Editing ZX Spectrum (section)

== History ==
[[File:Sir Clive Sinclair on X-Bike Prototype.jpg|thumb|left|Sir [[Clive Sinclair]] riding an X-Bike prototype in 1990]]

The ZX Spectrum was conceived and designed by engineers at Sinclair Research, founded by English entrepreneur and inventor [[Clive Sinclair]], who was well known for his eccentricity and pioneering ethic.<ref name="bizhistory">{{cite web |last1=Oliver |first1=Phillip |title=ZX Spectrum: An enduring legacy |url=https://www.gamesindustry.biz/zx-spectrum-an-enduring-legacy |website=GamesIndustry.biz |publisher=[[Gamer Network]] |access-date=1 October 2023 |archive-url=https://web.archive.org/web/20221104151132/https://www.gamesindustry.biz/zx-spectrum-an-enduring-legacy |archive-date=4 November 2022 |location=[[Brighton]] |language=en |date=26 October 2017}}</ref> On 25 July 1961, three years after passing his [[GCE Advanced Level (United Kingdom)|A-level]]s, he founded [[Sinclair Radionics]] Ltd as a vehicle to advertise his inventions and buy components.{{sfn|Dale|1985|p=21}} In 1972, Sinclair had competed with [[Texas Instruments]] to produce the world's first [[pocket calculator]], the [[Sinclair Executive]].<ref name=newyork>{{cite web |last1=Bailey |first1=Elizabeth |title=Inventor; trying again in consumer electronics |url=https://www.nytimes.com/1981/04/12/business/inventor-trying-again-in-consumer-electronics.html |work=[[The New York Times]] |access-date=1 October 2023 |archive-url=https://web.archive.org/web/20230516222227/https://www.nytimes.com/1981/04/12/business/inventor-trying-again-in-consumer-electronics.html |archive-date=16 May 2023 |location=New York City |date=12 April 1981}}</ref> By the mid 1970s, Sinclair Radionics was producing handheld electronic calculators, miniature televisions, and the ill-fated digital [[Black Watch (wristwatch)|Black Watch]] wristwatch.{{sfn|Leigh|2022|pp=80-81}} Due to financial losses, Sinclair sought investors from the [[National Enterprise Board]] (NEB), who had bought a 43% interest in the company and streamlined his product line. Sinclair's relationship with the NEB had worsened, however, and by 1979 it opted to break up Sinclair Radionics entirely,{{sfn|Kean|1985b|p=126}} selling off its television division to [[Binatone]] and its calculator division to ESL Bristol.{{sfn|Dale|1985|pp=77-78}}

After incurring a £7 million investment loss, Sinclair was given a [[golden handshake]] and an estimated £10,000 severance package.<ref name=newyork/><ref>{{cite web |title=Sir Clive Sinclair obituary |url=https://www.thetimes.com/uk/obituaries/article/sir-clive-sinclair-obituary-jjgjq296k |work=[[The Times]] |access-date=1 October 2023  |location=London |language=en |date=1 October 2023 |url-status=live |archive-url= https://archive.today/20210916203447/https://www.thetimes.co.uk/article/sir-clive-sinclair-obituary-jjgjq296k |archive-date= 16 September 2021  }}</ref> He had a former employee, [[Christopher Curry (businessman)|Christopher Curry]], establish a "corporate lifeboat" company named Science of Cambridge Ltd, in July 1977, called such as they were located near the [[University of Cambridge]].{{sfn|Dale|1985|p=89}} By this time inexpensive [[microprocessor]]s had started appearing on the market, which prompted Sinclair to start producing the [[MK14]], a [[electronic kit|computer teaching kit]] which sold well at a very low price.{{sfn|Dale|1985|p=91}} Encouraged by this success, Sinclair renamed his company to [[Sinclair Research]], and started looking to manufacture personal computers. Keeping the cost low was essential for Sinclair to avoid his products from becoming outpriced by American or Japanese equivalents as had happened to several of the previous Sinclair Radionics products.<ref name=newyork/> On 29 January 1980, the [[ZX80]] home computer was launched to immediate popularity; notable for being one of the first computers available in the United Kingdom for less than £100.{{sfn|Laurie|1981|p=113}}{{sfn|Hayes|1981|p=119}} The company conducted no market research whatsoever prior to the launch of the ZX80; according to Sinclair, he "simply had a hunch" that the public was sufficiently interested to make such a project feasible and went ahead with ordering 100,000 sets of parts so that he could launch at high volume.<ref name="FT-noresearch">{{cite news| title = The precarious balance between research, fashion and price| last = Lorenz | first = Christopher| newspaper = [[Financial Times]]|location=London| page = 18| date = 15 April 1982}}</ref>

On 5 March 1981, the [[ZX81]] was launched worldwide to immense success with more than 1.5 million units sold,<ref name="Sinclair-Research">{{cite web| title = Sinclair ZX8| publisher = Sinclair Research| url = http://www.sinclairzx.com/about-us.html#12 | url-status = dead| archive-url = https://web.archive.org/web/20141214131822/http://www.sinclairzx.com/about-us.html#12| access-date = 5 January 2011 | archive-date = 14 December 2014}}</ref> 60% of which was outside Britain.{{sfn|Clarke|1982|p=390}} According to [[Ben Rosen]], by pricing the ZX81 so low, the company had "opened up a completely new market among people who had never previously considered owning a computer".{{sfn|Engineering Today|1982|pp=20–23}} After its release, computing in Britain became an activity for the general public rather than the preserve of office workers and hobbyists. The ZX81's commercial success made Sinclair Research one of Britain's leading computer manufacturers, with Sinclair himself reportedly "amused and gratified" by the attention the machine received.{{sfn|Hayman|1982|p=23}}

=== Development ===
[[File:ZX Spectrum concept.jpg|thumb|An original concept sketch of the ZX Spectrum, depicting an angular and wedge-like form similar to its predecessor, the [[ZX81]] ]]

Development of the ZX Spectrum began in September 1981, a few months after the release of the ZX81. Sinclair resolved to make his own products obsolete before his rivals developed the products that would do so. Parts of designs from the ZX80 and ZX81 were reused to ensure a speedy and cost-effective manufacturing process. The team consisted of 20 engineers housed in a small office at 6 [[King's Parade]], Cambridge.<ref name="edgehistory">{{cite magazine |last1=Brown |first1=Nathan |title=The making of the ZX Spectrum |url=http://www.edge-online.com/features/making-zx-spectrum/ |magazine=[[Edge (magazine)|Edge]] |publisher=[[Future plc]] |access-date=4 April 2021 |archive-url=https://web.archive.org/web/20120425035159/http://www.edge-online.com/features/making-zx-spectrum/ |archive-date=25 April 2012 |location=[[Bath, Somerset|Bath]] |date=23 April 2012}}</ref> During early production, the machine was known as the ZX81 Colour or the ZX82 to highlight the machine's colour display, which differed from the black and white of its predecessors. The addendum "Spectrum" was added later on, to emphasise its 15-colour palette.{{sfn|Leigh|2018|p=68}} Aside from a new [[crystal oscillator]] and extra chips to add additional [[kilobyte]]s of memory,{{sfn|Adams|1982|p=14}} the ZX Spectrum was intended to be, as quoted by Sinclair's marketing manager, essentially a "ZX81 with colour".<ref name=edgehistory/> According to Sinclair, the team also wanted to combine the ZX81's separate [[random-access memory]] sections for audio and video into a single bank.<ref name="registerlegacy">{{cite web |last1=Speed |first1=Richard |title=Sinclair's 8-bit home computer, ZX Spectrum, turns 40 |url=https://www.theregister.com/2022/04/22/spectrum_at_40/ |website=The Register |publisher=Situation Publishing |access-date=2 October 2023 |archive-url=https://web.archive.org/web/20230526232039/https://www.theregister.com/2022/04/22/spectrum_at_40/ |archive-date=26 May 2023 |location=London |language=en |date=22 April 2022}}</ref>

Chief engineer [[Richard Altwasser]] was responsible for the ZX Spectrum's hardware design. His main contribution was the design of the semi-custom [[Gate array|uncommitted logic array]] (ULA) integrated circuit, which integrated, on a single chip, the essential hardware functions. Altwasser designed a graphics mode that required less than 7 kilobytes of memory and implemented it on the ULA. Vickers wrote most of the ROM code. Lengthy discussions between Altwasser and Sinclair engineers resulted in a broad agreement that the ZX Spectrum must have high-resolution graphics, 16 kilobytes of memory, an improved [[Cassette tape#data|cassette interface]], and an impressive colour palette.{{sfn|Gore|1982|p=38}} To achieve this, the team had to divorce the [[central processing unit]] (CPU) away from the main display to enable it to work at full efficiency – a method which contrasted with the ZX81's integrated CPU.{{sfn|Gore|1982|p=38}} The inclusion of colour to the display proved a major obstacle to the engineers. A [[Teletext]]-like approach was briefly considered, in which each line of text would have colour-change codes inserted into it. However, this was ruled out, as it was deemed unsuitable for high-resolution graphs or diagrams that involved multiple colour changes. Altwasser devised the idea of allocating a [[BIOS color attributes|colour attribute]] to each character position on the screen. This ultimately used eight [[bit]]s of memory for each character position; three bits to provide any one of eight foreground colours and three bits for the eight [[Web colors|background colours]], one bit for extra brightness and one bit for flashing. Overall, the system took up slightly less than 7 kilobytes of memory, leaving an additional 9 kilobytes to write programs&nbsp;– a figure that pleased the team.{{sfn|Gore|1982|pp=38-39}}

Much of the firmware was written by computer scientist [[Steve Vickers (computer scientist)|Steve Vickers]] from Nine Tiles,<ref name="registerlegacy"/> who compiled all control routines to produce the [[Sinclair BASIC]] interpreter, a custom variant of the general purpose [[BASIC]] programming language. Making a custom interpreter made it possible to fit all of its functionality into a very small amount of [[read-only memory]] (ROM).{{sfn|Adams|1982|p=14}} The development process of the software was marked by disagreements between Nine Tiles and Sinclair Research. Sinclair placed an emphasis on expediting the release of the Spectrum, primarily by minimising alterations in the software from the ZX81, which had in turn been based on the ZX80's software. The software architecture of the ZX80, however, had been tailored for a severely constrained memory system, and in Nine Tiles' opinion was unsuitable for the enhanced processing demands of the ZX Spectrum. Sinclair favoured solving this with expansion modules on the existing framework like with the ZX81, which Nine Tiles disagreed with. Ultimately, both designs were developed, but Vickers and Nine Tiles were unable to finish their version before the launch of the Spectrum and it was not used.{{sfn|Adamson|Kennedy|1986|pp=84-88}}

[[File:Rick Dickinson.jpg|thumb|left|Designer [[Rick Dickinson]] in the [[Sinclair Research]] Cambridge office in 1983]]
The distinctive case and colourful design of the ZX Spectrum was the creation of [[Rick Dickinson]], a young British industrial designer who had been hired by Sinclair to design the ZX81. Dickinson was tasked to design a sleeker and more "marketable" appearance to the new machine, whilst ensuring all 192 BASIC functions could fit onto 40 physical keys.<ref name=edgehistory/> Early sketches from August 1981 showed the case was to be more angular and wedge-like, in similar vein to an upgraded ZX81 model. Dickinson later settled on a flatter design with a raised rear section and rounded sides in order to depict the machine as "more advanced" as opposed to a mere upgrade. In drawing up potential logos, Dickinson proposed a series of different logotypes which all featured rainbow slashes across the keyboard.<ref name=registerhistory/>

The design of the Spectrum's [[Chiclet keyboard|rubber keyboard]] was simplified from several hundred components to a conventional moving keyboard down to "four to five" moving parts using a new technology.<ref name="bbc30">{{cite web |last1=Kelion |first1=Leo |title=ZX Spectrum's chief designers reunited 30 years on |url=https://www.bbc.co.uk/news/technology-17776666 |website=[[BBC News]] |publisher=[[BBC]] |access-date=2 October 2023 |archive-url=https://web.archive.org/web/20230418150809/https://www.bbc.co.uk/news/technology-17776666 |archive-date=18 April 2023 |location=London |date=19 April 2012}}</ref> The keyboard was still undergoing changes as late as February 1982; some sketches included a roundel-on-square key design which was later featured on the later Spectrum+ model.<ref name=registerhistory/> Dickinson recalled in 2007 that "everything was cost driven" and that the minimalist, [[Bauhaus]] approach to the Spectrum gave it an elegant yet "[non] revolutionary" form.<ref name=bbclegacy/> The drawing board on which Dickinson designed the ZX Spectrum is now on display in the [[Science Museum, London|Science Museum]] in London.<ref>{{cite web |title=Sinclair Spectrum designer Rick Dickinson dies in US |url=https://www.bbc.co.uk/news/technology-43907248 |website=[[BBC News]] |publisher=[[BBC]] |archive-url=https://web.archive.org/web/20230930220700/https://www.bbc.co.uk/news/technology-43907248 |archive-date=30 September 2023 |location=London |date=26 April 2018}}</ref><ref>{{cite web |title=Alpia drawing board - Science Museum Group Collection |url=https://collection.sciencemuseumgroup.org.uk/objects/co8087251/alpia-drawing-board-used-by-rick-dickinson-to-des-drawing-board |publisher=The Science Museum Group |access-date=9 October 2023 |archive-url=https://web.archive.org/web/20221129031620/https://collection.sciencemuseumgroup.org.uk/objects/co8087251/alpia-drawing-board-used-by-rick-dickinson-to-des-drawing-board |archive-date=29 November 2022 |location=London |language=en}}</ref>

The need for an improved cassette interface was apparent from the number of complaints received from ZX81 users, who encountered problems when trying to save and load programs.{{sfn|Gore|1982|p=39}} To increase the data transfer speed, the team significantly decreased the length of tones that represent binary data.{{sfn|Gore|1982|p=39}} To increase the reliability, a leading period of [[pure tone|constant tone]] was introduced, which allowed the cassette recorder's [[automatic gain control]] to settle itself down, eliminating hisses on the tape.{{sfn|Gore|1982|p=39}} A [[Schmitt trigger]] was added inside the ULA to reduce noise of the received signal.{{sfn|Gore|1982|p=39}} Originally, the team aimed for data transfer speed of 1000 [[baud]], but succeeded in getting it to work at a considerably faster 1500 baud.{{sfn|Gore|1982|p=39}} Unlike the ZX81, the Spectrum was able to maintain its display during loading and saving operations, and programmers took advantage of this to show a [[splash screen]] whilst loading took place in the background.

As with the ZX81, the ZX Spectrum was manufactured in [[Dundee]], Scotland, by [[Timex Group USA|Timex Corporation]] at the company's [[Dryburgh, Dundee district|Dryburgh]] factory.<ref name="Day">{{cite news|last1=Day|first1=Peter|title=How Dundee became a computer games centre|work=[[BBC News]]|location=London|date=9 September 2014|url=https://www.bbc.co.uk/news/business-29122873|access-date=12 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161009014928/http://www.bbc.co.uk/news/business-29122873|archive-date=9 October 2016}}</ref><ref>{{cite web |title=ZX Spectrum Computer and associated game cassettes |url=https://www.themcmanus-dundee.gov.uk/content/collections/database/zx-spectrum-computer-and-associated-game-cassettes |website=The McManus |publisher=Dundee Art Gallery |access-date=3 October 2023 |archive-url=https://web.archive.org/web/20231003134524/https://www.themcmanus-dundee.gov.uk/content/collections/database/zx-spectrum-computer-and-associated-game-cassettes |archive-date=3 October 2023 |location=[[Dundee]] |language=English |date=20 January 2012}}</ref> Prior to the manufacture of the ZX81, however, Timex had little experience in assembling electronics and had not originally been an obvious choice of manufacturing subcontractor. It was a well-established manufacturer of mechanical watches but was facing a crisis at the beginning of the 1980s; profits had dwindled to virtually zero as the market for watches stagnated in the face of competition from the [[Watch#Digital|digital]] and [[Quartz clock|quartz watches]]. Recognising the trend, Timex's director, [[Fredrik Olsen|Fred Olsen]], determined that the company would diversify into other areas and signed a contract with Sinclair.{{sfn|Adamson|Kennedy|1986|p=94}}

=== Launch ===
The ZX Spectrum was officially revealed before journalists by Sinclair at the [[Hyatt Regency London – The Churchill|Churchill Hotel]] in [[Marylebone]], London, on 23 April 1982.<ref name="registerhistory">{{cite web |last1=Smith |first1=Tony |title=Happy 30th Birthday, Sinclair ZX Spectrum |url=https://www.theregister.com/2012/04/23/retro_week_sinclair_zx_spectrum_at_30?page=1 |website=The Register |access-date=2 October 2023 |archive-url=https://web.archive.org/web/20231002185823/https://www.theregister.com/2012/04/23/retro_week_sinclair_zx_spectrum_at_30?page=1 |archive-date=2 October 2023 |language=en |date=23 April 2012|url-status=live}}</ref><ref name="autogenerated1">{{Cite news | last = Warman | first = Matt | date = 23 April 2012 | title = ZX Spectrum at 30: the computer that started a revolution | newspaper = [[The Daily Telegraph]] | url = https://www.telegraph.co.uk/technology/news/9220468/ZX-Spectrum-at-30-the-computer-that-started-a-revolution.html | location = London | archive-url = https://web.archive.org/web/20130308205705/http://www.telegraph.co.uk/technology/news/9220468/ZX-Spectrum-at-30-the-computer-that-started-a-revolution.html | archive-date = 8 March 2013 | url-status = live | access-date = 31 March 2015 | quote = It was the computer that introduced a generation to video gaming, helped to earn Sir Clive Sinclair a knighthood and even made programming cool: the ZX Spectrum has a lot to answer for. }}</ref> Later that week, the machine was officially presented in a "blaze of publicity" at the [[Earl's Court]] Computer Show in London,<ref>{{cite web |title=ZX Spectrum profile |url=https://www.retrogamer.net/profiles/hardware/zx-spectrum-hardware-profile/ |website=[[Retro Gamer]] |publisher=[[Future plc]] |access-date=3 October 2023 |archive-url=https://web.archive.org/web/20221215164112/https://www.retrogamer.net/profiles/hardware/zx-spectrum-hardware-profile/ |archive-date=15 December 2022 |location=[[Bath, Somerset|Bath]] |date=4 December 2013}}</ref>{{sfn|Adams|1982|p=52}} and the ZX Microfair in [[Manchester]].{{sfn|Clark|1982|p=4}} The ZX Spectrum was launched with two models: a 16KB 'basic' version, and an enhanced 48KB variant.{{sfn|Leigh|2018|p=69}} The former model had an undercutting price of £125, significantly lower than its main competitor the [[BBC Micro]], whilst the latter model's price of £175 was comparable to a third of an [[Apple II]] computer.{{sfn|Clark|1982|p=14}}{{sfn|Kean|1985b|p=127}} Upon release, the keyboard surprised many users due to its use of rubber keys, described as offering the feel of "dead flesh".<ref name=registerhistory/><ref name="telegraph">{{cite web |title=Sir Clive Sinclair, inventor of an early pocket calculator who transformed the home-computing market but came unstuck with the infamous C5 – obituary |url=https://www.telegraph.co.uk/obituaries/2021/09/16/sir-clive-sinclair-inventor-early-pocket-calculator-transformed/ |publisher=[[The Daily Telegraph|The Telegraph]] |access-date=3 October 2023 |archive-url=https://web.archive.org/web/20221118063318/https://www.telegraph.co.uk/obituaries/2021/09/16/sir-clive-sinclair-inventor-early-pocket-calculator-transformed/ |archive-date=18 November 2022 |location=London |date=16 September 2021}}</ref> Sinclair himself remarked that the keyboard's rubber mould was "unusual", but consumers were undeterred.<ref name=syntax/>

[[File:Harold Macmillan and Clive Sinclair.png|thumb|left|90 year-old [[Harold Macmillan]] using the ZX Spectrum with Sinclair looking on (1984)]]

Despite very high demand, Sinclair Research was "notoriously late" in delivering the ZX Spectrum. Their practice of offering mail-order sales before units were ready ensured a constant cash flow, but meant a lacking distribution.{{sfn|Leigh|2018|p=68}} [[Nigel Searle]], the newly-appointed chief of Sinclair's computer division, said in June 1982 the company had no plans to stock the new machine in [[WHSmith]], which was at the time Sinclair's only retailer.{{sfn|Clark|1982|p=43}} Searle explained that the mail-order system was in place due to there being no "obvious" retail outlets in the United Kingdom which could sell personal computers, and it made "better sense" financially to continue selling through mail-order.{{sfn|Clark|1982|p=44}} The company's conservative approach to distributing the machine was criticised,{{sfn|Leigh|2018|p=68}} with disillusioned customers telephoning and writing letters.{{sfn|Johnston|1982|p=4}}{{sfn|Pratt|1982a|p=4}} Demand sky-rocketed beyond Sinclair's planned 20,000 monthly unit output to a backlog of 30,000 orders by July 1982. Due to a scheduled holiday at the Timex factory that summer, the backlog had risen to 40,000 units. Sinclair issued a public apology in September that year,<ref name=registerhistory/> and promised that the backlog would be cleared by the end of that month.{{sfn|Johnston|1982|p=4}} Supply did not return to normal until the 1982 Christmas season, however.{{sfn|Leigh|2018|p=70}}

Production of the machine rapidly increased with the arrival of the less expensive Issue 2 [[motherboard]], a redesign of the main circuit board which addressed hardware manufacturing defects that affected production of the first model.{{sfn|Adamson|Kennedy|1986|p=256}} Sales of the ZX Spectrum reached 200,000 in its first nine months,{{sfn|Popular Computing Weekly|1983a|p=1}} rising to 300,000 for the whole of the first year.{{sfn|Backhurst|1983b|p=14}} By August 1983 total sales in Britain and Europe had exceeded 500,000,{{sfn|Popular Computing Weekly|1983c|p=1}} with the millionth Spectrum manufactured on 9 December 1983. By this point, an average of 50,000 units were being purchased each month.{{sfn|Popular Computing Weekly|1983d|p=5}}

In July 1983, an enhanced version of the ZX Spectrum was launched in the United States as the [[Timex Sinclair 2068]]. Advertisements described it as offering 72 kilobytes of memory, having a full range of colour and sound for a price under $200.<ref name="byte198312">{{cite news | url=https://archive.org/stream/byte-magazine-1983-12/1983_12_BYTE_08-12_Easy_Software#page/n281/mode/2up | title=Now from Timex...a powerful new computer. | work=BYTE | date=December 1983 | accessdate=20 October 2013 | author=Advertisement | pages=281}}</ref> Despite the improvements upon its British counterpart, sales proved poor and [[Timex Sinclair]] collapsed the following year.<ref name=registerhistory/>{{sfn|Bradbeer|1983|p=83}}<ref>{{cite web |title=Timex Sinclair 2068 - RTO - Computer - Computing History |url=https://www.computinghistory.org.uk/det/62128/Timex-Sinclair-2068-RTO/ |publisher=The Centre for Computing History |access-date=23 April 2024 |archive-url=https://web.archive.org/web/20240423204916/https://www.computinghistory.org.uk/det/62128/Timex-Sinclair-2068-RTO/ |archive-date=23 April 2024 |url-status=live}}</ref>

=== Success and market domination ===
[[File:Micro-computer wordt uitgeleend bij biobliotheek, bij wizej van experiment, Bestanddeelnr 933-0448 (colour).jpg|thumb|right|A woman is loaned a ZX Spectrum from a library in the Netherlands, 1984.]]
A crucial part of the company's marketing strategy was to implement regular price-cutting at strategic intervals to maintain [[market share]]. Ian Adamson and Richard Kennedy noted that Sinclair's method was driven by securing his leading position through "panicking" the competition. While most companies at the time reduced prices of their products while their market share was dwindling, Sinclair Research discounted theirs shortly after sales had peaked, throwing the competition into "utter disarray".{{sfn|Adamson|Kennedy|1986|p=143}} Sinclair Research made a profit of £14 million in 1983, compared to £8.5 million the previous year. [[Asset turnover|Turnover]] doubled from £27.2 million to £54.5 million, which equated to roughly £1 million for each person employed directly by the company.{{sfn|Segre|1983|p=18}}

Clive Sinclair became a focal point during the ZX Spectrum's marketing campaign by putting a human face onto the business. Sinclair Research was portrayed in the media as a "plucky" British challenger taking on the technical and marketing might of giant American and Japanese corporations. As David O'Reilly noted in 1986, "by astute use of public relations, particularly playing up his image of a Briton taking on the world, Sinclair has become the best-known name in micros."{{sfn|Adamson|Kennedy|1986|p=98}} The media latched onto Sinclair's image; his "Uncle Clive" persona is said to have been created by the gossip columnist for ''[[Personal Computer World]]''.{{sfn|Adamson|Kennedy|1986|p=97}} The press praised Sinclair as a visionary genius, with ''[[The Sun (United Kingdom)|The Sun]]'' lauding him as "the most prodigious inventor since [[Leonardo da Vinci]]". Adamson and Kennedy wrote that Sinclair outgrew the role of microcomputer manufacturer and "accepted the mantle of pioneering [[boffin]] leading Britain into a technological utopia".{{sfn|Adamson|Kennedy|1986|p=114}} Sinclair's contribution to the technology sector resulted in him being [[Knight Bachelor|knighted]] upon the recommendation of [[Margaret Thatcher]] in the [[1983 Birthday Honours|Queen's 1983 Birthday Honours List]].<ref name="bbctwo">{{cite web |title=Sir Clive Sinclair: Tireless inventor ahead of his time |url=https://www.bbc.co.uk/news/science-environment-29985976 |website=[[BBC News]] |access-date=18 October 2023 |archive-url=https://web.archive.org/web/20230518164253/https://www.bbc.co.uk/news/science-environment-29985976 |archive-date=18 May 2023 |location=London |date=16 September 2021}}</ref><ref name=mensabio>{{cite web |url=http://www.mensa.org.uk/cgi-bin/item.cgi?ap=1&id=279 |title=Biography of Sir Clive Sinclair |access-date=25 September 2007 |last=Goodenough |first=Jan |date=March 2000 |publisher=[[Mensa International|British Mensa]] |url-status=dead |archive-url=https://web.archive.org/web/20080202182911/http://www.mensa.org.uk/cgi-bin/item.cgi?ap=1&id=279 |archive-date=2 February 2008}}</ref><ref>{{cite web |last1=Bates |first1=Stephen |title=Sir Clive Sinclair obituary |url=https://www.theguardian.com/technology/2021/sep/17/sir-clive-sinclair |work=[[The Guardian]] |access-date=3 October 2023 |archive-url=https://web.archive.org/web/20230326032914/https://www.theguardian.com/technology/2021/sep/17/sir-clive-sinclair |archive-date=26 March 2023 |location=London |date=17 September 2021}}</ref>

The United Kingdom was largely immunised from the effects of the [[video game crash of 1983]], due to the saturation of home computers such as the ZX Spectrum.{{sfn|Leigh|2018|p=104}}<ref>{{cite web | url = https://www.ign.com/articles/2011/09/21/ten-facts-about-the-great-video-game-crash-of-83 | title = Ten Facts about the Great Video Game Crash of '83 | first = Nadia | last = Oxford | date = 18 January 2012 | access-date = 11 September 2020 | work = [[IGN]] | archive-date = 28 January 2021 | archive-url = https://web.archive.org/web/20210128072326/https://www.ign.com/articles/2011/09/21/ten-facts-about-the-great-video-game-crash-of-83 | url-status = live }}</ref><ref name="nerd">{{cite web |last1=Leigh |first1=Peter |title=ZX Spectrum Story: Celebrating 35 Years of the Speccy |url=https://www.nostalgianerd.com/zx-spectrum-story/ |publisher=Nostalgia Nerd |access-date=23 October 2023 |archive-url=https://web.archive.org/web/20230804184058/https://www.nostalgianerd.com/zx-spectrum-story/ |archive-date=4 August 2023 |date=21 April 2017}}</ref> The microcomputer market continued to grow and game development was unhindered despite the turbulence in the American markets. Indeed, computer games remained the dominant sector of the British home video game market up until they were surpassed by [[Sega]] and [[Nintendo]] consoles in 1991.{{sfn|His Majesty's Stationery Office|1995|pp=[https://i.imgur.com/CLYiKIp.jpg 66], [https://i.imgur.com/vR9vtPX.jpg 68]}} By the end of 1983 there were more than 450 companies in Britain selling video games on cassette, compared to 95 the year before.<ref name="wired uk history">{{cite magazine | url = https://www.wired.com/2010/06/sinclair-zx80/ | title = Sinclair ZX80 and the Dawn of 'Surreal' U.K. Game Industry | first = Chris | last = Baker | date = 6 August 2010 | access-date = 30 September 2019 | magazine = [[Wired (magazine)|Wired]] | archive-date = 26 July 2019 | archive-url = https://web.archive.org/web/20190726200228/https://www.wired.com/2010/06/sinclair-zx80/ | url-status = live }}</ref> An estimated 10,000 to 50,000 people, mostly young men, were developing games out of their homes based on advertisements in popular magazines. The growth of video games during this period has been compared to the [[punk subculture]], fuelled by young people making money from their games.<ref name="independent origins">{{cite web | url = https://www.independent.co.uk/life-style/gadgets-and-tech/features/geeks-who-rocked-the-world-documentary-looks-back-at-origins-of-the-computer-games-industry-9997037.html | title = Geeks Who Rocked The World: Documentary Looks Back At Origins Of The Computer-games Industry | first = Rhordi | last = Mardsen | date = 25 January 2015 | access-date = 3 October 2019 | work = [[The Independent]] | archive-date = 9 November 2019 | archive-url = https://web.archive.org/web/20191109005014/https://www.independent.co.uk/life-style/gadgets-and-tech/features/geeks-who-rocked-the-world-documentary-looks-back-at-origins-of-the-computer-games-industry-9997037.html | url-status = live }}</ref>

By the mid 1980s, Sinclair Research's share of the British home computer market had climbed to a high of 40 per cent.<ref name=newyorkdeal/> Sales in the 1984 Christmas season were described as "extremely good".{{sfn|Bourne|1985a|p=7}} In early 1985 the British press reported the home computer boom to have ended,<ref>{{cite web |title=The 80s home computer boom (video) |url=https://www.bbc.co.uk/programmes/p0336d72 |website=[[BBC Radio 4]] |publisher=[[BBC]] |access-date=24 October 2023 |archive-url=https://web.archive.org/web/20150926051715/https://www.bbc.co.uk/programmes/p0336d72 |archive-date=26 September 2015 |location=London |date=22 September 2015 |url-status=live}}</ref> leaving many companies slashing prices of their hardware to anticipate lower sales.{{sfn|Bourne|1985a|p=7}} Despite this, celebration of Sinclair's success in the computing market continued at the ''[[Which?|Which Computer?]]'' show in [[Birmingham]], where the five-millionth Sinclair machine (a gold coloured QL) was issued as a prize.{{sfn|Bourne|1985a|p=7}}

=== Later years and company decline ===
[[File:Sinclair sale to Amstrad 1986 Sinclair Sugar handshake.jpg|thumb|Sinclair shaking hands with [[Alan Sugar]], to mark the conclusion of the sale to [[Amstrad]] in 1986]]
The ZX Spectrum's successor, the [[Sinclair QL]], was officially announced on 12 January 1984, shortly before the [[Macintosh 128K]] went on sale.{{sfn|Denham|1984a|p=4}} Contrasting with its predecessors, the QL was aimed at more serious, professional home users.{{sfn|Sawford|1984|p=47}} It suffered from several design flaws; fully operational QLs were not available until the late summer, and complaints against Sinclair concerning delays were upheld by the [[Advertising Standards Authority (United Kingdom)|Advertising Standards Authority]] (ASA) in May of that year. Particularly serious were allegations that Sinclair was cashing cheques months before machines were shipped. By autumn 1984, Sinclair was still publicly forecasting that it would be a "million seller" and that 250,000 units would be sold by the end of the year.{{sfn|Munford|1984|p=72}} QL production was suspended in February 1985, and the price was halved by the end of the year.<ref name="Timex/Sinclair history">{{cite web|url=http://www.zqaonline.com/Events/History.aspx|title=Timex/Sinclair history|work=ZQAOnline|access-date=15 December 2006|url-status=dead|archive-url=https://web.archive.org/web/20060717042421/http://www.zqaonline.com/Events/History.aspx|archive-date=17 July 2006}}</ref> It ultimately flopped, with 139,454 units being manufactured.<ref>{{cite web |last1=Smith |first1=Tony |title=Sinclair's 1984 big shot at business: The QL is 30 years old |url=https://www.theregister.com/2014/01/12/archaeologic_sinclair_ql/?page=2 |website=[[The Register]] |publisher=Situation Publishing |access-date=26 October 2023 |archive-url=https://web.archive.org/web/20221212112255/https://www.theregister.com/2014/01/12/archaeologic_sinclair_ql/?page=2 |archive-date=12 December 2022 |location=London |language=en}}</ref>

The ZX Spectrum+, a rebranded ZX Spectrum with identical technical specifications except for the QL-like keyboard, was introduced in October 1984 and made available in WHSmith's stores the day after its launch. Retailers stocked the device in high quantities, anticipating robust Christmas sales. Nevertheless, the product did not perform as well as projected, leading to a significant drop in Sinclair's income from orders in January, as retailers were left with surplus stock. Subsequently, an upgraded model, the ZX Spectrum 128, was released in Spain in September 1985, with development financed by the Spanish distributor Investrónica.<ref name="Kept in the Dark">{{cite magazine | date = November 1985 | title = Kept in the Dark | magazine = [[Crash (magazine)|CRASH]] | issue = 22 | url = http://www.crashonline.org.uk/22/editrl.htm | access-date = 15 December 2006 | archive-date = 14 May 2011 | archive-url = https://web.archive.org/web/20110514040006/http://www.crashonline.org.uk/22/editrl.htm | url-status = live }}</ref> The launch of this model in the UK was postponed until January 1986 due to the substantial leftover inventory of the prior model.<ref name="comphist-spec128">{{cite web|url=http://www.computinghistory.org.uk/cgi-bin/sitewise.pl?act=det&p=2584|title=Sinclair ZX Spectrum 128|publisher=The Centre for Computing History|access-date=4 December 2009|archive-date=21 August 2010|archive-url=https://web.archive.org/web/20100821130000/http://www.computinghistory.org.uk/cgi-bin/sitewise.pl?act=det&p=2584|url-status=live}}</ref>

While the Sinclair QL was in development, Sinclair also hoped to repeat his success with the Spectrum in the fledgling electric vehicle market, which he saw as ripe for a new approach. On 10 January 1985, Sinclair unveiled the [[Sinclair C5]], a small one-person [[battery electric vehicle|battery electric]] [[Recumbent bicycle|recumbent]] [[tricycle]]. It marked the culmination of Sir Clive's long-running interest in electric vehicles.{{sfn|Dale|1985|p=151}} The C5 turned out to be a significant commercial failure, selling only 17,000 units and losing Sinclair £7 million. It has since been described as "one of the great marketing bombs of postwar British industry".{{sfn|Fraser|1986|p=14}} The ASA ordered Sinclair to withdraw advertisements for the C5 after finding that the company's claims about its safety could not be proved or justified.<ref>{{cite news|title=C5 advert claims rejected|date=17 July 1985|work=[[The Times]]|publisher=[[News Corp]]|location=London|page=3}}</ref>

The combined failures of the C5 and QL caused investors to lose confidence in Sinclair's judgement. In May 1985, Sinclair Research announced their intention to raise an additional £10 to £15 million to restructure the organisation. Given the loss of confidence in the company, securing the funds proved to be a challenging task. In June 1985, business magnate [[Robert Maxwell]] disclosed a takeover bid for Sinclair Research through Hollis Brothers, a subsidiary of his [[Pergamon Press]].<ref name="nyt-srl">{{cite news|url=https://www.nytimes.com/1985/06/18/business/sinclair-to-sell-british-unit.html|title=Sinclair to Sell British Unit|date=18 June 1985|work=[[The New York Times]]|agency=[[Associated Press]]|url-access=limited|access-date=4 December 2009|archive-date=18 May 2013|archive-url=https://web.archive.org/web/20130518140601/http://www.nytimes.com/1985/06/18/business/sinclair-to-sell-british-unit.html|url-status=live}}</ref> However, the deal was terminated in August 1985.<ref name="newyorkdeal">{{cite news |title=Hollis pulls out of Sinclair offer |url=https://www.nytimes.com/1985/08/10/business/hollis-pulls-out-of-sinclair-offer.html |access-date=19 October 2023 |work=[[The New York Times]] |date=10 August 1985 |archive-url=https://web.archive.org/web/20230516175942/https://www.nytimes.com/1985/08/10/business/hollis-pulls-out-of-sinclair-offer.html |archive-date=16 May 2023 |location=New York City |page=32}}</ref> The future of Sinclair Research remained uncertain until 7 April 1986, when the company sold their entire computer product range, along with the "Sinclair" brand name, to [[Alan Sugar]]'s [[Amstrad]] for £5 million.{{sfn|Kidd|1986|p=7}} The takeover sent ripples through the [[London Stock Exchange]], but Amstrad's shares soon recovered, with one stock broker affirming that "[[City of London|the City]] appears to have taken the news in its stride".{{sfn|Scolding|1986|p=7}} Amstrad's acquisition of the brand name saw the release of three ZX Spectrum models throughout the late 1980s, each with varying improvements.{{sfn|Phillips|1986|p=47}}

By 1990, Sinclair Research consisted of Sinclair and two other employees down from 130 employees at its peak in 1985.<ref>{{cite web | url = https://www.nytimes.com/1985/05/19/magazine/inventing-the-future.html | title = Inventing the Future | first = Barnaby | last = Feder | date = 19 May 1985 | accessdate = 18 September 2021 | work = [[The New York Times]]|location=New York City|archiveurl=https://web.archive.org/web/20230516193313/https://www.nytimes.com/1985/05/19/magazine/inventing-the-future.html|archivedate=16 May 2023}}</ref> The ZX Spectrum was officially discontinued in 1992, after ten years on the market.{{sfn|Leigh|2018|p=70}}<ref name="bbclegacy" /> Sinclair Research continued to exist as a one-man company, marketing Sir Clive Sinclair's inventions until his death in September 2021.