NOTE: This writeup was done by Mitch Orman for a circuit developed by Jay Tilton. I will remove it or replace it with a link if either one requests me to.
These two guys also have great pages of their own:
This circuit is similar to a masterplay but also works with the games Qix, MsPacman, and Vanguard, because a masterplay does not connect up 500k ohms for the maximum resistance, only an open circuit which those three games don't like. (This info was discovered by Jay Tilton). I've opened a masterplay and it was based on two 4016 chips, but didn't trace the circuit through.
The following is the setup I use and recommend:
Of course, that dual psx adapter needs to be used with two genesis adapters (kind of strange to convert analog to digital and then back to analog :)
One last note before I turn it over to Jay and Mitch: you can't connect the adapter circuit to the 5200 with a spare 5200 controller cable because it doesn't have a wire for the 5v signal. Go buy a dsub-15 extension cable from an electronic or computer store instead.
materials needed: [2] 4052 (8-to-2 analog switch) [4] 10 kohm resistor [1] 9-pin male Dsub connector (for 2600 joystick connection) [1] 15-pin male Dsub cable (for 5200 port connection) [1] 15-pin female Dsub connector (for 5200 controller connection) Pinouts ====== 5200 port --------- 15-pin MALE D-sub connector on the console. 1 8 ___________________ \ o o o o o o o o / \ o o o o o o o / --------------- 9 15 1. Keypad right column (3, 6, 9, #) 2. Keypad middle column (2, 5, 8, 0) 3. Keypad left column (1, 4, 7, *) 4. Start, Pause and Reset column 5. Keypad third row (7, 8, 9) and Reset 6. Keypad second row (4, 5, 6) and Pause 7. Keypad top row (1, 2, 3) and Start 8. Keypad bottom row (*, 0, #) 9. Pot common 10. Horizontal Pot 11. Vertical Pot 12. +5VDC 13. Bottom side buttons 14. Top side buttons 15. 0V (GND) Digital controller plug ----------------------- 9-pin FEMALE D-sub connector on the joystick. 5 4 3 2 1 _____________ \ o o o o o / -\ o o o o / --------- 9 8 7 6 1. /North 2. /South 3. /West 4. /East 5. +5V (Sega) 6. /Button 1 7. +5V (Atari) 8. GND 9. /Button 2 4052 (8-to-2 analog switch) --------------------------- ________ 1X0 |1 \/ 16| VCC 1X2 |2 15| 2X2 1Y |3 14| 2X1 1X3 |4 13| 2Y 1X1 |5 4052 12| 2X0 /EN |6 11| 2X3 VEE |7 10| S0 GND |8_______9| S1 Schematics ========== Connect the +5 volts pins of the port and controller directly together Connect the GND pins of the port and controller directly together. Connect the 2600 fire line (pin A6) to 5200 primary fire button (5200 pin 13) The horizontal direction Digital Analog Converter ------------------------------------------------- --|1 \/ 16|--+5 volts | | --|2 15|---------->low voltage 10K Resistor to H pot | | --|3 14|---------->high voltage 500K Resistor to H pot | | --|4 4052 13|---------->5200 Pot common | | --|5 12|-- | | +--|6 11|---------->middle voltage 250K Resistor to H pot | | | +--|7 10|-------+-->2600 port Left (pin A3) | | | | GND--|8_______9|--+------->2600 port Right (pin A4) | | 10k< 10k< < < | | +----+--+5 volts The vertical direction Digital Analog Converter ----------------------------------------------- --|1 \/ 16|--+5 volts | | --|2 15|---------->low voltage 10K Resistor to V pot | | --|3 14|---------->high voltage 500K Resistor to V pot | | --|4 4052 13|---------->5200 Pot common | | --|5 12|-- | | +--|6 11|---------->middle voltage 250K Resistor to V pot | | | +--|7 10|-------+-->2600 Down (pin A2) | | | | GND--|8_______9|--+------->2600 Up (pin A1) | | 10k< 10k< < < | | +----+--+5 volts