Here I'll give you a brief summary of what happened with the ZX Spectrum, it's forerunners, and what happened after the bubble burst:

It all started with a man called Sir Clive Sinclair. Born in 1940, he formed a company called Sinclair Radionics Ltd in 1961 at the age of 21. Being the ever entrepreneur he has always proved to be, he was the inventor of the first electronic calculator. Sinclair Radionics also produced multimeters, watches and other projects, including hi-fi equipment up until the company was sold in 1979. Due to pressures from Sir Clive, a previous company under his control was renamed to Science of Cambridge in the same year.

Science of Cambridge started the ZX80 project in 1979 which was the first computer for sale in the UK at the time for under £100. You could also buy the ZX80 in "kit" form for home assembly for under £80. This truly put the power of computing within the reach of everyone. It was released in 1980, the same year the company changed their name to Sinclair Computers Ltd.

The next year saw the company rename again, this time to the familiar Sinclair Research Ltd title and also released the ZX81. This computer sold for £49.95 as a kit, or £69.95 as an assembled product. Not only did the ZX81 have a more robust appearance than it's predecessor, but it was blessed with a bigger ROM & the ability to upgrade the internal RAM (with an external interface) to a whopping 16K (for just under £50.) Both the ZX80 & the ZX81 were black & white, with blocky 8x8 pixel graphics.

All hail the Spectrum! Yes that's right, in 1982 the ZX Spectrum was announced. Originally dubbed the ZX82, or the ZX81 colour, the ZX Spectrum was blessed with 16 colour graphics, a professional looking case (with rubber keys) and came in two flavours: A 16K (£125) or an amazing 48K (£175) version. Some thought the computer was escaping from the accessible price of the ZX80 or ZX81, but the sales rocketed. The company was making record profits and at the time everyone wanted a Spectrum.

Cruising on the back of their successes, Sinclair Research decided to make a break into the US market after a deal was signed with Timex in 1982, shortly before the release of the Spectrum. This deal gave Timex the hardware rights to use the Sinclair's motherboard designs & in that year they released their version of the ZX81, the "TS1000." The next year saw the Timex version of the Spectrum shown to the public at the CES in Las Vegas. Dubbed the "TS2000", the American version was largely incompatible with the Spectrum. It was available, like the Spectrum, in both a 16K and a 48K version. Also in 1983, the Spectrum prices were reduced to under a £100 for the 16K version and under £130 for the 48K. The ZX81 was also cut to just under £40. At this point the Spectrum was being produced at 50,000 units a month. Demand was very high.

1984 saw the birth of a new Spectrum - The "+". The Spectrum+ did away with the rubber keys, in favour of plastic ones, and also had a rugged, square, design which was based on the QL - the business version of the spectrum released the same year (and also a big commercial flop.) This design would prove to be quite popular with similar styling for the Spectrums to come. Other than that, the Spectrum+ differences were quite small. Retailing at £180, however, it still outsold the £130 Spectrum from two years before.

In 1985 there was a lot of ground being made by other computer manufacturers such as the Commodore 64, which although initially twice the price had started to take some of SInclair's market share. Change was on the cards when the Spectrum+ inherited a younger slicker brother - The ZX Spectrum 128. The new model had better sound and more RAM. Plus it had "grown-up" features like a monitor port (although proprietary) and MIDI capability to control musical instruments. Due to large stocks, still, of the Spectrum+, the ZX Spectrum 128 launch was delayed until January 1986.

Also in that year, sadly, Sinclair Research announced that they had sold all rights to the Spectrum computers, the Sinclair & Spectrum names and the intellectual property rights & all Spectrum stock. Rival computer company, Amstrad, were the buyer and they parted with a reported £5 Million. This year also saw the arrival of a new Spectrum re-badged and produced by the new company - The Spectrum +2. The +2 had all of the features of the 128 plus a built in tape drive (named the "datacorder".) It also had a sprung keyboard, for a better feel, and also didn't have any of the normal spectrum commands and functions written across the keys. The biggest visual difference to other models of Spectrum, was the fact that it was completely grey. All models of Spectrum before and after were black in appearance.

1987 saw the launch of the last production model of the Spectrum range - The +3. The ZX Spectrum +3 had a diskette drive in the place of the datacorder of the +2 and had lots of other changes, both in software and hardware. What that meant to the end user was a lack of support for some current 128K games, and quite a few 48K games - whilst not really providing anything extra to the overall performance or feature set of the Spectrum - other than the diskette drive. Also in this year, Amstrad released the +2A which was basically a Spectrum +3 with a datacorder, with all the problems too.

From 1987 onwards, sales of the Spectrum +2A & +3 continued to decline until, finally, in December of 1990, the production line & a significant point in computing history within the UK came to a close.

Image sources: Z80 Heaven, Public Domain