ZX Printer - AbsoluteAstronomy.com

The Sinclair ZX Printer is a spark printer

Spark printer

A spark printer is an obsolete form of computer printer which uses a special paper coated with a layer of aluminium over a black backing, which is printed on by using a pulsing current onto the paper via two styli that move across on a moving belt at high speed. They were introduced in the late 1960s...

which was produced by Sinclair Research

Sinclair Research Ltd

Sinclair Research Ltd is a British consumer electronics company founded by Sir Clive Sinclair in Cambridge. Originally incorporated in 1973 as Ablesdeal Ltd., it remained dormant until 1976, and did not adopt the name Sinclair Research until 1981....

for its ZX81 home computer

Home computer

Home computers were a class of microcomputers entering the market in 1977, and becoming increasingly common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a single nontechnical user...

. It was launched in 1981, with a recommended retail price of £49.95

Pound sterling

The pound sterling , commonly called the pound, is the official currency of the United Kingdom, its Crown Dependencies and the British Overseas Territories of South Georgia and the South Sandwich Islands, British Antarctic Territory and Tristan da Cunha. It is subdivided into 100 pence...

.

The ZX Printer used special 4 inches (10.2 cm) wide black paper which was supplied coated with aluminium

Aluminium

Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....

oxide, this was electrically marked during the printing process to reveal its black under-surface. The printer's horizontal resolution was the same as the ZX81's video display, ie. 256 dots (pixels) or 32 characters (using the standard character definition). The print quality was crude, but no other printer was compatible with the ZX81 without the use of additional software and interface hardware.

The ZX Printer was also compatible with the earlier ZX80 computer (when fitted with the 8kB ROM upgrade) and the later ZX Spectrum

ZX Spectrum

The ZX Spectrum is an 8-bit personal home computer released in the United Kingdom in 1982 by Sinclair Research Ltd...

, and plugged directly into the expansion bus

Expansion bus

An expansion bus is made up of electronic pathways which move information between the internal hardware of a computer system and peripheral devices. It is a collection of wires and protocols that allows for the expansion of a computer.- History :The first kit-built microcomputers used a bus design...

connector via a short cable. The printer drew its power directly from the expansion bus, and was sold with a larger (1-2A

Ampere

The ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics...

) power supply for the ZX81 to accommodate the additional power drain. The Spectrum's user manual noted that this was not needed for the Spectrum as its default 1.1A

Ampere

power supply was sufficient.

See also