The Hori Track is a trackball controller for the Famicom.

There are only a few games that are compatible with the trackball and they are all sports games. There is a prototype that exists for the US version, but it was never released commercially.

A full controller is integrated into the device with large A and B buttons. This operates just as a standard expansion controler would.

The trackball can be oriented for either right or left hand play using a switch on the underside. The sensitivity of the trackball can also be adjusted between a “Hi” and “Lo” setting with a second switch.

The speed switch will modify the trackball read values before sending to the console. However, the orientation switch will not swap the axes before sending values.

Both of these switches have a bit in the third data byte that reflects their state.

The first byte of data is the same as a standard controller. The next two hold the following info:

Byte 2

7654 3210
|||| ++++- Axis 2, signed 4 bit, XOR with $F
++++------ Axis 1, signed 4 bit, XOR with $F

Byte 3

7654 3210
|||| ++++- Unknown (read and unused by games)
||++------ ID bits (1 or 2 depending on version)
|+-------- Speed switch (0: Hi, 1: Lo)
+--------- Rotation mode switch (0: R, 1: L)

I also scanned the manual. I haven’t transcribed or translated this yet. If anybody wants to translate it, I’ll add the translation here.