[Coco] Good games for wico trackball

[Torsten Dittel]

jeremy michea <jmichea at ...> writes:

> I don't believe the Wico's have a switch to put them in a true analog 
> trackball mode and are strictly digital and work more or less like a 
> joystick, at least the 2600 version was digital only.
> 
> You'll enjoy games like Polaris a little more but it's not a true 
> trackball experience unfortunately.

I have one of these (WICO part #72-4550) and can confirm it *behaves* like
an analog trackball. Of course it is not using potentiometers (like the
analog CoCo mice) nor does it work like a digital joystick (with 9 discrete
directional states), but rather more like a (digital) opto-mechanical mouse
(with two incremental rotary encoders for x and y direction). However, the 4
resulting digital signals are not fed directly into the CoCo, but rather
processed by a WICO custom chip (Motorola SC87152P, I guess it is based on
the MC6805) which will calculate a 64x64 coordinate pair out of the
movement, which is then output via two DACs (discrete R/2R network) as the
corresponding voltage for each x and y direction.

Some more details can be found in this patent (USP#4493992 by David A.
Geller/WICO): http://www.google.com/patents/US4493992

Regards,
Torsten