Just acquired a Slim PS2.....

[RARusk]

Recently I acquired a Slim PS2 (or PSTwo as some people have called it) in hopes of doing a RGB hack to it similar to the one I did on my Version 3 PS2. The PS2 RGB hack is to find the three RGB video signals just as it leaves the Graphics Synthesizer chip and the two sync signals (Horizontal and Vertical) as it leaves the SC44728 chip and tap into them so they can be routed to a monitor so I can avoid MacroVision, Component Video Forceback, and Sync-On-Green problems. I have had success but ended up damaging the nearby sync mixing chip, on my current unit, in the process. This means that my Version 3 unit cannot output anything but RGB Analog (not exactly a bad thing but not good either).

I originally had my heart set on a SCPH-50001 unit but, as Murphy's Law would dictate, when I got the money to acquire one I could not find one for the life of me. So I found a used SCPH-70012 unit at a local GameStop for about $140 (plus tax).

This unit was not as hard to deal with as the other ones (no long silver strips) but it was still a bit of a pain especially with trying to remove the drive unit. But I eventually got to the bare motherboard and started examining it.

On the older PS2s (SCPH-30001 and SCPH-50001 units) the Graphics Synthesizer would take the raw signals given to it by the Emotion Engine (CPU) and create RGB Analog signals. These signals would leave the GS chip and go to the A3525BR video chip for final processing. The A3525BR chip would take the RGB signals and make Component Video, S-Video, and Composite Video signals as well as route the RGB signals (if activated in the System Configuration area under Component Video Out) to the AV plug. The SC44728 chip (usually on the bottom of the motherboard) outputs the Horizontal and Vertical Sync signals which then go to a small 10-pin mixing chip which combines the two signals into Composite Sync. This chip also mixes the MacroVision copy protection signal into the Composite Sync when a DVD movie is playing. The Composite Sync then goes to the A3525BR to be mixed into the video signals themselves.

The reason the PSTwo is as small as it is is because they were able to condense a lot of functions into a smaller number of chips. The biggest one was to combine the Emotion Engine and most of the Graphics Synthesizer into a single chip. I hoped that when I started poking around the motherboard I would still be able to do the RGB hack that I had done on my current (V3) unit.

The first thing I noticed on the PSTwo motherboard that there was one big chip, the CXM4015R, that all of the video signals heading to the AV plug come from. Then I started looking for the sync signals. After awhile I found them where they entered the 4015. However, there were no junction holes on the traces that I could use to attach wires to. But, after further examination, I found alternate points near the main CPU/GPU chip itself. And they had junction holes too. Even better, the junction holes on the PSTwo motherboard were completely open and did not have any of the gunk that was on the previous revisions. I could just stick a 30-gauge wire straight through with no problems at all. I might not even have to solder it into place.

So far, so good. After tapping into the sync signals I went after the video signals. Sadly, this is where things went badly. On the older motherboards you could tap into the RGB signals as it leaves the GS chip to be processed by the A3525BR chip. But it doesn't work on the PSTwo motherboard.

On the PSTwo motherboard the raw signals leave the main CPU/GPU chip and head to the CXM4015 chip. Then the 4015 chip takes the raw signals and converts them into RGB signals. Then it converts the RGB signals into the other video signals plus it handles the sync mixing (and MacroVision mixing) and Sync-On-Green. There are no RGB signals to intercept between the main chip and the video processing chip. The CXM4015 handles everything inside. So the only RGB signals that can be found on the motherboard are the finished product and that means dealing with the usual assortment of problems when playing movies or doing Progressive Scan. Very disappointing.

So that means hacking at the CXM4015 chip to disable Component Video, Sync-On-Green, and MacroVision. I typed in CXM4015R into Google and came up with several pages. However, these pages involve the selling of the chip and none of them contained links to a datasheet. But that was better that what I got when typing in A3525BR or SC44728. So maybe somewhere I can find a copy of the datasheet for the CXM4015R for study.

Disabling MacroVision might not be too hard. Remember what I said that the mixing chip on the older PS2s also mixing in MacroVision when a movie is played. Well, if the trace for MacroVision can be indentified then it can be cut. MacroVision can't be mixed in if it can't get to the mixing chip. The sync channels on the PSTwo motherboard come from the main CPU/GPU chip. And maybe so does the MacroVision signal. If the trace for MacroVision that goes from the main chip to the 4015 can be found on that motherboard then it can be disabled. Unless, of course, that is handled exclusively by the CXM4015.

Then there was a simple hack to the A3525 chip that involved grounding one of the pins to disable Component Video. More than likely that won't work on the 4015. But then again it could but I would rather have a datasheet first before I start poking at the 4015 chip. And maybe there might be some way to disable Sync-On-Green too.

One other option is to acquire a VD-Z3 Component Video to RGB unit. I have heard a lot of good things about this device. However, the only places online where it is sold require some sort of credit card. I am a bit paranoid when it comes to using credit cards so I would rather prefer using money orders.

I am curious about what all of those dip switches do on the side of the VD-Z3 unit. I am also curious if it can also do 15Khz RGB. Of course, it is supposed to be used on standard 31Khz computer monitors. But I think it can output 15Khz RGB. It's just that nobody has tried hooking it up to either a Commodore 1084 or a dual sync (15 and 31Khz) monitor like the NEC MultiSync 3D. If it can output 15Khz RGB then the VD-Z3 is perfect for my MultiSync 3D. I can have the best of both worlds then.

But I would rather hack the PS2 to get it to do what I want. It is more fun, satisfying, and I learn more that way. Besides, I spent $140 on the damn thing and I really don't want to spend any more money at this time (unless I can find a VD-Z3 or a SCPH-50001 PS2 cheap). At the very least my PSTwo unit can output video signals my V3 PS2 can no longer do so I have a viable backup in case something goes wrong with that unit.

There was one more bit of irritation I had to deal with: the clock became stuck when I put the PSTwo back together and it would not unstick. When you get to the browser screen at startup you have the Browser and System Configuration options and those dancing dots to the left. When the clock sticks you get just one big blue ball that stands still. When you go into System Configuration to change the clock you can't get the numbers to move. I had the same problem with my Version 4 motherboard (which is practically ruined).

After a lot of searching I found a forum that had somebody with the same problem. It has to do with the system battery. If you remove the CR2032 battery, which keeps the time when the unit is off, the clock will die and reset. It may also become stuck when the unit is reassembled and turned back on. The solution is to go and play with the clock, try to get the numbers to change for example, for a few minutes and it will eventually unstick when you leave the clock option. I tried that and it works. Very useful for future PS2 hack work.

Sorry for the huge wall of text. I wanted to share my data and thoughts about the PSTwo and the VD-Z3. Maybe this will lead to solutions to some of my queries. At the very least this will add to the RGB Analog information database for all to use.

[rkgladney]

I am looking for a way to take a PS2slim and change the horiz sync from ~15khz to 31khz so it can be used with a standard lcd screen using a RGB signal.  If you stumble upon a trick that works I would be very interested.

[RARusk]

So far no luck with that.

But I just recently acquired a .pdf of the SCPH-70000 PlayStation 2 Service Manual I am just now starting to comb through. I still would like to get my hands on a SCPH-50000 PlayStation 2 Service Manual though.