PlayStation Development Network

I do not know where this should be posted (feel free to move it) but I recently obtained a DTL-H1001H and noticed that nobody appears to have dumped the BIOS for it yet. I have therefore done this using shendo's BIOS Dumper CD and a PSX-SERIAL USB cable. I have no idea if this is a unique BIOS or not, but I have observed the following:
This console's motherboard is labeled as a PU-8, yet it also has a dedicated S-Video out port. It boots up with the main menu in english as opposed to japanese, and plays NTSC games in colour, but not PAL games. Therefore this is an NTSC board. Analysing the BIOS ROM using a Hex editor shows similarities between the SCPH-1000 BIOS ROM, but that bios is japanese. It is therefore entirely possible that this is a previously undumped early US "hybrid" BIOS. The actual BIOS ROM IC (and the CD-ROM mechacon IC) appear to have been replaced after the board was already manufactured, as they have the tell-tale yellow residue around them. I have some badly done photos of the main board (sorry, only have my phone camera) if you wish to see these. I have observed a strange additional circuit that looks like it has been manually soldered in on the bottom of the board. No idea what this is for...
EDIT: On the TV, the BIOS Dumper program displays the CRC as 55847d8c, version 2.0. I have therefore taken a photo of this as well. Looking up the CRC 55847d8c, it looks like this BIOS is identical to a DTL-H1001 BIOS (same but without the H on the end). Oh well, at least it can go on record! I have no idea if any of this information is useful to anyone, hopefully it will be!

They replaced the HC05 with one that was programmed with the security stuff removed. Sony would have had a stock pile of them at the time and they just swapped them with generic PU-8 boards. The chips can still be bought blank from suppliers, so in theory, they could be programmed with the ROM that was dumped from the debugger (available as a download on the forums) and swapped on a PU-7 or PU-8 unit just like yours. Debuggers are nothing special

That little mess of wires look like some sort of colour mod.

Yeah, I am aware that the HC05 IC can easily be swapped out with a hot air station (did this myself not so long ago from a broken DTL-H1000 onto a generic SCPH-1000 PU-7 board because the audio circuit appeared to be corroded).
What is strange is that I've never seen a PU-8 board with dedicated S-Video output, and 40pin BIOS ROM IC. I've only ever seen those on PU-7 boards.

Yeah, the board is unusual. It doesn't have the retail "sub" numbering (PU-8-11, PU-8-21, PU-8-22 or PU-8-23).
It's using the PU-8-11 design though, including old GPU + VRAM and a single oscillator slot.
It's probably an in-house early PU-8.
Additionally, the missing S-Video components have been restored.

Hm, I don't think the extra module is for subcarrier mods. The location would be weird as well.
It looks more like a CD fix?
Since the Mechacon is replaced, the fix is probably not related to security, but maybe a board flaw.

I've got a PAL PU-8 with the 40-pin HC05, but no S-Video. You's seems to be the Japanese model though, so that makes sense.

Hmm, could be! It looks like some sort of regulator or transistor. It's hard to tell if it's going to alter the video IC or motor driver IC. The photo is too blurry.

Hmm, so this could be a prototype board intended for internal Sony use, that makes sense. I will try to take some better photos tonight, I'm going to be rehousing the unit anyway. The case is very brittle on the top. From a user perspective, the late PU-8 boards with the SGRAM GPU and space for two oscillators (both PAL and NTSC) are probably more desirable. However, from a developmental history perspective, I do think it's worth gathering information from this earlier (and apparently undocumented) board so I will do my best.