Sinclair ZX80 Kit

If you are tired of System on Chip (SOC) black box packages that nobody knows what is in them, and you need a microscope just to look at, then you will be glad to learn that this computer has PDIP 74LS logic chips that you can hold and know what is inside. This makes it an ideal computer for a beginner.

If you remember this computer from the 1980s, then why not re-live your past and simultaneously introduce your children to the exciting world of digital electronics. This is a world where discrete 74 series logic chips could be connected together to build a programmable computer. A complete computer with a keyboard for programming in BASIC together with display output to a conventional television.

The ZX80 was the closest relative of the ZX81, because it was essentially an upgraded ZX80 with fewer components. A single uncommitted logic array (ULA) IC performed majority of the Boolean logic thereby reducing the chip count.

Sinclair also introduced an 8K ROM chip as a drop-in replacement upgrade for the ZX80 thereby allowing it to become fully compatible with the ZX81.

Looking for Components

This article shows how I made a replica ZX80 by buying all the parts from different places. The fun was in looking for the components and haggling. However, once or twice there were negotiations with a "lightsaber". I am pleased to say that Sir Alan Sugar’s advice of never paying the asking price helped here, and I managed to purchase many components at a discounted rate. Amstrad later bought Sinclair, so I wonder what Sir Alan Sugar and Sir Clive Sinclair think about my homemade kit as a product concept.

If you have any original logic chips in a ceramic package with gold pins, then ideally that is what you should use to make this replica, as it will look nicer. Alternatively, there are always the modern versions in a plastic package.

The components parts list is also the menu, so click on the component to see a photograph of it and some notes on where I managed to get it cheap.

ZX80 Components List

Storage Box

I am using a "Tuff Box" for storing the integrated circuits. I lined it with a thin piece of polystyrene so that the pins could be embedded in them. You should also take electrostatic discharge (ESD) precautions to protect your logic chips. In the process of searching for affordable components I managed to find some new electronic component sellers that are doing exceptionally well due to being mentioned by the legendary Peter Vis. :-)

This article is the parts list detailing the components, and I have plans of making another article showing the actual build, which I hope to make if I can get the time. Back in the 1980s, we had to use awful solders, however all that has changed now. Once you have all the components ready all you need is some nice quality solder. If you remember building the original kit at Christmas with your dad, then walk with me down the memory lane.

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