Developed at Manchester University by “Freddie” Williams, Tom Kilburn and Geoff Tootill, in size the Baby was anything but: more than 5m long and weighing a tonne (PDF). Its moniker was due to its role as a testbed for the experimental Williams-Kilburn tube, a means of storing binary digits (“bits”) using a cathode ray tube. This was a big deal because up until this point, computers had no cost-effective means of storing and flexibly accessing information in electronic form.



In technical terms, the Williams-Kilburn tube was the earliest form of random access memory, or RAM. The Baby’s memory consisted of one of these tubes, able to store up to 1,024 bits—equivalent to just 128 bytes. In contrast, the average computer today has RAM in multiples of gigabytes, more than a billion times bigger.





The Baby was only ever intended to be a proof-of-concept rather than to serve as a useful calculation tool. So once it had shown the new memory was reliable, attention shifted to building a more powerful and practical machine using the same concepts. This resulted in the Manchester Mark 1, which in turn was the model for the Ferranti Mark 1, the world’s first computer to be sold commercially, in February 1951.



While today nothing remains of the original Baby, a working replica is on display at the Museum of Science and Industry (MOSI) in Manchester. It’s well worth a visit to reflect on just how far computing has come.

