| [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.
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!
------------------------------------------
Addendums by Michael Bobroski:
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.
|
