I just picked this up today at the Swap Meet. At first I thought this would allow a regular PC joystick to work with the Playstation. The odd thing is the 15 pin 3 row layout looks like it would take a Jaguar Controller plug. PC and 5200 joysticks are 15 pin and two row. This is strange as an adaptor considering how few Jaguars were sold compared to other consoles with more available controllers. Maybe a Home built, however the labeling and cutouts are professionally done. There is a PCB inside to convert the signal and the PSX cable looks to be a black PS2 cable. not a grey PS1 type.
Its very strange. There are tons of adaptors to allow the PSX controller to work on various consoles as well as the PC. I have never seen another brand controller to be adapted to work on the Playstation though. The only controller with the right out of the box pinout connector seems to be of all things the Jaguar Controller. BUT THE PINS ARE MALE, JUST LIKE THE MYSTERY BOX. Jaguar seems like an unlikely candidate because of not very common compared to the other Ataris, Nintendo, Sega or even the XBox. Because the box looks commercial with possibly a PS2 cord, then maybe there is a rare peripheral that attaches to this.
Evidently the device that plugs into this doesn't have a Start or Select button that could be mapped, its already on the box. The Start and Select buttons are placed backwards on the box compared to a normal PSX controller.
I don't have a Jaguar controller to test this with. I do have some spare PSX consoles, I'm willing to take a chance of testing this on though.
I just pulled a pic of the Jaguar Console. The Jaguar ports are female, my mystery box has a male port with pins showing. So a Jaguar controller won't directly plug in without a double female adapter. The Jaguar console doesn't have controller pins showing. This is opposite compare to the 2600, 5200 and the weird adapter.
Can someone post a pic of a Jaguar Controller cable plug that shows the pins?
Made by CYPHER GAMES, anyone every hear of this?
EDIT
Looks like it might be part of a Dance Pad.
http://www.atariage.com/forums/topic/178299-cypher-games-psx-controller-adaptor-jaguar/
A shame there was no metal Dance pad at the Swap Meet that goes with this odd adaptor. But this allows an easy to add multiple custom digital controllers through that plug in port. Well just the arrows or movement only though.