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ZX80

Type	Home computer
Release date	1980
Introductory price	£99.95 (£319 at 2012 prices)
Discontinued	1981
Units shipped	100,000[1]
Media	Cassette tape
Operating system	Sinclair BASIC
CPU	Z80 @ 3.25 MHz (most machines used the NEC μPD780C-1 equivalent)
Memory	1 KB (16 KB max.)
Successor	ZX81

The Sinclair ZX80 is a home computer brought to market in 1980 by Science of Cambridge Ltd. (later to be better known as Sinclair Research). It is notable for being the first computer (unless you consider the MK14) available in the United Kingdom for less than a hundred pounds (£99.95). It was available in kit form, where purchasers had to assemble and solder it together, and as a ready-built version at a slightly higher cost for those without the skill or inclination to build their own unit. The ZX80 was very popular straight away, and for some time there was a waiting list of several months for either version of the machine.

Description[link]

Name[link]

The ZX80 was named after the Z80 processor with the 'X' for "the mystery ingredient".^[2]

Hardware[link]

Internally, the machine was designed by Jim Westwood around a Z80 central processing unit with a clock speed of 3.25 MHz, and was equipped with 1 kB of static RAM and 4 kB of read-only memory (ROM). The ZX80 was designed around readily available TTL chips; the only proprietary technology was the firmware. While the successor ZX81 used a semi-custom chip (a ULA or Uncommitted Logic Array), this merely combined the functions of the earlier hardware onto a single chip — the hardware and system programs (except the BASIC versions) were very similar, with the only significant difference being the NMI-generator necessary for slow mode in the ZX81. (See ZX81 for technical details.) Both computers can be made by hobbyists using commercially available discrete logic chips or FPGAs.

Firmware[link]

The ROM contained the Sinclair BASIC programming language, editor, and operating system. BASIC commands were not entered by typing them out but were instead selected somewhat similarly to a scientific calculator - each key had a few different functions selected by both context and modes as well as with the shift key.

Case[link]

The machine was mounted in a tiny white plastic case, with a one-piece blue membrane keyboard on the front; it owed its distinctive appearance to industrial designer Rick Dickinson. There were problems with durability, reliability and overheating (despite appearances, the black stripes visible on the top rear of the case are merely cosmetic, and are not ventilation slots).

Video output[link]

Display was over an RF connection to a household television, and simple offline program storage was possible using a cassette recorder. The video display generator of the ZX80 used minimal hardware plus a combination of software to generate a video signal. This was an idea that was popularised by Don Lancaster in his 1978 book The TV Cheap Video Cookbook and his "TV Typewriter".^[3] As a result of this approach the ZX80 could only generate a picture when it was idle, i.e. waiting for a key to be pressed. When running a BASIC program, or even when pressing a key for any input, the display would, therefore, black out momentarily while the processor was busy. This made moving graphics difficult since the program had to introduce a pause for input to display the next change in graphical output. The later ZX81 improved on this somewhat because it could run in a "slow" mode while creating a video signal, or in a "fast" mode without generating a video signal (typically used for lengthy calculations). Another issue was that the main RAM was used to store the screen display, with the result that the available screen size would gradually decrease as the size of a program increased (and vice versa) - with 1kB RAM, running a 990 byte program would result in only one row of characters being visible on the screen; a full screen (32*24) would leave only 384 bytes to the programmer.

Video output was strictly black-and-white, character-based. However, the character set included some simple block-based graphics glyphs, allowing crude graphics to be accomplished, with some effort. One advantage to using monochrome video is that different colour broadcast standards (e.g. PAL, NTSC) simply weren't an issue when the system was sold outside the UK.

Expansion[link]

Other than the built-in cassette and video ports, the only provided means of expansion was a slot opening at the rear of the case, which exposed an expansion bus edge connector on the motherboard. The same slot bus was continued on the ZX81, and later the ZX Spectrum, which encouraged a small cottage industry of expansion devices, including memory (Sinclair produced RAM expansion packs for the ZX80: the original ZX80 RAM Pack held either 1, 2 or 3 KB of static RAM; a later model held 16 KB, using dynamic RAM chips (DRAM)), printers, and even floppy drives.

Following the ZX81's release, a ZX81 8 KB ROM was available to upgrade the ZX80 at a cost of around 20% of a real ZX81. It came with a thin keyboard overlay and a ZX81 manual. Simply taking off the top cover of the ZX80 and prying the old ROM from its socket and carefully inserting the new ROM and adding the keyboard overlay, the ZX80 would now function almost identically to the proper ZX81 - except for SLOW mode, due to the differences in hardware between the two models. The process was easily reversed to get the ZX80 back to its old self.

One of the most common modifications by hobbyist users was to move the motherboard into a larger case, with a full-size keyboard. This had the dual advantages of making the machine easier to type on, while increasing ventilation to the motherboard (reducing the likelihood of overheating).

Versions[link]

The UK version of the machine was the standard, and only changes that were absolutely necessary to sell units in other markets were made. In fact, the only real change made in most markets involved the video output frequency (the ZX80 used an external power transformer, so differences in AC line frequency and outlet were not an issue to the machine itself). One outcome of this is that the machine had some keyboard keys and characters that were distinctly British: "Newline" was used instead of "Enter", "Rubout" instead of "Backspace" or "Delete", and the character set and keyboard included the Pound symbol, relatively unusual for its day.

Reception[link]

Sales of the ZX80 reached about 50,000 — an unheard of number for the day which contributed significantly to the UK leading the world in home computer ownership through the 1980s. Owing to the unsophisticated design and the tendency for the units to overheat, surviving machines in good condition are quite uncommon and can fetch high prices by collectors.

The primary audience for such computers at the time was hobbyists, and the ZX80 was primarily marketed towards that end. In the US, the ZX80 was available in two forms: a prebuilt unit for US$199.95, or a "kit" version, which provided all the parts but required assembly, for US$149.95. Capitalizing on the price, the system was advertised (in computing and electronics magazines) with the slogan "The first personal computer for under $200".^[4]

Clones[link]

There were also unauthorised clones of the ZX80, such as the MicroAce (produced in the USA), and from Brazil the Nova Eletrônica/Prológica NE-Z80 and the Microdigital TK82.^[5][6]

Notes[link]

External links[link]

Wikimedia Commons has media related to: Sinclair ZX80

• Planet Sinclair:ZX80
• Review of Sinclair ZX80 from 1980
• Showcase of Sinclair ZX80
• Scot's ZX80 site

v t e Sinclair computers, derivatives, and clones (ZX80/81, ZX Spectrum, and QL clones) Sinclair Research ZX80 ZX81 ZX Spectrum, Spectrum+, Spectrum 128 QL Timex Sinclair TS 1000 TS 1500 TS 2048 TC 2048 TS 2068, TC 2068 Amstrad ZX Spectrum +2 ZX Spectrum +3 Cambridge Computer Z88 Compatible systems Jupiter Ace SAM Coupé Didaktik Dubna 48K Hobbit Pentagon Scorpion Sprinter One Per Desk CST Thor Q40/Q60 Komputer 2086 Sinclair Research Peripherals ZX Printer ZX Interface 1 ZX Interface 2 ZX Microdrive Timex Peripherals TS2050 FDD FDD3000

Sir Clive Sinclair
Sinclair meeting young inventors in Bristol, England in 1992
Born	Clive Marles Sinclair (1940-07-30) 30 July 1940 (age 71) near Richmond, Surrey
Occupation	Inventor, entrepreneur
Spouse	Ann Trevor-Briscoe (1962-1985) Angie Bowness (2010-present)
Children	Belinda, Crispin, Bartholomew
Parents	George William Carter Sinclair Thora Edith Ella Marles

Sir Clive Marles Sinclair (born 30 July 1940) is an English entrepreneur and inventor, most commonly known for his work in consumer electronics in the late 1970s and early 1980s.

After spending several years as assistant editor of Practical Wireless and Instrument Practice, Sinclair founded Sinclair Radionics in 1961, where he produced the first slim-line electronic pocket calculator in 1972 (the Sinclair Executive). Sinclair later moved into the production of home computers and produced the Sinclair ZX80, the UK's first mass-market home computer for less than GB£100, and later, with Sinclair Research, the ZX81 and ZX Spectrum; the latter is widely recognised for its importance in the early days of the British home computer industry. Sinclair stated in 2010 that he does not use computers himself, using the telephone in preference to email.^[1]

Knighted in 1983, Sinclair formed Sinclair Vehicles and released the Sinclair C5, a battery electric vehicle that was a commercial failure. Since then Sinclair has concentrated on personal transport, including the A-bike, a folding bicycle for commuters that weighs 5.5 kilograms (12 lb) and folds down small enough to be carried on public transport.

Early life, family and education[link]

Sinclair's father and grandfather were engineers; both had been apprentices at Vickers the shipbuilders. His grandfather George Sinclair was an innovative naval architect who got the paravane, a mine sweeping device, to work. George Sinclair's son Bill Sinclair wanted to take religious orders or become a journalist. His father suggested he train as an engineer first; Bill became a mechanical engineer and remained in the field. At the outbreak of World War II in 1939 he was running his own machine tools business in London and later worked for the Ministry of Supply.^[2]

Clive Sinclair was born to George William Carter Sinclair (known as Bill) and Thora Edith Ella Marles in 1940 near Richmond, then in Surrey. He and his mother left London to stay with an aunt for safety in Devon, where they eventually travelled to Teignmouth. A telegram arrived shortly afterwards, bringing the news that their home in Richmond had been bombed. Sinclair's father found a house in Bracknell in Berkshire. His brother Iain was born in 1943 and his sister Fiona in 1947.^[2]

At an early age Sinclair designed a submarine. During holidays he could pursue his ideas and teach himself what he wanted to know. Sinclair had little interest in sports and found himself out of place at school. He preferred the company of adults, which he got only from his family.^[3]

Sinclair attended Box Grove preparatory school, excelling in mathematics. By the time he was ten, his father had financial problems. He had branched out from machine tools and planned to import miniature tractors from the U.S.; he had to give up the business.^[3] Because of his father's problems, Sinclair had to move school several times. Sinclair took his O-levels at Highgate School in London in 1955 and A-levels in physics, pure maths, and applied maths at St. George's College, Weybridge.^[4]

During his early years, Sinclair earned money mowing lawns and washing up, and earned 6d (old pence) more than permanent staff in a cafe. Later he went for holiday jobs at electronic companies. At Solatron he enquired about the possibility of electrically propelled personal vehicles. Sinclair applied for a holiday job at Mullard and took one of his circuit designs; he was rejected for precociousness. While still at school he wrote his first article for Practical Wireless.^[4]

Sinclair did not want to go to university when he left school just before his 18th birthday; he wanted to sell miniature electronic kits by mail order to the hobby market.^[5]

Career[link]

Sinclair Radionics[link]

Sinclair's Micro Kit was formalised in an exercise book dated 19 June 1958 three weeks before his A-levels. Sinclair drew a radio circuit, Model Mark I, with a components list: cost per set 9/11 (49½p), plus coloured wire and solder nuts and bolts, plus celluloid chassis (drilled) for nine shillings (45p). Also in the book are advertisement rates for Radio Constructor (9d (3¾p)/word, minimum 6/- (30p)) and Practical Wireless (5/6 (27½p) per line or part line).^[6]

Sinclair estimated producing 1,000 a month, placing orders with suppliers for 10,000 of each component to be delivered.^[6]

Sinclair wrote a book for Bernard's Publishing, Practical transistor receivers Book 1, which appeared in January 1959. It was re-printed late that year and nine times subsequently. His practical stereo handbook was published in June 1959 and reprinted seven times over 14 years. The last book Sinclair wrote as an employee of Bernard's was Modern Transistor Circuits for Beginners, published in May 1962.^[7] At Bernard Babani he produced 13 constructors' books.

In 1961 Sinclair registered Sinclair Radionics Ltd. His original choice, Sinclair Electronics, was taken; Sinclair Radio was available but did not sound right. Sinclair Radionics was formed on 25 July 1961.

Sinclair made two attempts to raise startup capital to advertise his inventions and buy components. He designed PCB kits and licensed some technology. Then he took his design for a miniature transistor pocket radio and sought a backer for its production in kit form. Eventually he found someone who agreed to buy 55% of his company for £3,000 but the deal did not go through.

Sinclair, unable to find capital, joined United Trade Press (UTP) as technical editor of Instrument Practice. Sinclair appeared in the publication as an assistant editor in March 1962. Sinclair described making silicon planar transistors, their properties and applications and hoped they might be available by the end of 1962. Sinclair's obsession with miniaturisation became more obvious as his career progressed. Sinclair undertook a survey for Instrument Practice of semiconductor devices, which appeared in four sections between September 1962 and January 1963.^[8]

His last appearance as assistant editor was in April 1969. Through UTP, Sinclair had access to thousands of devices from 36 manufacturers. He contacted Semiconductors Ltd (who at that time sold semiconductors made by Plessey)^[9] and ordered rejects to repair. He produced a design for a miniature radio powered by a couple of hearing aid cells and made a deal with Semiconductors to buy its micro-alloy transistors at 6d (2½p) each in boxes of 10,000. He then carried out his own quality control tests, and marketed his renamed MAT 100 and 120 at 7s 9d (38¾p) and 101 and 121 at 8s 6d (42½p).^[10]

Science of Cambridge[link]

Sinclair had formed another company, initially called Ablesdeal Ltd, in 1973. This changed name several times, eventually becoming Science of Cambridge Ltd in July 1977.^[11]

In June 1978 Science of Cambridge launched a microcomputer kit, the MK14, based on the National SC/MP chip. By July 1978, a personal computer project was under way. When Sinclair learnt the NewBrain could not be sold at below £100 as he envisaged, he turned to a simpler computer. In May 1979 Jim Westwood started the ZX80 project at Science of Cambridge; it was launched in February 1980 at £79.95 in kit form and £99.95 ready-built. In November, Science of Cambridge was renamed Sinclair Computers Ltd.

Sinclair Research[link]

ZX Spectrum (1982)

In March 1981, Sinclair Computers was renamed again as Sinclair Research Ltd and the Sinclair ZX81 was launched at £49.95 in kit form and £69.95 ready-built, by mail order. In February 1982 Timex obtained a license to manufacture and market Sinclair's computers in the United States under the name Timex Sinclair. In April the ZX Spectrum was launched at £125 for the 16 KB RAM version and £175 for the 48 kB version. In March 1982 the company made an £8.55 million profit on turnover of £27.17 million, including £383,000 government grants for the TV80 flat-screen portable television.

In 1982 Sinclair converted the Barker & Wadsworth mineral water bottling factory into the company's headquarters. (This was sold to Cambridgeshire County Council in December 1985 owing to Sinclair's financial troubles.) The following year, he received his knighthood^[12] and formed Sinclair Vehicles Ltd. to develop electric vehicles. This resulted in the 1985 Sinclair C5.

In 1984, Sinclair launched the Sinclair QL computer, intended for professional users. Development of the ZX Spectrum continued with the enhanced ZX Spectrum 128 in 1985.

In April 1986, Sinclair Research sold the Sinclair trademark and computer business to Amstrad for £5 million.^[11] Sinclair Research Ltd. was reduced to an R&D business and holding company, with shareholdings in several spin-off companies, formed to exploit technologies developed by the company. These included Anamartic Ltd. (wafer-scale integration), Shaye Communications Ltd. (CT2 mobile telephony) and Cambridge Computer Ltd. (Z88 portable computer and satellite TV receivers).

By 1990, Sinclair Research consisted of Sinclair and two other employees,^[11] and its activities have since concentrated on personal transport, the Zike electric bicycle, Zeta bicycle motor and the A-bike folding bicycle.

In November 2010 Sinclair told The Guardian newspaper that he was working on a new prototype electric vehicle called the X-1, to be launched within a year. "Technology has moved on quite a bit, there are new batteries available and I just rethought the thing. The C5 was OK, but I think we can do a better job now."^[13][14] The X-1 was slated to become available in July 2011 at the price of £595. However, as of April 2012, it had still not reached the market.^[15]

Personal life[link]

Sinclair married Ann Trevor-Briscoe in 1962, and has three children: Belinda, Crispin and Bartholomew. Clive and Ann divorced in 1985.^[16] In 2010 Sinclair married Angie Bowness, who has an only son Marcus Thornton. Despite his involvement in computing, he does not use the Internet, stating that he does not like to have "technical or mechanical things around me" as it distracts from the process of invention.^[17][18]

Sinclair has become a poker player. He appeared in the first three seasons of the Late Night Poker television series in Britain. He won the first season final of the Celebrity Poker Club spin-off, defeating Keith Allen.

Sinclair is a member of British Mensa, and was Chairman for 17 years from 1980 to 1997.^[12]

Sinclair was awarded an Honorary Degree (Doctor of Science) by the University of Bath in 1983.^[19]

See also[link]

• Micro Men, a one-off TV drama about Sinclair and Chris Curry.

Notes[link]

References[link]

External links[link]

• Sinclair Research website
• Sinclair in 1966 in Life magazine
• Sir Clive Sinclair at Planet Sinclair website
• Sinclair bows out. John Gilbert, Sinclair User, Issue 51, June 1986
• 'Move over Segway, I'm planning the C6'. Jonathan Duffy, BBC News Online, 5 August 2003
• British Mensa biography of Clive Sinclair
• I don't use a computer at all. Observer interview, 28 February 2010, with Simon Garfield.

This biographical article needs additional citations for verification. Please help by adding reliable sources. Contentious material about living persons that is unsourced or poorly sourced must be removed immediately, especially if potentially libelous or harmful. (August 2011)

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The ZX81 personal computer. Dickinson holds a patent for its design

Rick Dickinson is a British industrial designer.

Early life[link]

Dickinson graduated from Newcastle Polytechnic (now Northumbria University) in 1979 with a First Class Bachelor of Arts Honours degree in Design for Industry. The "Design for Industry" degree was the first of its kind, formerly a three-year "Industrial Design" degree. The new course with two additional terms for industrial placements, extended the degree to four years and the introduction of the term "sandwich".

Sinclair[link]

Dickinson joined Sir Clive Sinclair's Sinclair Research Ltd in December 1979, replacing John Pemberton who was leaving Sinclair to head up a new design centre for ITT in Harlow. Sinclair Research offices were at 6 Kings Parade, Cambridge.

Rick Dickinson was the in-house industrial designer of Sinclair Research Ltd. He designed the ZX80 and ZX81 home computers,^[1] including the touch-sensitive keyboard, as well as the rubber keyboard of the ZX Spectrum. He also designed the TV80 casing and Sinclair QL. Dickinson is a graduate of Newcastle Polytechnic, and worked for Sinclair as a student on one of his industrial placements from Newcastle Polytechnic before he had completed his degree.

The ZX81 won a British Design Council award in 1981. It won a Haus Industrieform award and is in a permanent collection in Essen. The Sinclair QL won an Italian design award at the Smau Industrial Design Award.

Post-Sinclair[link]

In 1986, he founded Dickinson Associates, an industrial design consultancy based in Cambridge. That year he produced the industrial design for an early laptop computer, the Cambridge Z88. In 1987 he was commissioned by Sir Alan Sugar to create the industrial design concept for Amstrad's first portable computer.

In 1989 Rick Dickinson, Christopher Curry (Acorn Computers), and Keith Dunning had a re-think of the famous MacArthur field microscope and Rick designed the Lensman microscope, a portable field microscope. In 1991 the Lensman microscope won the BBC design awards, The Prince Of Wales Award For Industrial Innovation And Production, Archimedes award for Engineering Excellence.

He produced the industrial design concepts and models of the first "Broad Band phone" for AT&T. Dickinson Associates created the industrial design, mechanical design, and production engineering design for the first GSM mobile phone "reference phone" design, for Rockwell. Dickinson Associates were also the designers of the Gizmondo handheld console (originally the Gametrac).

References[link]

External links[link]

Design portal

• Rick Dickinson interview: The Enigma of Design Part 1
• Rick Dickinson interview: The Enigma of Design Part 2
• Rick Dickinson interview: The Enigma of Design Part 3
• Planet Sinclair - Rick Dickinson
• Sinclair User magazine, Modest award winner sets the pace in micro design, August 1982
• Rick Dickinson's photos on Flickr
• ZX80 patent
• ZX81 patent

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