Does anyone know the pinout/schematic for the MBX joystick?

[masschamber]

I have a working mbx unit, but no joystick, I don't see any reason I can't build a joystick for it if I know what the pinout is (the schematic would be nice too since I wouldn't need to work backwords)  

I've also head conflicting information on it working with as a ti99/4a joystick, if it does I assume it uses the same matrix as the joystick and then the pot is on one of the unconnected pints.  Can anyone confirm if it does or doesn't?  I don't want to send voltage where it doesn't belong.

[Flottmann1]

there is no use knowing only the pin assignment, you have to consider more,

 

I have instructions from a TI friend who converted a Joystick, but unfortunately it is in German !

Edited May 26, 2020 by Flottmann1

[masschamber]

8 hours ago, Flottmann1 said:

there is no use knowing only the pin assignment, you have to consider more,

 

I have instructions from a TI friend who converted a Joystick, but unfortunately it is in German !

I'm aware of the matrix configuration of the standard joystick, I know the resistance of the potentiometers just the pinout would be enough to make sure I don't fry anything.  Obviously a schematic or even foreign language instructions could get a good chunk there.

[matthew180]

On 5/26/2020 at 6:05 AM, Flottmann1 said:

but unfortunately it is in German !

There are a lot of German speaking people here on the forum, and they are also really nice people.  I'm sure some of them would help decipher any technical information if the documents were posted.

[Flottmann1]

Oliver Arnold from the German TI Club Errorfree will soon post instructions for the modification at AtariAge,

 

he now has a PC Game Pad rebuild to a MBX Joystick and  two TI joysticks at the same time.

 

here a Picture from the old configuration (at Birkenau/Germany 2017)

[publicarni]

MBX Joystick
=========

About 2002 I got a MBX expansion system without joysticks. Luckily a friend of
me had an MBX joystick and gave it to me for analysing.
So I learned to understand the functions of the pins and made it possible to modify a PC analog joysticks to a MBX.
On the picture above from Flottman1 you see my first prototyp.
The second one is a Saitek analog joystick (it costs only 9 Euro).
Last week I modified a game pad, not only for MBX also for 2 TI-Joysticks.

The MBX-Joystick uses 3 potentiometers for the direction of X, Y, and
Z. In the MBX-System the different voltage is compared with an analog to digital converter. 

The four function keys use the same principle. Pressing one (or more) of them selects
one of the 4 resistors to get a different voltage.

 

MBX sheme:

9 pin SUB-D     (all resistors KOhm)

1)---(GND)-----------*---------------------------------------
                     !
2)---(+5V)-----------!---*-----------------*----*------------
                    +-+  !                 !    !
3)---(X-axis )-----%!5!  !                 !    !
                    +-+  !                 !    !
                     !   !                 !    !
                     +---+      +-----+    !    !
                             +--! 2,0 !----+    !
                             !  +-----+         !
                             !                  !
                             !                  !
                             !  +-----+     _   !
4)---(keys)------------------*--!18,6 !----/ ---*   Trigger
                             !  +-----+         !
                             !                  !
                             !  +-----+     _   !
                             *--! 3,8 !----/ ---*   Left
                             !  +-----+         !
                             !                  !
                             !  +-----+     _   !
                             *--! 7,8 !----/ ---*   Center
                             !  +-----+         !
                             !                  !
                             !  +-----+     _   !
                             *--! 1,6 !----/ ---*   Right
                     (-)        +-----+
5) not used           !
                     +-+
6)---(Y-axis )------%!5!
                     +-+
7) not used           !
                     (+)

 

                     (-)
                      !
                     +-+
8)---(Z-axis )------%!5!
                     +-+
9) not used           !
                     (+)

Please note:
For the keys, I use adjustable 20K resistors (cause I didn't open the original MBX joystick to get the correct resistance, in cause of damage).
Using adjustable resistors may it possible to trim the keys perfectly.
One prototyp joystick uses a potentiometer with 150KOhm, this works well too.

Software:
I use the MBX-Test-Tool from Barry Boone (ftp://ftp.whtech.com/). This helps to trim the function keys excellent.

 

Now you will see the modified Game Pad playing Baseball wit the MBX-System and

playing RISK, two players with TI-Joysticks...