap it to my (SCPH-1002) PU-8 board ? Do i need to swap the resistor too? Yeah, you need the resistor, RF choke and caps - but depending on which PU-8 model you have there might already be sp...

Very nice mod and simple, but it would be useful to report which SCPH models has (or uses) a PU-18 ? Best bets are SCPH-5500, SCPH-5501, SCPH-5502 and SCPH-5552. If you have a SCPH-700x machine then it's worth checking because the early production used the PU-18, although most of them are PU-20. Th...

@ TriMesh in the " PU-18 RAM mod.pdf " file in the " Parts and tools required " section you mention that 4 x KM48V2105AJ-6 are required, may I assume it's a typo? Well, spotted - yes, that was a typo - the correct P/N is KM48V2104AJ_6 https://www.psxdev.net/forum/download/file.p...

I'm going to guess that going from 8 to 2 MB RAM for retail units was a late decision in the design of the PSX. It'd explain the use of a hack, but isn't conclusive. This is kind of like how the SNES probably had 128 KB of VRAM until late in design they dropped it to 64 KB. The SNES VRAM was word-a...

in caetla the :circle button is for validate the selection, and the :cross is for cancel. it's confusing, as in the games we are used to use :cross for validation and :circle for cancel. It's because the guy that developed Caetla was Japanese, and that's the convention they use in the Japanese game...

OK, here's another one for the collection:

SCPH-9000 (NTSC-J)
PCB: PU-23 1-674-987-11
Chip markings:
C 1060 SC430942PB G63C 185 SSAQ9920A

Edit: the archive file name (and the name of the file inside) was wrong, and has been changed - the actual file contents were correct however.

From one of my friends:

SCPH-1001 late PU-8, PCB number 1-658-467-23 - chip markings are C 2021, SC430918PB, G63C 185, JSBM9633B

Dumped it - and it's exactly the same as the psxdev.ru dump.

OK, maybe not that useful, but I thought I would pass it on.

When Sony designed the PSX GPU, it had provision for operation in both PAL and NTSC modes, and had a separate clock input for each mode. However, the retail consoles had regional lockout and were only capable of playing software from their region, and hence only in one video mode. As a result, Sony ...