Info Needed: Sega Genesis Test Cartridge

[Penguin]

Hey everyone, was looking for some info on a test cartridge my buddy and I found. We have quite a bit of Nintendo test equipment but have never come across something like this. It was a black blank sega genesis cartridge with a label that says Test Cartridge on it. Booted it up and it says "Get Ready" and plays a sound sample, along with the color screen and a simple test program for the controllers. Was wondering if any of you guys have any info on this, as we can't find any mention of this test cartridge anywhere. Thanks.
http://nintendoagemedia.com/users/219/photobucket/861B39FA-B93A-55BA-3809FFCEC0946B44.png
http://nintendoagemedia.com/users/219/photobucket/861D9F85-0988-2026-A5AFFC1B817CA832.png
http://nintendoagemedia.com/users/219/photobucket/862020C6-0282-B695-CFE641A5CFA7ABE6.png

[Penguin]

Bump, still looking for info on this!

[Deadman]

I have nothing to add here except that it is awesome and I'm jealous that I don't have one of those! Love weird, wacky gems in the collection! :)

[xelement5x]

Interesting that it also looks for input off the EXT port.

[bust3dstr8]

Looks like something a tech at a Sega repair center would of made to help fix consoles.
Someone with some 68K assembly knowledge could of made it in a short time.
The dev pcb is Sega issued and uses 8bit eproms, which would of been much cheaper than
the 16bit ones back in the late 80's.
The actual dev pcb is somewhat common, I think it was the Nolan Bros. that where selling off hundreds of
them at $12 a pop a few years ago.

So considering this is mostly likely just a quick homebrew debug cart made in the back of some shop, I would
say it's worth about $30