Sinclair Research Ltd is a British consumer electronics company founded by Clive Sinclair in Cambridge. It was incorporated in 1973 as Westminster Mail Order Ltd, renamed Sinclair Instrument Ltd Science of Cambridge Ltd Sinclair Computers Ltd, Sinclair Research Ltd, it remained dormant until 1976, when it was activated with the intention of continuing Sinclair's commercial work from his earlier company Sinclair Radionics, adopted the name Sinclair Research in 1981. In 1980, Clive Sinclair entered the home computer market with the ZX80 at £99.95, at that time the cheapest personal computer for sale in the United Kingdom. In 1982 the ZX Spectrum was released, becoming the UK's best selling computer, competing aggressively against Commodore and Amstrad. At the height of its success, inspired by the Japanese Fifth Generation Computer program, the company established the "MetaLab" research centre at Milton Hall near Cambridge, in order to pursue artificial intelligence, wafer-scale integration, formal verification and other advanced projects.
A combination of the failures of the Sinclair QL computer and the TV80 led to financial difficulties in 1985, a year Sinclair sold the rights to its computer products and brand name to Amstrad. Sinclair Research Ltd still exists as a one-man company, continuing to market Clive Sinclair's inventions. On 25 July 1961, Clive Sinclair founded Sinclair Radionics Ltd. in Cambridge. The company developed hi-fi products, radios and scientific instruments; when it became clear that Radionics was failing, Sinclair took steps to ensure that he would be able to continue to pursue his commercial goals. In February 1975, he changed the name of Ablesdeal Ltd to Westminster Mail Order Ltd; the name was changed to Sinclair Instrument Ltd in August 1975. Finding it inconvenient to share control after the National Enterprise Board became involved in Radionics in 1976, Sinclair encouraged Chris Curry to leave Radionics, which he had worked for since 1966, get Sinclair Instrument operational; the company's first product was a watch-like Wrist Calculator.
In July 1977, Sinclair Instrument Ltd was renamed Science of Cambridge Ltd. Around the same time, Ian Williamson showed Chris Curry a prototype microcomputer based on a National Semiconductor SC/MP microprocessor and parts from a Sinclair calculator. Curry was encouraged Sinclair to adopt it as a product. In June 1978, Science of Cambridge launched its MK14 microcomputer in kit form. In May 1979, Jim Westwood, Sinclair's chief engineer, designed a new microcomputer based on the Zilog Z80 microprocessor. Sinclair Instrument Ltd introduced the computer as the ZX80 in February 1980, as both a kit and ready-built. In November 1979, Science of Cambridge Ltd was renamed Sinclair Computers Ltd. In March 1981, Sinclair Computers was renamed Sinclair Research Ltd and the Sinclair ZX81 was launched. In February 1982, Timex Corporation obtained a license to manufacture and market Sinclair's computers in the USA under the name Timex Sinclair. In April the ZX Spectrum was launched. In July Timex launched the TS 1000 in the United States.
In March 1982 Sinclair Research Ltd made an £8.55m profit on turnover of £27.17m, including a £383,000 government grant to develop a flat screen. In 1982 Clive Sinclair converted the Barker & Wadsworth mineral water bottling factory at 25 Willis Road, into the company's new headquarters. In January 1983 the ZX Spectrum personal computer was presented at the Las Vegas Consumer Electronics Show. In September the Sinclair TV80 pocket television was launched, but was a commercial failure. In 1983 the company bought Milton Hall in the village of Milton, for £2m, establishing its MetaLab research and development facility there. In late 1983 Timex decided to pull out of the Timex Sinclair venture which, due to strong competition, had failed to break into the United States market. However, Timex computers continued to be produced for several years in other countries. Timex Portugal launched improved versions, the TS 2048 and 2068; the Sinclair QL was announced on 12 January 1984. The QL was nowhere near as successful as Sinclair's earlier computers.
It suffered from several design flaws, Your Sinclair noted that it was "difficult to find a good word for Sinclair Research in the computer press". Working QLs were not available until late summer and complaints against Sinclair regarding delays were upheld by the Advertising Standards Authority in May of that year. Severe were allegations that Sinclair was cashing cheques months before machines were shipped. In the autumn Sinclair was still publicly predicting it would be a "million seller", that 250,000 would be sold by the end of the year. QL production was suspended in February 1985, the price was halved by the end of the year; the ZX Spectrum+, a repackaged ZX Spectrum with a QL-like keyboard, was launched in October 1984 and appeared in WHSmith's shops the day after release. Retailers stocked the machine in large numbers in expectation of good Christmas sales. However, the machine did not sell as well as expected and, because retailers still had unsold stock, Sinclair's income from orders dipped alarmingly in January.
The Spectrum+ had the same technical specifications as the original Spectrum. An enhanced model, the ZX Spectrum 128, was
Timex Computer 2048
This article is about the Timex Computer 2048. For the named but different ZX Spectrum-variant prototype intended for sale in North America, see Timex Sinclair 2048; the TC-2048 or Timex Computer 2048 is a 1984 computer created by "Timex North American, Lda", a branch of Timex Corporation. It was based on the Timex Sinclair 2048 prototype, a 16k version of the TS-2068, with a similar redesign case, Kempston joystick interface and additional video modes, it was compatible with the Sinclair ZX Spectrum computer, although differences in the ROM prevented 100% compatibility. Timex Portugal sold the TC 2048 in Portugal and Poland, where it was successful, selling more than 10000 units. A NTSC version was sold in Chile; this computer forms the basis of an improved Spectrum-compatible machine, the Spectrum SE. Two modifications of the TC2048 exist: the TC2128 and the TC2144. Both upgrade the ULA to use four screen areas. CPU Zilog Z80A @ 3.50 MHzROM 16 KBRAM 48 KBDisplay Improved ULA offering additional screen modes: Text: 32×24 characters Graphics: 256×192 pixels, 15 colours Extended Color: 256×192 pixels, 15 colors with colour resolution of 32×192 Dual Screen: A monochrome 512×192 modeSound Beeper I/O Z80 bus in/out Line audio in/out for external cassette tape storage RF television out Composite video monitor out Kempston Joystick inputStorage External cassette tape recorder 1–8 external ZX Microdrives Timex FDD Timex FDD3000 Timex Sinclair Timex Sinclair 2068 Timex Computer World
The Dubna 48K is a Soviet clone of the ZX Spectrum home computer. It was based on an analogue of the Zilog Z80 microprocessor, its name comes from Dubna, a town near Moscow where it was produced, "48K" stands for 48 KBs of RAM. According to the manual, this computer was intended for: studying the principles of PC operation various kinds of calculations "intellectual games"By the time this computer was released, there were much more powerful x86 CPUs and commercially available advanced operating systems, such as Unix, DOS and Windows; the Dubna 48K had only a built-in BASIC interpreter, loaded its programs from a cassette recorder, so it couldn't run any of the modern operating systems, as such, wasn't suitable for "studying the principles of PC operation". However, the Dubna 48K and many other Z80 clones, hopelessly outdated by that time, were introduced in high schools of the Soviet Union. Many of the games for the Z80-based machine were ported from games available for Nintendo's 8-bit game console, marketed in Russia under the brand Dendy.
The Dubna 48K was shipped with the following units: Main unit, with mainboard and built-in keyboard External power unit Video adapter for connecting the computer to the TV set BASIC programming manual Reference book, including complete schematic circuitAdditionally, there were some optional items: Joystick 32 cm colour monitorThe computer could connect to a ZX Microdrive, but such device was never included. CPU: 8-bit MME 80A, 1.875 MHz running at half speed of the original ZX Spectrum RAM: 48 KB ROM: 16 KB Resolution: 192×256 pixels, or 24 rows of 32 characters each Number of colours: 8 colours in either normal or bright mode, which gives 15 shades Power unit: 5V, 1.7 A Dimensions of main unit: 47×320×240 mm A device named Dubna 48K is referenced in the American film Jason Bourne. In the film, rogue agent Nicky Parsons uses a "palm-sized authentication device" named Dubna 48K to get connected to the mainframe computer of the Central Intelligence Agency. Parsons downloads all the files on the Agency's black operations.
The Agency finds out that the Dubna 48K unit was destroyed back in 1993, its access to the mainframe was never revoked. The Agency did not know that it had survived its reported destruction; the film does not explain how a device from the 1990s could be still compatible with a mainframe computer of the 2010s. The film does not point out that the real Dubna 48K was a Soviet home computer, used to play ports of video games; the video games available to the real Dubna 48K were released by Nintendo and were products of the third generation of video game consoles
IBM Personal Computer
The IBM Personal Computer known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, was introduced on August 12, 1981, it was created by a team of engineers and designers under the direction of Don Estridge of the IBM Entry Systems Division in Boca Raton, Florida. The generic term "personal computer" was in use years before 1981, applied as early as 1972 to the Xerox PARC's Alto, but because of the success of the IBM Personal Computer, the term "PC" came to mean more a desktop microcomputer compatible with IBM's Personal Computer branded products. Since the machine was based on open architecture, within a short time of its introduction, third-party suppliers of peripheral devices, expansion cards, software proliferated. "IBM compatible" became an important criterion for sales growth. International Business Machines, one of the world's largest companies, had a 62% share of the mainframe computer market in 1982. In the late 1970s the new personal computer industry was dominated by the Commodore PET, Atari 8-bit family, Apple II, Tandy Corporation's TRS-80, various CP/M machines.
With $150 million in sales by 1979 and projected annual growth of more than 40% in the early 1980s, the microcomputer market was large enough for IBM's attention. Other large technology companies such as Hewlett-Packard, Texas Instruments, Data General had entered it, some large IBM customers were buying Apples, so the company saw introducing its own personal computer as both an experiment in a new market and a defense against rivals and small. In 1980 and 1981 rumors spread of an IBM personal computer a miniaturized version of the IBM System/370, while Matsushita acknowledged that it had discussed with IBM the possibility of manufacturing a personal computer for the American company; the Japanese project, codenamed "Go", ended before the 1981 release of the American-designed IBM PC codenamed "Chess", but two simultaneous projects further confused rumors about the forthcoming product. Data General and TI's small computers were not successful, but observers expected AT&T to soon enter the computer industry, other large companies such as Exxon, Montgomery Ward and Sony were designing their own microcomputers.
Xerox produced the 820 to introduce a personal computer before IBM, becoming the second Fortune 500 company after Tandy to do so, had its Xerox PARC laboratory's sophisticated technology. Whether IBM had waited too long to enter an industry in which Tandy and others were successful was unclear. An observer stated that "IBM bringing out a personal computer would be like teaching an elephant to tap dance." Successful microcomputer company Vector Graphic's fiscal 1980 revenue was $12 million. A single IBM computer in the early 1960s cost as much as $9 million, occupied one quarter acre of air-conditioned space, had a staff of 60 people; the "Colossus of Armonk" only sold through its own sales force, had no experience with resellers or retail stores, did not introduce the first product designed to work with non-IBM equipment until 1980. Another observer claimed that IBM made decisions so that, when tested, "what they found is that it would take at least nine months to ship an empty box"; as with other large computer companies, its new products required about four to five years for development.
IBM had to learn how to develop, mass-produce, market new computers. While the company traditionally let others pioneer a new market—IBM released its first commercial computer a year after Remington Rand's UNIVAC in 1951, but within five years had 85% of the market—the personal-computer development and pricing cycles were much faster than for mainframes, with products designed in a few months and obsolete quickly. Many in the microcomputer industry resented IBM's power and wealth, disliked the perception that an industry founded by startups needed a latecomer so staid that it had a strict dress code and employee songbook; the potential importance to microcomputers of a company so prestigious, that a popular saying in American companies stated "No one got fired for buying IBM", was nonetheless clear. InfoWorld, which described itself as "The Newsweekly for Microcomputer Users", stated that "for my grandmother, for millions of people like her, IBM and computer are synonymous". Byte stated in an editorial just before the announcement of the IBM PC: Rumors abound about personal computers to come from giants such as Digital Equipment Corporation and the General Electric Company.
But there is no contest. IBM's new personal computer... is far and away the media star, not because of its features, but because it exists at all. When the number eight company in the Fortune 500 enters the field, news... The influence of a personal computer made by a company whose name has come to mean "computer" to most of the world is hard to contemplate; the editorial acknowledged that "some factions in our industry have looked upon IBM as the'enemy'", but concluded with optimism: "I want to see personal computing take a giant step." Desktop sized programmable calculators by HP had evolved into the HP 9830 BASIC language computer by 1972. In 1972–1973 a team led by Dr. Paul Friedl at the IBM Los Gatos Scientific Center developed a portable computer prototype called SCAMP (Special Computer APL Machine Po
The Sinclair ZX80 is a home computer launched on 29 January 1980 by Science of Cambridge Ltd.. It is notable for being one of the first computers available in the United Kingdom for less than a hundred pounds, it was available in kit form for £79.95, where purchasers had to assemble and solder it together, as a ready-built version at £99.95. The ZX80 was popular straight away, for some time there was a waiting list of several months for either version of the machine; the ZX80 was named after the Z80 processor with the'X' for "the mystery ingredient". Internally, the machine was designed by Jim Westwood around a Z80 central processing unit with a clock speed of 3.25 MHz, was equipped with 1 KB of static RAM and 4 KB of read-only memory. It had no sound output; the ZX80 was designed around available TTL chips. The successor ZX81 used a semi-custom chip which combined the functions of much of the earlier hardware onto a single chip reducing the chip-count from 21 to 4; however this was a cost-reduction effort.
Both computers can be made by hobbyists using commercially available discrete logic FPGAs. The ROM contained the Sinclair BASIC programming language and operating system. BASIC commands were not entered by typing them out but were instead selected somewhat to a programmable graphing calculator - each key had a few different functions selected by both context and modes as well as with the shift key; the machine was mounted in a small white plastic case, with a one-piece blue membrane keyboard on the front. There were problems with durability and overheating. Display was over an RF connection to a household television, 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, popularised by Don Lancaster in his 1978 book The TV Cheap Video Cookbook and his "TV Typewriter"; 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 when pressing a key for any input, the display would, blank 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 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. Another issue was that the main RAM was used to store the screen display, with the result that the available screen size would decrease as the size of a program increased. Video output was character-based. However, the ZX80 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 weren't an issue when the system was sold outside the UK. 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, the ZX Spectrum, which encouraged a small cottage industry of expansion devices, including memory packs and floppy drives. The original Sinclair ZX80 RAM Pack held either 1, 2 or 3 KB of static RAM and a model held 16 KB of dynamic RAM. 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 ZX81 manual. Taking off the top cover of the ZX80 and prying the old ROM from its socket and inserting the new ROM and adding the keyboard overlay, the ZX80 would now function identically to the proper ZX81 – except for SLOW mode, due to the differences in hardware between the two models; the process was reversed to return the ZX80 to its original configuration. 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.
The UK version of the machine was the standard, only changes that were necessary to sell units in other markets were made. In fact, the only real change made in most markets involved the video output frequency. 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", the character set and keyboard included the Pound symbol; the ZX
The MK14 was a computer kit sold by Science of Cambridge of the United Kingdom, first introduced in 1977 for UK£39.95. The price was low for a complete computer system at the time, Science of Cambridge sold over fifteen thousand kits. In 1977, Ian Williamson approached Clive Sinclair and Chris Curry with a computer design based around the National Semiconductor SC/MP processor. Sinclair and Curry both liked the idea and saw the potential of making a low cost microprocessor system available to the hobbyist market, it was planned to market a kit based on the Williamson design. However, after National Semiconductor had been contacted regarding a bulk purchase of the SC/MP processor Sinclair and Curry decided to use the chip manufacturer's own design; this design used all National Semiconductor chips and the company allowed the use of its design for free. To keep costs low a membrane keypad was used; the size of the initial batch was two thousand. The company sold between fifty thousand in total; the computer is based around National Semiconductor's SC/MP CPU and shipped with 256 bytes of random access memory as standard.
It used an eight or nine red light-emitting diode seven segment display, there was optional VDU supporting 32×16 text or 64×64 graphics. Input and output was reset switch. Cassette-based and PROM storage were optional extras, a sound card was not included but a design for one was provided; the on-board RAM could be increased in two ways. These memory spaces were not contiguous in the memory map, it was possible to connect off-board RAM giving a 2170 bytes total. The MK14 could address up to 64 KB of memory space by adding a few chips. Microprocessor development board MK14 manual Old-computers.com dedicated page, pictures and videos The Sinclair / Science of Cambridge MK14 Web Site, includes emulator software Making a reproduction MK14 – includes original manuals/schematics
An operating system is system software that manages computer hardware and software resources and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is executed directly by the hardware and makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers; the dominant desktop operating system is Microsoft Windows with a market share of around 82.74%. MacOS by Apple Inc. is in second place, the varieties of Linux are collectively in third place. In the mobile sector, use in 2017 is up to 70% of Google's Android and according to third quarter 2016 data, Android on smartphones is dominant with 87.5 percent and a growth rate 10.3 percent per year, followed by Apple's iOS with 12.1 percent and a per year decrease in market share of 5.2 percent, while other operating systems amount to just 0.3 percent.
Linux distributions are dominant in supercomputing sectors. Other specialized classes of operating systems, such as embedded and real-time systems, exist for many applications. A single-tasking system can only run one program at a time, while a multi-tasking operating system allows more than one program to be running in concurrency; this is achieved by time-sharing, where the available processor time is divided between multiple processes. These processes are each interrupted in time slices by a task-scheduling subsystem of the operating system. Multi-tasking may be characterized in co-operative types. In preemptive multitasking, the operating system slices the CPU time and dedicates a slot to each of the programs. Unix-like operating systems, such as Solaris and Linux—as well as non-Unix-like, such as AmigaOS—support preemptive multitasking. Cooperative multitasking is achieved by relying on each process to provide time to the other processes in a defined manner. 16-bit versions of Microsoft Windows used cooperative multi-tasking.
32-bit versions of both Windows NT and Win9x, used preemptive multi-tasking. Single-user operating systems have no facilities to distinguish users, but may allow multiple programs to run in tandem. A multi-user operating system extends the basic concept of multi-tasking with facilities that identify processes and resources, such as disk space, belonging to multiple users, the system permits multiple users to interact with the system at the same time. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources to multiple users. A distributed operating system manages a group of distinct computers and makes them appear to be a single computer; the development of networked computers that could be linked and communicate with each other gave rise to distributed computing. Distributed computations are carried out on more than one machine; when computers in a group work in cooperation, they form a distributed system.
In an OS, distributed and cloud computing context, templating refers to creating a single virtual machine image as a guest operating system saving it as a tool for multiple running virtual machines. The technique is used both in virtualization and cloud computing management, is common in large server warehouses. Embedded operating systems are designed to be used in embedded computer systems, they are designed to operate on small machines like PDAs with less autonomy. They are able to operate with a limited number of resources, they are compact and efficient by design. Windows CE and Minix 3 are some examples of embedded operating systems. A real-time operating system is an operating system that guarantees to process events or data by a specific moment in time. A real-time operating system may be single- or multi-tasking, but when multitasking, it uses specialized scheduling algorithms so that a deterministic nature of behavior is achieved. An event-driven system switches between tasks based on their priorities or external events while time-sharing operating systems switch tasks based on clock interrupts.
A library operating system is one in which the services that a typical operating system provides, such as networking, are provided in the form of libraries and composed with the application and configuration code to construct a unikernel: a specialized, single address space, machine image that can be deployed to cloud or embedded environments. Early computers were built to perform a series of single tasks, like a calculator. Basic operating system features were developed in the 1950s, such as resident monitor functions that could automatically run different programs in succession to speed up processing. Operating systems did not exist in their more complex forms until the early 1960s. Hardware features were added, that enabled use of runtime libraries and parallel processing; when personal computers became popular in the 1980s, operating systems were made for them similar in concept to those used on larger computers. In the 1940s, the earliest electronic digital systems had no operating systems.
Electronic systems of this time were programmed on rows of mechanical switches or by jumper wires on plug boards. These were special-purpose systems that, for example, generated ballistics tables for the military or controlled the pri