Trackballs
This page should contain brief descriptions of various trackballs available, and details of their setup. If any one portion of the page starts getting a little too long, a seperate page may be started for that topic.
Contents
Mini Trackballs
2.25" Trackballs
Available from Happ, Suzo, Ultimarc and others.
3" Trackballs
Available from Happ, Suzo, Ultimarc and others.
4.5" Atari Trackballs (Missile Command, Atari Football)
These giant trackballs are sometimes known as 4-inch, but are actually four and a half inches in diameter. They were some of the first trackballs put into use, and are made of machined aluminum; clearly designed to survive intense abuse.
Putting one of these in your control panel is quite a commitment in terms of real estate. The metal frame is 6" square, 3.5" tall, and the optical boards stick an aditional 2 inches beyond two of the corners, an effective 64 square inch footprint.
Happ sells a 4.5" trackball. The ball itself is usable in an Atari 4.5" (a 4.5" diameter sphere is a 4.5" diameter sphere), but the mechanism itself is a different, less industrial design.
Any 4.5" diameter ball, particularly a candle-pin and/or duck-pin bowling ball, is a swap-out replacement for the 25+ year old originals.
The original optical boards on these are fairly easy to interface with an Opti-PAC (and therefore most other optical control interfaces). This is the pin-out for the 10-pin molex plug found on the optical boards:
| 1 | no signal |
| 2 | no signal |
| 3 | no signal |
| 4 | Axis 1 |
| 5 | no signal |
| 6 | no signal |
| 7 | no signal |
| 8 | Axis 2 |
| 9 | +5v |
| 10 | ground |
There were a number of slightly different boards with this same pin-out.
On an Opti-PAC, the "A/HI" jumper should be set.
There are a few vendors that sell replacement bearings and steel roller-shafts for these (they are often referred to as 4" trackball rollers).
