13 07 2017
Reverse Engineering the Playstation G-CON 45
I’ve recently been interested in my old Playstation 2.
Having played with the Playstation 2 when I was younger I remember the fun my brother and I had playing Time Crisis 3 with the G-CON 2 and the G-CON 45.
Now, most (all?) older version light guns don’t work on the newer flat screen TVs.
This is because of how they process / display the frames.
I researched how the G-CON45 works and it uses what’s known as the cathode ray timing method.
To my understanding, every H-SYNC increases the Y-coordinate by 1. The X position is determined by the timing between two H-SYNC and when the sensor sees the change in brightness of the “pixel” on a CRT TV, due to the electron beam hitting the phosphor.
Then it’s just a matter of passing on those coordinates to the Playstation and a bit of collision detection to determine if you hit a “bad guy” or not.
After a bit of research on google, I couldn’t find any claims that approved or disapproved my understanding of the G-CON 45.
So I did what I usually do, crack it open, see what’s inside and google again.
Here’s the PCB reverse engineered. It’s a small board and didn’t take too long to make.
The capacitor values might be wrong, I’m using one of those €20 component tester.
In PDF format : G-CON 45 schematic pdf
The PCB has 2 ICs, one sensor, one crystal oscillator and a bunch of resistors and capacitors.
Googling the main CPU or DSP NAMCO103P resulted in one website.
This one : http://problemkaputt.de/psx-spx.htm
The website is a goldmine of information, it has everything I needed to know, mainly that the G-CON 45 sends an X and Y coordinate to the Playstation.
But it also has the controller connector pinout, explanation and ASCII drawings of the communication protocols, and tons more ! Although it’s a website for the PSX, it helps a lot to know all these things.
I’ve contacted the owner of the website (Martin) and he has been answering all my questions via e-mail. It’s pretty cool of him to take the time to respond !
Knowing that the G-CON 45 send an X-Y coordinate to the Playstation.
What if you could roll your own electronics which sends the coordinate to the Playstation ?
What if you could take, let’s say, the camera inside a Wii remote and use that as the G-CON sensor ?
The Wii remote works on every TV, so if we could use that for the G-CON 45, we wouldn’t need a CRT TV to play games like Time Crisis.
As of now, I know the Wii camera is a PAC7010 by a company named PixArt Imaging Inc. I’ve e-mailed them to see if they would sell some to me.
Here’s a website that has a lot of information about the Wii remote, linked is the IR camera : http://wiibrew.org/wiki/Wiimote#IR_Camera
Anyways, the next step will be to mess around with the Wii remote camera.
I’ve purchased fake Wii remotes (~€7) and will be buying a real Wii remote (~37€).
I’ll compare both real and fake remotes and decide what I’ll do from there.