I had read somewhere that it was possible to use a Gamegear as display for
building a portable NES. That's all the information I had so I tried to find
if it was really possible and how to do it.
I knew that a TV cartridge for the gamegear existed. I though, maybe the all
the cartridge does is apply the video signal from the tuner to the right
contact on the cartridge conector?
I found a file (ggpins.txt
) which identified
the contact #43 as 'TV cartridge signal'. Unfortunately, when I applied
a composite video signal to this contact, it did not work.
Since it was not so simple, I bought a TV cartridge on ebay. After looking
inside the cartridge, I think it approximately works like this:
- The cartridge pulls contact #43 to ground, taking control
of the LCD.
- The tuner sends the analogic video signal to a custom chip which
displays video on the LCD.
Bottom line, I dont think it's easy to modify a Gamegear to display a TV signal. I created
this webpage to inform poeple of my experiments and to allow them to have a look to the
TV cartridge circuitry without buying one.
Better buy a second hand TV cartridge or forget about using a Gamegear as display
since the image on a Gamegear is not very good:
Here's a page with more information about the TV cartridge: