So I've picked up this DTL-H1002 from eBay for around £100 and was in a right state when I got it. I carefully disassembled it in hopes to clean it out and replace the rusty shielding and noticed something that I wasn't expecting... So is this a Normal PS1 main board shipped in the Blue Dev case?
Hmmm, what does the MODEL NUMBER on the Main board say? It seems that u might have a modded PS1 in a Dev shell!
Check the boot screen with a game (cdr or pressed in/out of region) and look for http://2.bp.blogspot.com/_w86OiaE0IQQ/SIL4Sh63WmI/AAAAAAAAAHM/OOLczugZZCo/s400/PSOne_Boot_Screen.jpg the SCEA/SCEE/SCEI initials at the bottom of the screen - if they are present it is not a real debugging station.
Well I've gone ahead and booted up a US retail pressed game and it is missing the SCEA mark at the bottom. Assuming this is a real Debugging Station console, what is this modification on the board? I can't imagine Sony releasing this unit with a fragile PCB wired to the board in this manner.
Sounds like what you've got there is pretty unique. The board looks like it's fixing a defect on the main board.
It looks like a real debug to me - the primary difference is IC304, which is a mask programmed part in a retail console and a OTP EPROM based one in a debug. That 68HC705 is one of the programmable parts, so it's correct for a debug console. The fact it's an engineering sample part (XC prefix rather than MC) is unusual, though - it's the first time I've seen that. It's also got a 9408 date code (1994, week 8) - which makes it about a year older than any of the other chips in the photo. It's hard to be sure without better photos, but I think that little board is a voltage regulator that was added to clean up the supply to the analog parts of the CD player. This regulator was on the PU-8 boards, but not the PU-7, so it's possible that this is the prototype version of it. I can't remember ever seeing that string displayed on a debug. On the console I have handy here (DTL-H1202), that space is blank no matter what sort of disc you boot on it - I tried CD-Rs and originals from all 3 regions.
Wow.. Ok I'll try get some better pictures when I get a spare moment, I'm curious to find out if there are any more oddities on this board!
Would you be able to dump the bios? There's a chance it might be an undumped one since there are other oddities on the board.
I could remove the chip from the board although my skills tools may be a bit insufficient and Unfortunately I don't have anything to read the Bios chip. However I've looked into passive ways of dumping it and found this: http://ngemu.com/threads/psx-bios-dumping-guide.93161/ I have a PS2 with Free MCboot on it as well as Memory cards and a pen drive! So hopefully yes.
OK, even without better photos, I had another look at it, and I'm pretty sure that what it is. This is a standard PU-7 board from a SCPH-1000 - you can also see what the retail mechacon CPU looks like on this board. http://wiki.assemblergames.com/lib/exe/fetch.php?media=wiki:sony:pcbphotos:pu-7_bottom.jpg If you look around the RF amp chip (CXA1782BR, IC702) there are some obvious mods on your board - Q709 has been moved to the right, an extra cap added near the C759 location and what appears to be a site for an additional transistor just to the right on the added PCB. If you look at an early PU-8, you can see the added SOT23-5 part (like the one on that added PCB on your board) between the RF amp and the BTL driver (closer to the BA6398FP) http://wiki.psxdev.ru/images/4/41/PU-8_sideB.jpg So my guess is that the tried to fix the problem with noise getting into the RF amp by adding a little single transistor regulator to the board (the location the wires to the little board are soldered), but it didn't provide good enough performance, so they changed to that 5-terminal integrated regulator and had to design a little mod board to install it. The regulator was then incorporated into the PU-8 PCB layout.
Finally managed to get some in focus pictures of the board: https://drive.google.com/file/d/0B9aauzL079BMRkZNRFdWeVdxWmM/edit?usp=sharing https://drive.google.com/file/d/0B9aauzL079BMcXF1Ykk5Q3ZOMVU/edit?usp=sharing https://drive.google.com/file/d/0B9aauzL079BMYkRBMzNjaEJWMW8/edit?usp=sharing EDIT: It's actually a PU-8 board, I've put up a close up of the smaller PCB as well. I'll be dumping the BIOS a bit later on.
That appears to be a PU-8 prototype board. It has the CXD2510Q CD DSP (like a PU-8), but still has the CXD1199BQ CD decoder chip (like a PU-7) - the production PU-8 boards had a CXD-1815Q. It also has IC301 installed and the RGB buffers (with the associated caps near the rear panel) - both things that the PU-7 had but the PU-8 didn't. The boot ROM (IC102) is an OTP EPROM rather than a mask ROM. It also has a solder side silkscreen (which is why I assumed it was a PU-7 from the first photo). This suggests strongly that it's represents the first stage of the development of the PU-8, before they updated the CD interface chip and went into cost reduction mode. And that photo of the subboard also tends to confirm my theory - the device has the same shortcode (C9) as the regulator that was added to the production PU-8, and all 3 of the connections I can trace with confidence from the photo go to the same places (the other two *probably* go to the same place, but I can't be sure because the traces are obscured by the little PCB and the wiring). Incidentally, the use of an EPROM on that board makes it quite possible that it has a previously undumped BIOS.
Finally managed to get the BIOS dumped. Is there any pictures of a regular DTL-H1002 Mainboard anywhere? View attachment DTL-H1002.zip
I have some somewhere - I will try and dig them out. But in general Sony just used whatever boards they had handy and swapped over IC304 for a debug one, so depending on when it was made it could have quite a few different basic boards in it. It generally went like this, though: DTL-H100x : PU-7 DTL-H110x : Old (VRAM based) PU-8 DTL-H120x : New (SGRAM based) PU-8 * * Green cased unit that will always have a board with SGRAM in it. All the NTSC:J and NTSC:U/C units I've seen have had standard production mainboards in them, just with the mechacon changed.
