[This post is from 1995 so certain timely elements have been omitted such as emails and ordering information] --------------------------- This post including schematics is copyright 1995 by Brian Holscher. This information is free for distribution as long as its not used for commercial purposes. Using Sega Genesis Controllers with Vectrex (Revision 3.1) This Posting explains: 1. How to convert a Sega Genesis Controller to work with Vectrex. 2. How to make a Sega Genesis Controller to Vectrex Adaptor. BACKGROUND ========== Since my Vectrex controller is flaky, I bought a cheap Sega Controller and converted it to work on the Vectrex. From there I added some nice features like autofire and re-programmable buttons. I decided to post schematics for those who want to make Vectrex controllers. After talking with others on the net, I decided to build a Sega to Vectrex adapter. This is a little harder than converting controllers, but I got one to work. This posting includes info and schematics for both. For those who don't want the hassle of making your own controllers, I'm offering converted controllers and adapters for sale. I'm also offering a preprogrammed micro-controller for sale. LIMITATIONS =========== The Sega Genesis Controller is a digital controller. The Vectrex joystick is an analog controller. Games like Minestorm don't look at the analog values of the joystick and only look to see what direction the joystick is moved. Games like Minestorm work with these converted Sega Genesis Controllers. Games like HyperChase look at how far the joystick moves in a direction and are not fun to play with these converted controllers. All (known) games work with these converted controllers and adaptors with 2 exceptions. Hyperchase (all game variations) and Starhawk (game variation #2 only) are completely unplayable due to the need for analog controller data. Thanks to Gregg Woodcock for this info. FEATURES ======== This design incorporates a micro-controller for additional functionality. The micro-controller allows the user to program which Sega Controller button maps to which Vectrex button. This is useful since the 4th button (called Start) on the Sega Genesis Controller is a smaller and inconveniently located since it is normally reserved for starting games on Sega systems. The micro-controller even allows reprogramming of the button assignments in the middle of a game. Another feature is auto-fire. Any button can be set to auto-fire. This means that the micro-controller presses the button over and over again instead of the player. CONTROLLERS VS ADAPTERS ======================= Adapters give you the advantage of using any Sega Genesis Controller with Vectrex and still be able to use it on the Sega system. If you don't have a Sega Genesis Controller, a converted controller is less cost than an adaptor plus the cost of a Sega Genesis Controller. Another slight advantage is that the LED thats informs the user during button reprogramming and auto-fire is easier to see on a converted controller. The micro-controller is optional if you are converting your own Sega Genesis Controller. However, the micro-controller is required for the adapter. DOING IT YOURSELF ================= First the Disclaimer. I am not responsible for: 1. Any damage done to your Vectrex. 2. Any damage done to the Sega Genesis Controller. 3. Any errors in these instructions. I'm not going to give step by step instructions. I'm going to assume that the reader has some basic knowledge of electronics and can figure out what to do with the schematics and info presented here. I will, however, answer questions if asked. Now that I covered my backside, here is how to do it yourself: Converting a Sega Genesis Controller: ===================================== The micro-controller is optional. If you don't care about button re-programmability or auto-fire, then just connect the button to the connector pins as shown. Parts List: 1 PIC16C54-LP Microcontroller - Optional 1 32.768 Khz Crystal - Optional 2 15pf Capacitor - Optional 4 3.3K Resistor 4 10K Resistor 1 470 Resistor - Optional Schematic: ========== Direction Control: +5V (Pin 7) ^ | 10K .__|__/\/\/\/\___. | | Right Button -| 3.3K | | ._____/\/\/\/\___| | | |-------- X Direction 3.3K | (Pin 5) ._____/\/\/\/\___| | | Left Button -| | | ._____/\/\/\/\___| | 10K | -5V (Pin 9) +5V (Pin 7) ^ | 10K .__|__/\/\/\/\___. | | Up Button -| 3.3K | | ._____/\/\/\/\___| | | |-------- Y Direction 3.3K | (Pin 6) ._____/\/\/\/\___| | | Down Button -| | | ._____/\/\/\/\___| | 10K | -5V (Pin 9) Button Schematic if not using microcontroller Same for Button B,C, and Start except: Button B -> Pin 3 .__________ (Pin 2) Button C -> Pin 4 | Button Start -> Pin 1 Button A -| | .___ | | GND (Pin 8) Button Schematic if using a microcontroller. 5V (Pin 7) ^ | > Same for Button B,C, and Start > 47K except: > Button B -> PIC 12 .__|_______ (Pic 13) Button C -> PIC 11 | Button Start -> PIC 10 Button A -| | .___ 47K not critical. | Anything from 1K to 100K | should work. The controller GND (Pin 8) should already have something connected. Micro-controller Option: +5V (Pin 7) ^ _______ | 15 pF 16 | | 14 |---------| |---||---------|-----| |-----| | | Xtal | | | | 4 | < | 32.768 kHz | | | |-----| < 470 Ohms | | | 15 | | < |---||---------|-----| P | 1 | | 15 pF | I |--------|<-----| | 5 | C | LED |--------------------| 1 | GND (Pin 8) | 6 | 13 | C | 6 from Button A ---------| 5 |----- Pin 1 12 | 4 | 7 from Button B ---------| - |----- Pin 2 11 | L | 8 from Button C ---------| P |----- Pin 3 10 | | 9 from Button Start -----| |----- Pin 4 |_______| Notes: 1. Pins listed are those of the 9 pin connector. 2. I personally used a controller made by QuickShot since it was only $12.87 at K-mart. I've seen ones made by Sega for about $15. Depending upon which brand and type, the might be minor differences between these instructions and your controller. 3. On the Sega circuit board, you will need to remove the IC, pull-up resistors for directions. If you are not using a microcontroller, remove the pull-up resistors for the buttons. Otherwise leave the pull-up resistors for the buttons. 4. Normally, pressing the direction pad on a Sega Genesis Controller grounds that direction input. You will need to cut traces on the Sega circuit board to isolate the UP and RIGHT ground from the the LEFT and DOWN ground. You will also need to isolate these two grounds from the button ground. This is because instead of grounding UP and RIGHT, you will need to connect it to 5V. Also, instead of grounding LEFT and DOWN, you will need to connect it to -5V. 5. Thanks to David Vanderbyl for his suggestion of using 3.3K resistors instead of a pots. MAKING AN ADAPTOR ================= An adaptor allows a Sega Genesis Controller to be used without modification with the Vectrex. A micro-controller is used to decode the output of the Sega Genesis Controller. Sega multiplexes LEFT, RIGHT, and the buttons on only 4 lines. Since the Vectrex needs negative voltage for Left and Down, two Optoisolators are used to switch the negative voltage. Parts List: 1 PIC16C54-LP Microcontroller 2 NTE3084 Photo-Darlington Optoisolator 2 3906 PNP Transistor 1 32.768 Khz Crystal 6 1K Resistor 2 2.2K Resistor 4 10K Resistor 1 470 Resistor 2 15pf Capacitor 1 9 pin Male Subminiature D connector 1 9 pin Female Subminiature D Connector Schematic: Direction Control: +5V (Vectrex 7) ^ | 10K __|___/\/\/\/\___. 1K | / | Right from PIC __/\/\/\/\___|V PNP | |\ 3906 2.2K | |______/\/\/\/\___| | +5V | ^ | | |------- X Direction < 1K | (Vectrex 5) < 1K | < 1 ._______. 5 ._/\/\/\/\___| |___| |___| | | NTE | | Left from PIC _________| 3084 |___. 10K | 2 |_______| 4 |__/\/\/\/\__| | | | -5V (Vectrex 9) +5V (Vectrex 7) ^ | 10K __|___/\/\/\/\___. 1K | / | Up from Sega ___/\/\/\/\___|V PNP | (Sega 1) |\ 3906 2.2K | |______/\/\/\/\___| | +5V | ^ | | |------- Y Direction < 1K | (Vectrex 6) < 1K | < 1 ._______. 5 ._/\/\/\/\___| |___| |___| | | NTE | | Down from Sega ________| 3084 |___. 10K | (Sega 2) 2 |_______| 4 |__/\/\/\/\__| | | | +5V -5V (Vectrex 9) ^ | Sega 5 ___| Sega 8 ___ Gnd Micro-controller: +5V (Vectrex 7) ^ _______ | 15 pF 16 | | 14 |---------| |---||---------|-----| |-----| | | Xtal | | | | 4 | < | 32.768 kHz | | | |-----| < 470 Ohms | | | 15 | | < |---||---------|-----| | 18 | | 15 pF | |--------|<-----| | 5 | P | LED |--------------------| I | 1 GND (Vectrex 8) | C |------- Left Output | 1 | Sega 17 | 6 | 2 Select -------| C |------- Right Output (Sega 7) | 5 | | 4 | 13 | - | 6 Sega 9 ------------| L |----- Vectrex 1 12 | P | 7 Sega 6 ------------| |----- Vectrex 2 11 | | 8 Sega 4 ------------| |----- Vectrex 3 10 | | 9 Sega 3 ------------| |----- Vectrex 4 |_______| Notes: 1. Pins listed as Sega refer to the 9 pin male connector that the Sega Controller plugs into. Pins listed as Vectrex refer to the 9 pin female connector that plugs in the Vectrex. 2. Any Photo-Darlington Output Optoisolator should work. Digi-Key 4N31IS-ND will work. You can also get two optoisolators in one package. Thats all. Enjoy! Brian Holscher ------------------------------------------ For those of you who may attempt converting a Gen controller, take this into mind: On my Sega pcboard, the pin numbering was totally off. I would understand if the order was accidentally reversed, but the pinouts were actually scrambled... Take a look: Wire order & Listing: Pin Color 'Real' Pin # ~~~ ~~~~~ ~~~~~~~~~~~~ 1 Black 8 2 Brown 1 3 Red 2 4 Green 5 5 Orange 3 6 Yellow 4 7 Gray 7 8 Blue 6 9 White 9 Did anyone else notice this? I don't know if this is 'standard' or what, but I recommend checking the pinouts before you start converting your pad. Addendum by Rob Mitchell: ========================= Hi ... when I did my first Genesis conversion .. I used a controller 1650 that was made in China .... horrors. Don't even try. Please make reference to modifying only those made in Taiwan which has a much more easily modifiable circuit board. I don't know about the ones made in Malaysia or Japan. One of my modifications had the metal ball shorting the +5 and -5 which would make the Vec blank out (scary!). This took a while to diagnose. Use electrical tape to correct.