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Playstation scph-7502 (PU-22 PCB) modchip question and modchip diagrams request

provato

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Hi everyone, I know I'm a bit late in 2019, but I decided to clean up and modernize my PAL video game consoles recently, including the original playstation.
First of all I would like to know what modchip is installed in my system, if anyone can recognize it from the pictures below
(I suspect it is an oldcrow since it uses five wires on 4 IC legs - 1,5,6 and 8)
thumbnail_IMG_6962.jpgthumbnail_IMG_6963.jpg
Second question is about old modchips and anti-modchip ntsc-u and ntsc-j games. I've read somewhere that PAL region consoles equiped with old modchips can run anti-modchip backup games without problems. Is it true?
I'd like to know if it is necessary to replace the current modchip with a modern stealth one, in order to play ant-modchip games. Unfortunately I do not own an anti-modchip game to make a backup yet.
Last but not least, I'm trying to find a source of wiring diagrams, alternative soldering points etc guide for the playstation modchips, but all online such sources seem to be deleted. I'd like to keep a folder with information about all modchips for the ps1 over the years - from oldcrow to mm3 and mayumi 4.
Does anyone have or know where to download such a source?
Thank you

PS: I was able to play a back-up ntsc-us CD of resident evil survivor which is known for its antimodchip protection. So I'm guessing this is because I am playing it on a PAL console? I will try a japanese antimodhip game if I can find a disc to back up.
 

provato

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Wow this is a great collection, can’t wait to study it. Thank you for sharing!!
Anyway I removed the chip and I will dump it next week, then I’ll post the code here if anyone wants or knows it.
Meanwhile I tested a few anti modchip games (jap and us) and they all work in my modded pal 7502 ps1!!
Libcrypt of course needs ppf patching or clone-cd dao/sao writing.
 

Trimesh

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That does appear to be an "old crow" type chip, with the 4 wire + link wiring that was common before the chips that were specifically designed for the PU-22 were released. It works OK, but can somewhat degrade tracking, especially if the optical pickup is old and tired.

And yes, most anti-mod titles will boot correctly on PAL systems even if using a non-stealth mod chip. The exceptions are certain early anti-mod games (like the NTSC:J version of Dino Crisis) that don't include the logic to disable themselves when run on a PAL system.
 

provato

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What do you mean by “degrade tracking”?
Is my optical pickup in danger with this chip?
What modchips are specifically for pu-22?
Omg so many questions! :p
 

provato

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Ok I dumped the contents of the 12C508A chip today, here is the .hex and .bin file:
Code:
.BIN:  https://mega.nz/#!wtNR0ALa!kSOEnODcUw8CK0o8KD9uCygsRqyK5T-M3KvZBwUZuFs
.HEX:  https://mega.nz/#!oxETjQiJ!v_u6-ML1KBNj8UmrC3euX3Y8EJ9g2T-BSDRUdmTtIoM
it seems to bare a resemblance to oldcrow v1.01 MODC508.HEX file.
I read the corresponding MODC508.ASM file and I don't have a clue what it's talking about

Anyone interested enough to find which exact modchip version I have?
Once again, thank you
 

Mord.Fustang

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I ran yours and the MODC508 through a disassembler (PICDisam.exe) and they're almost identical but I couldn't tell you the difference with them at quick glance. Either way, it's safe to say it is the same or a *slightly* different revision.

If you are decent at soldering and have a programmer to make a new chip, it's probably best to upgrade.

If you don't have access to that, the current install is probably fine as well. Don't lose sleep over it.

If you obtain your games from... "unofficial" sources, most anti-mod games are probably already pre-patched anyways.
 

provato

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Thank you, I am just starting at programming, so I didn't know the connection between hex and asm :p
It's not about soldering skills, I can do any mod and I usually make improvements to existing mods.
I never needed to do anything to the ps1 up until now, simply because it plays any back-up I throw on it except from libcrypt.
It's about what is better for: 1)compatibility & 2)console long-lasting
I will probably buy a psio also, so disc-playing will be minimized. But I wouldn't want the optical pickup to die in a few years. I recently cleaned and regreased the mech, it's the original one from 1996.
 

Trimesh

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What do you mean by “degrade tracking”?
Is my optical pickup in danger with this chip?
What modchips are specifically for pu-22?
Omg so many questions! :p
On the earlier boards (PU-7 to PU-20), the signal used for the copy protection was picked off just after the optical pickup, processed and then fed into the mechacon CPU as a digital signal. Since it was a completely different signal path, it didn't affect the way the CD player worked at all.

On the later boards (PU-22, PU-23, PSone), most of the CD circuits have been collapsed into a single chip and the wobble processing is in there too - they also removed the physical connection that carries the signal to the mechancon CPU and replaced it with a data stream that was carried on the same wires used to communicate the "Q" subcode from the CD DSP to the mechacon. The overall effects of these changes is that the only remaining option is to inject the modchip data directly into the tracking error signal and rely on the filters in the tracking servo to get rid of it. This is why these later chips use the WFCK signal for gating - it's high enough frequency to fall outside the passband of the tracking servo while being detectable by the wobble detection circuit.

The problem is that this approach only lets the actual tracking error signal through 50% of the time, since the other 50% the pin is being used to send simulated wobble data. This effectively reduces the overall gain of the tracking servo by 3dB - under normal circumstances, the servo has more than enough gain margin to handle this without any adverse effects, but can start to cause problems when for some reason (like a weak laser) the overall gain margin is degraded.

Since the specific chip you are using doesn't have the internal gating for WFCK (the design predates the release of the PU-22) , it was connected using a wire link and then shorted out using the open drain output on the PIC. This is in theory an inferior approach, but in practice it seems to work pretty much as well as any other chip on these boards.

The chip that interferes with tracking the least is the latest version of PsNee - that entirely disable the outputs when it's not injecting data, so once the initial authentication check is passed should have no effect at all. It does still incur that 3dB gain penalty when active - but since the media checks are carried out when the disc is running at x1 speed where it has a lot more gain margin anyway this shouldn't cause any problems.
 

provato

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Thank you for this valueable info Trimesh, I'll definitely check out your other posts in here to learn more.
I have also confirmed that dino crisis (usa and japan) do not work with my modchip (I get the japanese anti-modchip screen).
Nevertheless I decided to keep the existing mod for nostalgic reasons and maybe upgrade to mayumi later. That's also why I mounted the chip on a vero board.
IMG_6964.JPG

PS: Can someone point me at or share the latest mayumi hex/bin for the pu-22 board?
 
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provato

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Waiting for the pic12f508 ICs to arrive from China (in order to upgrade to mayumi v4), and I thought I'd see if I can find an alternative solder point for #4 cable, closer to the modchip loacation on board.
Here is the original picture that shows all the solder points for my pcb (pu-22):
PU22L.jpg
I was surprised to find so many vias and solder pads for point #4 so much closer to the other solder points, by following the traces on board!
In fact, there is an obvious solder pad for the reset button connection (point #4) right next to point #7!!
As you see in the picture, original point #4 and the smaller solder pad next to point #7 show continuity in my DMM:
IMG_7039.JPG
This brings up the question: hasn't anyone ever thought about finding a closer solder point #4, or maybe for some reason, that I am not aware of, attaching a wire closer to the others will not work?

...anyway I'm going to test the reset button function of the mayumi v4 code when the ICs arrive and I install one on my ps1.
Here is a corrected install guide-picture for anyone that wants to try the new solder point #4:
PU22Lnew.jpg

One more question about pic12f508 programming:
How do I disable "code protect" in order to be able to verify the chip after programming it?
I'm using a GQ-4x4 programmer from MCUmall
Thanks!
 
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Nully

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Yes, just that no one cares enough to redo the diagrams. It's all memory for me having done these so many times over the years I've never felt the need to write it down, but it's been a very long time since I used the "officials" and I'm be surprised if anyone who does this more than a few times hasn't found easier and quicker ways.

If you want to make your own then that would be awesome, anything new to the "scene" is appreciated.
 
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