Super Gameboy link port

I am looking to add a link port to the Super Game Boy (As well as the under clocking hack to fix it) however the information I'm finding for the link add-on is seemingly users choice and being relatively new to modifications and soldering I would like to know I'm on the right path before I try it, it doesn't work and it is process the whole time instead of my abilities.

Long and short of it, I've seen 4 different plans/boards for it and the only bit of information that seems to be standard across is the need for 220ohm resistors on the sgb pins 68-70 to their respective pins.

Beyond that I am seeing schematics with 0 up to 7 diodes and I am a little unsure about what exactly is needed. Here are links to the information I found.

http://store.thursdaycustoms.com/product/sgb-link (prebuilt - Looks like 3 resistors no diode)
http://farm5.static.flickr.com/4066/...d4b809760c.jpg (Original JP schematic, 3 resistors 1 diode)
http://www.mksmks.de/technical/sgblink_05.gif (3 double diode, 3 resistors)
http://www.devrs.com/gb/files/sgbmod.txt (7 diodes, 3 resistors)


Now, I have recently finished the NESRGB install so I'd like to continue by actually creating the circuit and installing as opposed to buying the thursday customs option. So has anyone else worked with this before and if so what is the ideal setup?

-Nilats

The diodes are a protection circuit, to protect against static electricity and any other source of overvoltage.
You should include them (all six)

Okay so, I know about 3 things about diodes...

I am putting together parts lists off digikey and it seems to me that the type/specs of diodes only matter on projects where you are using higher currents and can burn them out (is this incorrect assessment?)

So for this project would something like http://www.digikey.com/product-search/e ... vendor=261

Have you ever heard of the Super Gameboy 2? it's essentially what you are trying to make and it's pretty cheap on eBay. Unfortunately, It only works on the Super Famicom, but I am sure you could just carve out some of the plastic on the cartridge to play it on an American SNES.

Here's a schematic of the original gameboy If you look in the top-right where there are 4 identical circuits with a 220ohm resistor, 100pF capacitor, and a pair of diodes, that's what you'll want to recreate. The schematic doesn't specify, but you want 5V reverse voltage. Here's a Digi-Key part that contains a pair of diodes in a single package, so you'd only need 4 of them: http://www.digikey.com/product-detail/e ... ND/2425046

Yes, I've heard of it but I am working on a series of projects and I'd rather not destroy a 30$ sgb2 when I can destroy a 10$ sgb and few bucks in components.




Okay, that looks good I appreciate the help. I started working with basic soldering and all this just a few weeks ago. I am making strides but it is slow going.

Don't trash the cart, cut the tabs out of the cart slot on the console itself. Press down the cover flap on the cart slot and you should see two plastic tabs, just cut them out and it should work (assuming you have a US SNES, I don't think PAL SNES's can play JAP imports).

No, no I mean I'm destroying the SGB which is why I don't want to use the SGB2. I am using old/broken copies of GB games (took copy of pokemon gold that had rusted connections) and wiring them directly to the board making custom SNES carts. Hence why I don't want to use the SGB2 at the higher price as the base hardware.

I don't see the motivation behind this, so I'll just suggest something else. Rather than doing what you're doing, why not de-solder the mask ROMs from "broken" valuable Game Boy titles like Pokemon and put them onto working boards with matching mapper/SRAM configurations from cheaper titles?

This is a project for my personal collection, it isn't about selling the games back or trying to turn a profit.