Digital Technologies/Electronics: Joysticks and trackballs (1955 – 1970)

Joysticks and trackballs (1955 – 1970)

For the purpose of pointing to objects on radar screens and to input track information, increasingly advanced joystick systems were developed by TNO starting in 1955. A joystick is an instrument that converts a mechanical movement of a control stick, slider or rotating ball in the X and Y direction into two proportional analogue electrical voltages via two (or more) potentiometers. These two variable voltages move a symbol across a screen. This information can be used to mark certain information in the image (e.g. a radar echo).

The photos below show the technical and mechanical advancements over time.

Joystick with a mechanical-electrical conversion (1955)
Joystick with a mechanical-electrical conversion using two wired resistors (1955)

 

Joystick with a mechanical-electrical conversion (1955)
Joystick with a mechanical-electrical conversion (1955)

 

Joystick met mechanisch-elektrische overbrenging (1955)
Experimental joystick with a mechanical-electrical conversion (1955)

 

Experimental joystick with a mechanical-electrical conversion using four potentiometers (1956)
Experimental joystick with a mechanical-electrical conversion using four potentiometers (1956)

 

Joystick met mechanisch-elektrische overbrenging (1957?)
Experimental joystick with a mechanical-electrical conversion using two sideways placed potentiometers (around 1957-1958)

 

Trackball (195?) counting light holes in a rotating disk
Trackball using a billiard ball (early 60’s) counting stripes on two perpendicular rotating disks

 

Trackball gebaseerd op een biljartbal
Trackball built around a billiard ball using integrated circuits and a separate push button (mid 60’s). A chopper disk and a light cel on each of the axles was used to determine the rotation. The electronics use the SN7400-series of ICs.

 

Air pump for the air bearing of the billiard ball
Air pump for providing an air bearing of the billiard ball above making it almost frictionless. 

 

Open trackball
Trackball (mid 60’s) with the electronics in water tight enclosures 

 

Prototype of a 5-bit read-out unit for the axis rotation. The five contact strips are visible on the photo. Smaller, later versions of this prototype can be seen above
Prototype of a 5-bit read-out unit for the axis rotation. The five contact strips are visible on the photo. Smaller, later versions of this prototype can be seen above