 |
Table of Contents Procurement
Time to go shopping. The two biggest components are one or more SNES controllers and a cheap keyboard, neither of which you should have any reservations about scrapping. I bought one new SNES controller off of eBay. It appears to be after-market (a.k.a. cheap knock-off). It's got the "Super Nintendo Entertainment System" text on it and the same colors and button labels, but it's seems a little shoddier than the ones that came with my system (I didn't want to trash my own controllers for this project). The keyboard I got from Radio Shack. Don't get anything fancy. Really. Internet buttons, trackpads, etc. are all going in the trash, so save yourself some money. Make sure the plug is right (PS/2 probably) and that the scroll lock, num lock, and caps lock LEDs are in the upper right corner, not on the keys themselves or anywhere exotic. If the lights are in the corner it means all the guts are on one small IC board, not spread all over the keyboard. Extraneous lights or other electronica not located in the upper right are bad signs. Get the simplest, cheapest, no-frills keyboard you can find. Your best bet in this area (and for expense) is to find a keyboard at a used computer store or auction. Take the keyboard home and make sure it works. After you've satisfied yourself that it's not a lemon, open it up and take a look inside. Don't be afraid, there's little in there that you can destroy without being pretty purposeful about it. Always remember about electronics: if the people on the assembly line couldn't break it, then you probably can't break it either. Just don't drop things on concrete or stick it into a wall outlet and you'll be fine. The thing you're looking for is the circuit board, which resides in the upper right corner of the keyboard (where the caps, scroll, and num lock lights are). The usual layout consists of two plastic sheets with circuitry imprinted on them connected to the IC board, which is about the size of a credit card or smaller with three LEDs on it. Ideally, the plastic sheets should be attached in some temporary fashion, like inserted into a little slot. Try wiggling them free from the board. Again, don't worry about it. You're not doing anything irreparable. Just don't yank on any soldered connections. Also, it's nice if the keyboard cord is attached in some removable way. This makes working on things a little easier since you won't have to drag the cord everywhere. If you're able to completely remove the IC board without anything else connected to it, you picked a good keyboard. The keyboard cord may have a wire with an eyelet attached to a large metal plate or something. That's the ground wire. Go ahead and detach it. Now that you're familiar with the insides of your keyboard it's time to do the rest of your shopping. The first thing you'll need is a project case. Radio Shack sells these (and pretty much everything else I'll discuss here). It's simply a plastic or metal box with screws and possibly other hardware for containing the mess you're about to make. I'd recommend plastic to avoid unintentional shorts and make cutting easier, but if you're confident go ahead and get a metal one. You'll also need some 15-pin D-type connectors (not the 9-pin ones). These look just like the connectors on a CRT monitor (not flat panels, they use a different kind). Get one female and one male connector for each controller you plan on having. That reminds me, you need to decide how many controllers you want to support. I would recommend no more than 2, however you can create up to 4 if you want. I only made one because I was getting tired of soldering, but 2 is a respectible number and good for people who actually have friends. The reason too many controllers may be bad is, have you ever mashed down a dozen or more keys on your keyboard at once? And the computer beeps at you and doesn't really type any characters? Yeah. There's some sort of limit preventing too many keys from being pressed at once. If you make four controllers and you and your buddies are all smooshing down 3 or 4 keys at once it may act unpredictably. Likewise, you're just making a lot more work for yourself, possibly without very good results. If anyone succeeds in building a four-port controller I'd love to hear about it. OK, back to our shopping cart. In addition to the D connectors you'll need plug housings for them, one per controller. This is a small plastic cover that holds the D connector and allows a cable to come out the back. They usually screw together. Do a sanity check and make sure it looks like it would hold a D connector. Ask an employee for help if you're not sure. Who knows, they might even be able to answer your question! You'll also need some audio cable and some winding wire. We need the audio cable solely for its vinyl sheathing, not the wires inside. The cable should be a little more than 1/8" in diameter, but no bigger than the SNES controller cable, because that's what we're using this for. The winding wire is a very thin, insulated wire used for winding electric motors and electromagnets, but we'll use these for our button connections. We have to run at least 14 of those wires through the audio cable sheathing, so they have to be small. |
