Ya`no. If you were to connect A16-18 to some selector switches, you would have a multi-cart.

Also, verified your pinout as correct, and updated the post above.

In the photo of my current cart you can see the Red wires connected to pins 41 & 42 of the cart edge. These I have connected to a jumper on the outside of the cartridge enclosure.
When these two contacts are bridged or unbridged determines if the GameGear is in a SMS or GameGear mode. There are a few Cartridge adapters for the GG that allow you to use SMS cartridges.
So one could also use this flash cart to play SMS Roms.

All the more motivation to get this puppy running

-Gerry

Here is my latest updated GameGear ROM Pinout & Cart Edge Connections Diagram.



I'm hoping to get something working soon. Well see how it goes.

If anyone else is attempting a prototype GG Flash cart keep me posted.

We Will Prevail.


Later Folks,
-Gerry

Well; if the goal is to use SMS, then I guess that I will need to finish docs.google.com2010.09.20.wip.zip (edit) Eagle 5 libary containing descriptoins for Sega paging/mapper chips, Game Gear card edge, and 0.6"wide 0.070"pitch 42pin IC.
docs.google.com2010.09.21.wip.pdf
docs.google.com2010.09.20.wip.zip
megaupload.com2010.09.20.wip.zip


Could you verify if I have the card edge correct?

Edit: google docs suddeny decided that I had uploaded the zip file after a few mintues.

Holy Crap!...........This Eagle LBR you've compiled is Sweet!!

Way to go on the ZIP45 design. This will be very useful.

Let us all move our future discussions over to the new Topic I've opened up for this project:

Topic "SEGA GameGear Flash Cart - Custom Electronics"


See you in there.
-Gerry

Just fixed the bad Youtube video link.
Recently re-recorded the audio for these Instructional videos.

Cheers!
-Gerry