Twiddler
The Twiddler is a chorded keyboard and mouse allowing one to type with a single hand. History 
The first Twiddler was launched in 1992 by the HandyKey Corporation. Handkey was purchased in 2007 by the Canadian firm Tek Gear. Specification 
The original Twiddler used a serial port for communication and a PC AT keyboard port for power. This was replaced with USB for the Twiddler 2. The third generation Twiddler, the Twiddler 3, natively communicates using USB or Bluetooth and provides haptic feedback through an optionally installed module. References

Computer keyboard models
Computer-related introductions in 1992