The Minivac 601 was created by Claude Shannon and built in 1961 by Scientific Development Corporation. Designed as a logic trainer with functional memory and processing capability, though on such a basic level that you can physically see the data being processed, all 6 bits of it. Dispite this, simple binary arithmetic could be easily demonstrated.

The price of the unit was $85. Adjusted to 2019 prices that is $718 (£550). It used relays and switches to control all the operations. The motorised dial could be used to either input numbers or show the output.

While the 601 was not too successful as it was considered an expensive toy by technology companies, the next model 6010 with improved switches, new colour scheme and over 5 times the price was seen as a serious tool for employees to learn.