From: jtilton@vt.edu (Jay Tilton) Newsgroups: rec.games.video.classic Subject: DIY Masterplay Clone - 2600 stick on a 5200 Date: Mon, 1 Apr 1996 02:05:33 The latest incarnation of the Vandervort/Tilton Masterplay clone. *** 100% 2600 stick comatibility achieved *** Mark Vandervort (hy648@cleveland.Freenet.Edu) came up with a clever idea to allow you to connect a regular 2600 stick to a 5200. I massaged it a little to come up with what's presented here, but Mark's original idea was the inspiration. There's still a lot of the original in the current design. If you recall the last revision that I posted, there was a small incompatibility problem with a couple 2600 sticks. No more! Adding two diodes makes it 100% compatible! Works great with every stick I could drag out of the closet, including the 2600 remote control joysticks and my Gensis-to-7800 pad. I've been using it for some time now with dynamite results. Build one for yourself and try it out. You'll love it! If you can't get it to work, send me (Jay Tilton / jtilton@vt.edu) your questions. Materials needed * (2) 1 megohm potentiometer, Radio Shark #271-211 * (2) 1 kohm resistor, Radio Shark #271-1321 (includes 5) * (2) PNP 3906 transistor or similiar, Radio Shark #276-1604 (includes 15) * (2) 1N4001 diode, Radio Shark #276-1101 (includes 2) * (1) 9-position male D-sub connector, Radio Shark #276-1537 * Some way to connect to the 5200 controller port. Radio Shark doesn't have any 15-position female D-sub connectors, but it's come to my attention (thanks, Ted) that Best Electronics does. In a real pinch, you can take 25-pin connectors and cut them down with a hacksaw to 15-pins to make a Y-adapter that pipes the keypad/function key stuff (pins 1-8) to a regular controller, and the joystick-related stuff (pins 9-15) to this thing. * Tiny wires, and lots of them. * Beer, preferably something good. Real beer isn't trasparent. Real good beer isn't even translucent. Schematic 5200 port 2600 stick --------- ---------- pin 12 +5V------------------------pin 7 +5V ]Not entirely necessary ] unless you're using a ] rapid-fire stick/adapter. pin 15 Ground---------------------pin 8 Ground pin 13 Bottom Fire----------------pin 6 Fire pin 10 H-pot----------->|---------pin 4 East ] | 1N4001 ] | ] | 1M pot ]Duplicate all this |-----------\/\/\/-- ] for the vertical | ^ ] control circuit. | Pin 9 Pot_| ] Mentally substitute | Common ] the following pin | ] numbers: |______ ] Port pin 10-->11 \ 1 kohm ] Stick pin 3-->1 PNP \|___/\/\/\__pin 3 West ] Stick pin 4-->2 3906 ^| ] Pin 9 Pot__________/ ] Common ] Function * Pushing east on the stick shunts the horizontal circuit to ground, mimicking the effect of infinite resistance between pot common and H-pot. * Pushing west causes a short circuit between pot common and H-pot, i.e. zero resistance. * The potentiometers let you adjust the center position. Additionally, the potentiometer in the horizontal circuit can be used quite effectively as a paddle controller for games like Super Breakout. * The fire button works exactly like it does on the regular 5200 controller. Good Things * No more problems with games that were unplayable with your crummy non-centering 5200 sticks. * Cheap! Figure buying everything you need from Radio Shark, including a nice project case to stuff it all into, would cost less than eight dollars. * It should work with every 2600 joystick under the sun. I've tested it with my regular mechanical switch sticks, my Genesis-to-7800 pad, my NES-to-7800 pad, and my 2600 remote control sticks, and they all work peachy-keen. Bad Things * No second fire button. If you want, you can glue an extra fire button onto your 2600-compatible stick of choice. Just wire it up between port pins 14 and 15. * Won't work with games that require the analog capabilities of the 5200 stick, like Missile Command. A few other games like Centipede and Galaxian make limited use of the analog-osity of the regular stick by giving two movement speeds depending on how far you push the stick. With the adapter, you can only get the fastest speed. It's not a huge handicap, but it's probably worth mentioning. * Neither this adapter nor the Masterplay interface gets along well with three particular games: Qix, Vanguard, and Ms. Pac-Man. There could be others, but I only own a third of the released 5200 library. They will respond to pushing east (or south) on the stick as if you're pushing west (or north). No real clue exactly why this happens, but there is a way to work around it. Start up a game, slowly rotate the two potentiometers through their full range a few times while thrashing the stick around, recenter the potentiometers, then start a new game. Possible enhancements not yet implemented * 7800 stick compatibility (i.e. with two built-in fire buttons) * Genesis pad compatibility * Jaguar controller compatibility (Using the built-in keypad. Tricky.) * 2600 paddle compatibility * Selectable/adjustable rapid fire I've received a question wondering whether there are any plans to put this device into a limited-production run for sale to netters. If there's a large enough calling for it, I can certainly investigate the possibility. If it were to go into any sort of production, it would have to be a nicely done unit, meaning the tangle of wires would be replaced with a printed circuit board, the correct plugs and jacks, no-brainer plug-n-play operation, and a nice case. My personal vision of the final product would be functionally *identical* to the coveted Masterplay, except it wouldn't have the slide switch that lets you use the joystick fire button as the "start" button. (Pah! Who needs that bit of featurism?) A wild-ass-guestimate of the cost would be less than $20. Maybe it could be done for even less in kit form. If you're interested in this, drop me a line. I ain't promising it will happen any time soon, or that it will happen at all. I'm just looking to guage initial interest in such a thing before I invest my time in scoping it out. Skoal! -- Jay Tilton | jtilton@vt.edu | Virginia Tech http://fbox.vt.edu:10021/J/jtilton/index.html