Plastic flip flops from the 1970s

Post this page to popular social media

We get donations of all types of calculator at The National Museum of Computing but rarely something like the BOBCAT. The Ball Operated Binary Calculator and Tutor (BOBCAT) was once used as part of an Open University Course.

Recently kindly donated and ably demonstrated by a visitor to TNMOC, the development of the BOBCAT is a curious ‘tale’ and you can find out more here in German.

Used in the early 1970s to support an OU Technology course, the BOBCAT did not use electrical impulses to drive its logic, rather metal balls which flipped the plastic ‘gates’ and enabled the device to count, add, subtract, multiply and divide; all in binary of course.

Demonstrating the principles of logic such as flip flops inside a computer, BOBCAT encouraged young people to want to find out more about how a real computer works.

With a little patience BOBCAT can be a useful demonstration tool, just make sure you are ready to catch the balls when they come out of the end of the process!

Apart from that, I really liked not having to pop out to buy any AA batteries.

A very clever piece of practical engineering that deserves its place in our Museum of Computing.

Did you encounter BOBCAT on an OU course? If you did, please get in contact with us and tell us about the use of this device.

Support us

The Museum has not received government or Lottery funding, so your help is needed.

Become a member »
Make a donation »
Become a volunteer »
Sponsor us »

Latest Tweets Follow