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Williams-Kilburn Tube

Frederic Williams, Tom Kilburn

The Williams Kilburn tube is a device created by Freddie Williams and Tom Kilburn in 1947. It is known as the first electronic random access memory (RAM) device. It could hold both programming and data electronically. Not only was everything electronic, but as can be inferred from the title of random access memory, the device did not need to read all the way through to find one bit of information, like it would have with previous machines.
The tube was essentially a cathode ray tube. It was made of metal and looks like a cylinder with a cone attached to one end. How it works is an electron ray goes in through the cylindrical end and “writes” through the conical end in a gridlike pattern onto a metal plate, which will hold the charge in the form of light, that is shown on a screen. If the point on the grid has a charge it is read as a 1, if not it is read as a zero. The tube is impossible to read without secondary machinery. Enter the Manchester “Baby”: the baby is a machine that was built specifically to test the Williams Kilburn tube. This testing was the first time a computer program had ever been run by a machine. The original tubes were only able to hold 256 bits, which is the equivalent of about 32 bytes of data.
This technology and event was not just a breakthrough for digital storage, being the first RAM device, but it also changed the way computers worked and showed what was possible for the future of machines being able to run autonomously.

The Computer History Museum. n.d. “Williams-Kilburn Tubes.” Computer History Museum. Accessed December 20, 2021. https://www.computerhistory.org/revolution/memory-storage/8/308.

PC Mag. n.d. “Williams tube.” PC Mag. Accessed December 20, 2021. https://www.pcmag.com/encyclopedia/term/williams-tube.

Norman, Jeremy. n.d. “The Williams Tube and the "Manchester Baby," the First Operational Stored-Program Computer Runs its First Program.” History of Information. Accessed December 20, 2021. https://www.historyofinformation.com/detail.php?id=672.

Richards, Mark. n.d. “Williams-Kilburn tube from an IBM 701 computer.” Computer History Museum. Accessed December 20, 2021. https://www.computerhistory.org/revolution/memory-storage/8/308/962?position=2.

University of Manchester. n.d. “Tom Kilburn and Freddie Williams.” Computer History Museum. Accessed December 20, 2021. https://www.computerhistory.org/revolution/memory-storage/8/308/961.