Actually, you don't even have to open the 7800 up. Slip a box knife down into the sleeve right below the cart port, and slice upward. That should let the sleeve expand far enough to accomodate most any game (except maybe Tigervision).
I went a little more in depth--I actually removed the sleeve from the board and cut out the bottom corners. On my 7800, you wouldn't notice that the sleeve has been cut at all unless you looked, and if you did see it, you'd think it was manufactured that way. If I'd had a Tigervision cart at the time, I'd have cut out for those as well.
Remember, I sliced a mint 7800 shortly after I got it.
Your pass through cart would be ideal for heavy sixer owners, though. If it fits one of those, you might have a market for them in the 2600 forum.
As for the 7800, though, the pass through cart is just a stop gap measure for backwards compatibility. Soon you're going to want the TV Type switch for games that use it as further difficulty setting, and you're going to want to pull the timing circuit (if it has one). You may also want A/V jacks, which will require three holes (chroma, luma, and audio) to be mad ein the case, or four holes if you want stereo output from the TIA or a dual POKEY XBoarD setup.
Finally you'll want a new power jack when the brick you have dies. Actually, that'll probably be the first thing you change, since those wires on the brick aren't getting any newer.
I really wish you guys could look at my 7800. Pictures don't do it justice. The only other system I have that's so pristine is my box PS2, and I've modded that a little bit, too. I've got no problems adding stuff to either one, as long as it's done immaculately.
Edited by shadow460, Thu Jan 11, 2007 10:09 PM.