Hi sorry to bump and old thread.

I have an identical set of these and want to find out a bit for infomarion on them, they came from THQ and that's about all I know.

I also wouldn't mind knowing what they are worth.

Posted them here - THQ Dev carts for the GBA https://imgur.com/gallery/U4zDM

Thanks

Yeah, timbob's right

they've ended though, so even if I was planning on getting one, there's no chance now.

There are a bunch of pics in the eBay link, looks like there is a connector for a cable on there.

It looks like a GBA cartridge judging from how it says AGB (Nintendo's codename for GBA products.) The font on the sticker makes me think it's legit. Obviously, all the components (except the battery) are on the other side of the board. That's where the conenctor would have to be as well. However, this doesn't add. The board shape isn't routed so that it's narrower at the bottom, and there are vias through where the exposed copper would be on the other side.

However, the sticker gives a hint. The text says AGBサブカートリッジ 512Kフラッシュ. Or AGB sub cartridge 512k flash.

So it was probably meant to be used in a modular system, like the Intelligent Systems debugger.
http://devkits.handheldmuseum.com/IS-CGB-EMU/

If you could get a picture of the other side so you could see the connector for maybe a ribbon cable or something, that would be useful.

Weird thing is: I can't see any connections a cart has, like, where it connects with the gameboy...

So I'm guessing not normal dev carts...
Also: is says copyright 2000
that's way to late for normal gameboy stuff

Maybe N64?
or GBA? (it does say AGB in the code)

During my daily perusal of ebay, came across these;

Just wondering if anyone could shed any light on exactly what they are. I mean, they look legit enough, but I'm curious about their backstory more than anything else.