While getting that Sega Channel related device dumped, I also got another oddball cartridge dumped. The cart is plain and only has a "Universal Driver Test Program" label on the front. It will run in emulators and on an Everdrive. The only screen moves a cursor with the d-pad while changing values on screen and also changes values when a button is pressed. As far as we could tell, it was used to demonstrate and test controllers and peripherals. The code even mentions the Activator and the Mega Mouse. http://s000.tinyupload.com/?file_id=94446150587518812349 There is another version of this ROM out there (Version 4.0), but given the earlier date and lack of version number on this one...it could possible be V1.0. If anyone has a concrete idea as to what this was for, I'd love to know. Otherwise, feel free to mess around with it!
It seems as if it's just a developer tool meant for quickly referencing joypad input and screen positions, and was likely used universally by Sega employees. I highly doubt there was any greater purpose than that. Matt Phillips (BigEvilCorporation) wrote something very similar, which can be found on GitHub. It should also be noted that, in this ROM, the VDP is set to run in H32 mode (a resolution setting that uses a width of 256 pixels - 32 tiles), rather than the commonly used H40 (320 pixels in width - 40 tiles).
Pretty cool tidbit on the VDP. I wasn't expecting some grail item, but always was curious as to what it's actual function and story were. Attempts elsewhere to figure out what this was got me the wise guy answer of "it's a universal driver test program." Also, images of the cart and such below. I'm not able to use the IMG tag yet, so will have to work with links for the time being. Cartridge Board