Inside the 7800 joystick are two resistors and what?

[Rob Mitchell]

Inside the 7800 joystick are two resistors and what appears to be a diode .. What is that for?

[+phoenixdownita]

It's only 2 resistors afaik:

 

http://www.the-liberator.net/site-files/retro-games/hardware/Atari-7800/atari-7800-joypad.htm

[Shawn]

It's a reflector diode. It's overkill and unneeded.

[Rob Mitchell]

Thanks .. I wonder why they put the diode there ..?

Edited March 16, 2016 by Rob Mitchell

[Hannacek]

I looks like the diode was used in the regular 7800 controller, but they left it out of the second controller they made because it was not necessary.

[Clint Thompson]

Inside the 7800 joystick are two resistors and what appears to be a diode .. What is that for?

What are you up to if I may ask?

[bratboy_y2k]

I was looking at getting some arcade control parts and building a controller for 2600/7800. Does this mean I can just do the build and not worry about the resistors and diode?

[CPUWIZ]

You don't need the diode, but the resistors are required.

[bratboy_y2k]

So that's on every button? As in direction and fire? Will it work normally on a 2600?

[bratboy_y2k]

Can anybody tell me the resistor values and which buttons they need to go on?

[+phoenixdownita]

From the 7800 FAQ on this very site:

http://www.atariage.com/7800/faq/index.html?SystemID=7800#cat2_9

 

Joystick Pinouts

 2600/7800 pinouts: _________________ \ o5 o4 o3 o2 o1/  \ o9 o8 o7 o6 /   \___________/  pin #  2600 control     7800 control   1    WHT- Up          WHT- Up   2    BLU- Down        BLU- Down   3    GRN- Left        GRN- Left   4    BRN- Right       BRN- Right   5    unused           RED- Button (R)ight (-)   6    ORG- Button      ORG- Both buttons (+)   7    unused (+5v)     unused (+5v)   8    BLK- Ground(-)   BLK- Ground(-)   9    unused           YLW- Button (L)eft  (-)   2600 control (button)  pin 6 ORG(+) --------------()------------BLK(-) pin 8                       Button  7800 control (buttons)                                         /----------YLW(-) pin 9                             Button L  /                       /---------()---| YLW splits                      /                \----///-----\ pin 6 ORG(+) -------| ORG splits           620 ohm  |---BLK(-) pin 8                      \                /----///-----/                       \---------()---|     620 ohm                            Button R   \RED splits                                        \----------RED(-) pin 5