In 1980, British company Sinclair released their ZX80 computer for $199.95.
One year later, they released the new and improved ZX81
. Compared to the ZX80, the ZX81 was much cheaper, at only $99.95, the first computer for under $100. The ZX81 has the same microprocessor and runs at the same speed as the ZX80, but it has a better BASIC programming language and is cheaper to produce, due to having fewer chips and a simpler design.
Although cheap and quite popular, the ZX81 was, well, cheap. The keyboard is a ‘touch sensitive membrane’, a flexible plastic surface with the actual switches under the surface. While easy to clean and water resistant, it is very difficult and slow to type on, because you have to press hard and very deliberately to use the tiny, closely-spaced keys. Touch-typing is impossible. Resourceful users hacked into their system and added their own ‘real’ keyboard, external to the system.