What modchip do I have and what can it do?

General information to do with the PlayStation 1 Hardware. Including modchips, pinouts, rare or obscure development equipment, etc.
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provato
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What modchip do I have and what can it do?

Post by provato » May 7th, 2014, 4:40 am

Hi guys, and congrats on the PSIO, I'll surely buy one once it's out in matching grey ps1 casing :P
Although I would like to see a USB external drive solution, since I'm dumping for redump and have too many games on USB

I have an SCPH-7502 PAL playstation which has the following modchip attached (It's there since somewhere between 1998-2000):

Image

Image

Questions:

-What modchip is this? (multimode, old crow, onechip, stealth....)
-Does it need extra wiring (only 5 cables are connected, whereas it has 8 pins)
-Why do NTSC backup games play in black and white? Any way to fix this?
-Is there any way to access the chip's configuration options? (like in ps2, that I hold triangle+circle to access matrix infinity)
-Will it play anti-modchip US games?
-Do I need to patch libcrypt games to be able to play them?
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Post by LameGuy64 » May 7th, 2014, 7:30 am

- No one knows for sure unless you test it since all PS1 modchips use the same chip but with different code written in it.The only thing that you should be concerned of is whether it is a Stealth chip or not which can be tested by attempting to play an anti-modchip game (such as Spyro 3). If the game works normally, then you got a Stealth.

- The number of wires solely depends on the code programmed into the PIC... Its best not to bother about it if the chip is already in there.

- As for the NTSC color problem, you're going to need to perform a color fix mod here: http://www.psxdev.net/forum/viewtopic.php?f=47&t=444

- Nope, all PS1 modchips have no configuration menu since they're pretty much dumb PICs...

- If your modchip isn't a Stealth, then you're still going to need to patch anti-modchip or libcrypt enabled games to be able to play them properly.
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Post by provato » May 7th, 2014, 7:49 am

Thank you for your answers!!!

I'm really confused with the colour correction though...
On the modchip guide here in psxdev, I found a picture showing a different color fix (look at points "B" & "C"):

Image

Which is the right one?

EDIT: I connected the Playstation through simple SCART connector to a Sony Trinitron old TV, and now the NTSC games appear with colour!!!!! I wonder why though... What does that television make differently???
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Post by Tommy » May 7th, 2014, 9:25 am

provato wrote:EDIT: I connected the Playstation through simple SCART connector to a Sony Trinitron old TV, and now the NTSC games appear with colour!!!!! I wonder why though... What does that television make differently???
Your SCART is hopefully supplying an RGB signal. There is nothing inherently NTSC, PAL or SECAM about an RGB signal — those are just different ways of hiding colour information inside the black and white signal. Technically none of them mandate a frame rate even if we usually lazily use NTSC to mean 60Hz and PAL to mean 50Hz.

Also if your TV is from the mid-'90s or beyond it can probably just decode NTSC colour. There's not a huge difference between PAL and NTSC — NTSC was the original and PAL is the later improved version. If you're doing it digitally you can almost treat them the same and if you can almost treat them the same then you might as well build your electronics to do either, use the same chips everywhere in the world and pocket the economies of scale.

(unnecessary addendum: PAL builds on NTSC by adding analogue error correction. That's why NTSC sets needed tint controls and PAL sets didn't. PAL does this by constantly adjusting something that is specified afresh on every scan line. With analogue electronics you have your own idea of what the value should be and nudge it at the start of every scan line. Over a small amount of time the two things converge and colours are correct. But you can't just reset it because there's a momentum involved, and getting the wrong type of signal throws all that off balance. With digital electronics you can just box every scan line off and deal with them separately. Apart from that it's just clock rate differences. SECAM's a whole other story as the French decided not just to adapt and fix NTSC but to throw it out completely.)

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Post by Shendo » May 7th, 2014, 9:30 am

There are a few things to note regarding modchips and copy protected/mod detecting games.

Some (all?) modchip detection games also have an extra check to see if the code is ran on the American console.
So even if you have a basic "old crow" chip on a EU console, modchip detection games may still work properly.
Test with NTSC copy of Dino Crisis for example, works fine here on all chips I've tried.
Game is not patched (I checked MD5 hash against redump project).

Libcrypt is a copy protection based on the nonstandard subchannel data.
In that case modchip doesn't matter at all, it's the way you copy games which matters.
You must use a burning software which will read and copy subchannel data byte for byte and
not simply reconstruct it (by standard) as majority of the software does.
I recommend CloneCD game profile copying.

So chill, with a PAL fat console it almost doesn't matter what modchip you have.

As for the color problem, SCART uses dedicated lines for each R,G and B component that's why you get color.
Unlike composite which has a PAL or NTSC colorburst and latter is not supported by your TV.
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Post by provato » May 7th, 2014, 9:49 am

I don't think any of the above mentioned is what really happens with colour showing in Sony Trinitron with NTSC PSX games..
Let me explain:

1st I connect the scart (composite in scart adapter - official ps stuff) in my grundig CRT TV. No colour on NTSC games.

2nd I connect the scart in my Sony Trinitron TV and it shows colour on NTSC games!!

3rd I connect the composite cables (yellow, red, white) to "av3" of my Sony Trinitron TV, and it still shows colour on NTSC games.

Also another question comes to mind:
If all newer tvs (as mentoioned) can show colour on NTSC content, then why should anyone perform the colour fix on modded Playstation?

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Post by Tommy » May 7th, 2014, 10:04 am

provato wrote:I don't think any of the above mentioned is what really happens with colour showing in Sony Trinitron with NTSC PSX games..
Let me explain:

1st I connect the scart (composite in scart adapter - official ps stuff) in my grundig CRT TV. No colour on NTSC games.

2nd I connect the scart in my Sony Trinitron TV and it shows colour on NTSC games!!
SCART carries composite, s-video (chrominance and luminance separately — two signals) and RGB. That's partly why it has so many pins. Your Grundig isn't necessarily using the RGB signal.
provato wrote:3rd I connect the composite cables (yellow, red, white) to "av3" of my Sony Trinitron TV, and it still shows colour on NTSC games.
Then it can clearly also decode NTSC colour. Which means it also may not be using the RGB signal. But it doesn't make much odds.

On the negative side, if it's a Trinitron then you'll almost certainly actually get black lines in between actual scan lines on non-interlaced games because it's an aperture grille rather than a shadow mask. But the colours should otherwise be better.
provato wrote:Also another question comes to mind:
If all newer tvs (as mentoioned) can show colour on NTSC content, then why should anyone perform the colour fix on modded Playstation?
I would assume there are plenty that can't. There were colour televisions for, what, about 50 years before the analogue ports vanished? It'll only be the final ten or fifteen or so in which all sets were both NTSC and PAL capable. A Trinitron is an expensive set so it probably had the feature a lot earlier than the market average.

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Post by provato » May 7th, 2014, 10:14 am

Thanks for the info tommy. I suspected that Trinitron was "NTSC-capable".
As for scart, I surely have to read more about its pins. Once I had a dvb-t decoder connected to a Thomson TV, and whenever I switched off the device, the TV would also turn off!!! Later I read in wiki that scart has a pin for on/off function signaling to TV! But only Thomson used this feature..

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Post by Shadow » May 7th, 2014, 3:25 pm

provato wrote:Thank you for your answers!!!

I'm really confused with the colour correction though...
On the modchip guide here in psxdev, I found a picture showing a different color fix (look at points "B" & "C"):

Image

Which is the right one?
They are both the same.
Your modchip looks like a MM3.
Development Console: SCPH-5502 with 8MB RAM, MM3 Modchip, PAL 60 Colour Modification (for NTSC), PSIO Switch Board, DB-9 breakout headers for both RGB and Serial output and an Xplorer with CAETLA 0.34.

PlayStation Development PC: Windows 98 SE, Pentium 3 at 400MHz, 128MB SDRAM, DTL-H2000, DTL-H2010, DTL-H201A, DTL-S2020 (with 4GB SCSI-2 HDD), 21" Sony G420, CD-R burner, 3.25" and 5.25" Floppy Diskette Drives, ZIP 100 Diskette Drive and an IBM Model M keyboard.

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