The Megaprocessor is a microprocessor built on a huge scale. It consists of seven panels, is two metres high and nearly ten metres end-to-end. It was built by James Newman, of Cambridge, as a hobbyist's project. Since the Megaprocessor is not based on any single computer or chip architecture, it is a unique machine, the only one of its kind in the world. It arrived at the Centre on 20 October 2016 and is currently on display in the foyer.
The project began with Newman's desire to learn about transistors. The transistor is the fundamental component of modern electronics. It switches or amplifies electrical power, allowing for the creation of logic circuits. Today they are mostly produced in integrated circuits, with millions or billions of them crammed onto a microchip. Newman used discrete transistors: individual components you can count in the palm of your hand.
This makes the Megaprocessor a huge recreation of a device that, in practical electronics, would be tiny. The advantage of this approach is educational. Newman said:
"Computers are quite opaque. Looking at them, itís impossible to see how they work. What I wanted to do was get inside and see whatís going on. Trouble is we canít shrink down small enough to walk inside a silicon chip. But we can go the other way; we can build the thing big enough that we can walk inside it. Not only that we can also put LEDs on everything so we can actually see the data moving and the logic happening.Ē
The Megaprocessor runs at a top speed of around 20khz and can be slowed down to 0.01hz. Programs can be halted and stepped through cycle by cycle.
256 bytes of RAM is included on a separate panel, with each bit represented by an LED. The board is approximately 2m2. On this scale, 32GB of RAM - the amount you'd find in a high-end home PC - would need a panel larger than the area of the United Kingdom.
There are over 10,500 LEDs and 40,000 individual transistors on the system. Newman made more than a quarter of a million solder joints during construction.
For more information on the Megaprocessor, please visit Newman's site, www.megaprocessor.com.
Manufacturer: James Newman
This exhibit has a reference ID of CH43063. Please quote this reference ID in any communication with the Centre for Computing History.