On This Day - 2nd November

George Boole was born in Lincoln, England. Largely self-taught, he became a mathematician and logician whose work would eventually have a profound influence on the development of digital computing.

In 1849 he became the first Professor of Mathematics at Queen's College, Cork (now University College Cork). His most famous work, An Investigation of the Laws of Thought, was published in 1854 and developed a mathematical approach to logic that became known as Boolean algebra.

Boole died in 1864, decades before electronic computers existed. Yet his ideas became fundamental to digital electronics: Boolean logic can be implemented using electronic switching circuits, providing the logical operations on which modern digital computers are built.

Sinclair launches the ZX Printer, a compact printer designed specifically for the company's ZX81 home computer. Priced at £49.95, it provided an affordable way for ZX81 owners to produce permanent copies of program listings and simple graphics at a time when conventional computer printers could cost several hundred pounds.

Rather than using conventional ink, ribbon or thermal printing technology, the ZX Printer used specially coated aluminium paper. One of two electrically heated styluses passed a current through the metallic coating, causing the aluminium to evaporate and exposing the black surface beneath. The resulting print was distinctive black-on-silver and, although crude by later standards, was remarkably inexpensive for a computer printer.

The printer produced 32 characters per line, corresponding to the ZX81's 256-pixel-wide display, and could reproduce the computer's graphics characters. It connected directly to the computer's expansion connector, with a pass-through connection allowing other peripherals to be attached.

The ZX Printer was originally intended for the ZX81 but remained compatible with later Sinclair machines. It could also be used with the ZX80 when fitted with the appropriate 8K ROM upgrade, and the same interface was retained on the ZX Spectrum. Consequently, the printer became one of the earliest Sinclair peripherals to span several generations of the company's computers.

The printer remained on sale for several years and eventually became less important as more conventional printers and interfaces became available. Sinclair discontinued it in 1984 after sales had declined, although the special paper continued to be available for a period afterwards.

Timex Sinclair launches the Timex Sinclair 2068 in North America. Based heavily on the Sinclair ZX Spectrum, the 2068 was developed by Timex Corporation in cooperation with Sinclair Research and was intended to bring an enhanced version of the Spectrum concept to the American market.

The TS2068 was considerably more than a straightforward American Spectrum. It used a Z80A processor running at approximately 3.58 MHz and included 48K of RAM, 24K of ROM, an AY-3-8912 sound chip, two joystick ports and a cartridge connector. Its improved Timex SCLD video hardware provided additional display modes, including a 512 × 192 monochrome mode and an enhanced colour mode.

The cartridge system was one of the most obvious differences from the British ZX Spectrum. Timex hoped that instant-loading ROM cartridges would make the machine more attractive to consumers accustomed to dedicated video-game consoles. The machine also had a full-size keyboard with hard plastic keys, rather than the Spectrum's distinctive rubber keyboard.

Despite its Spectrum heritage, the TS2068 was not fully compatible with ordinary ZX Spectrum software. Changes to the ROM, memory organisation and video hardware meant that many Spectrum programs would not run correctly. A Spectrum ROM cartridge was subsequently produced to improve compatibility, allowing a much greater proportion of the British Spectrum software library to be used.

Priced at $199.95, the TS2068 was technically an impressive machine for its price and offered features that would not appear on Sinclair's own 128K Spectrum until later. However, Timex's position in the rapidly changing American home-computer market was difficult, and the 2068 failed to achieve the commercial success that the company had hoped for.

The TS2068 nevertheless became an important part of the wider Sinclair story. It represented one of the most substantial developments of the original ZX Spectrum design and introduced features such as AY sound, improved graphics and cartridge software that would have a strong connection with later Sinclair machines.

Sinclair Research reported a pre-tax profit of £14.03 million for the year ending March 1983, up from £8.55 million the previous year. Turnover had doubled to £54.53 million. Sinclair said the company had sold more than 1.5 million personal computers worldwide since its formation in 1980, while continuing to expand into new products and markets.

Sinclair Research agreed to supply ZX81s and ZX Spectrums to China as part of an initiative to develop the country's home computer industry. The machines were to be shipped as kits to a factory in Guangzhou for assembly. Sinclair's UK distributor, Prism Microproducts, also secured a contract to organise exhibitions promoting British Sinclair-related hardware and software in the Chinese market.