SCELBI was an early model of microcomputer based on the Intel 8008 processor. The company SCELBI (derived from SCientific-ELectronics-BIology) Computer Consulting in 1973, [1] by Nat Wadsworth. The SCELBI 8H was marketed in 1974 and was delivered either as an assembled unit or as a kit, with five basic circuit boards and provision for memory expansion to 16 KB (16,384 bytes). The company offered input/output devices including a keyboard, teleprinter interface, alphanumeric oscilloscope interface, and a cassette tape interface for data storage. The basic system only used a front panel with 11 switches and LEDs for input and output.
The company also offered a version of the BASIC programming language called SCELBAL. Optional modules for strings and transcendental functions allowed the system to operate in small memory configurations. SCELBAL was sold in book format, allowing it to be used on any similar 8008 or 8080 based platform.
The initial model 8H was discontinued at the end of 1974 and an improved model 8B was introduced. Fewer than 150 board sets and assembled systems were ever sold. [2] Later in 1975, the availability of systems based on the more flexible 8080 processor reduced demand for the slower 8008-based product. The company discovered that the demand for books on microcomputers was very high and published several books; the publishing business was sold in 1982.
The Intel 8080 ("eighty-eighty") is the second 8-bit microprocessor designed and manufactured by Intel. It first appeared in April 1974 and is an extended and enhanced variant of the earlier 8008 design, although without binary compatibility. The initial specified clock rate or frequency limit was 2 MHz, with common instructions using 4, 5, 7, 10, or 11 clock cycles. As a result, the processor is able to execute several hundred thousand instructions per second. Two faster variants, the 8080A-1 and 8080A-2, became available later with clock frequency limits of 3.125 MHz and 2.63 MHz respectively. The 8080 needs two support chips to function in most applications: the i8224 clock generator/driver and the i8228 bus controller. The 8080 is implemented in N-type metal–oxide–semiconductor logic (NMOS) using non-saturated enhancement mode transistors as loads thus demanding a +12 V and a −5 V voltage in addition to the main transistor–transistor logic (TTL) compatible +5 V.
The 6800 is an 8-bit microprocessor designed and first manufactured by Motorola in 1974. The MC6800 microprocessor was part of the M6800 Microcomputer System that also included serial and parallel interface ICs, RAM, ROM and other support chips. A significant design feature was that the M6800 family of ICs required only a single five-volt power supply at a time when most other microprocessors required three voltages. The M6800 Microcomputer System was announced in March 1974 and was in full production by the end of that year.
The Zilog Z80 is an 8-bit microprocessor designed by Zilog that played an important role in the evolution of early computing. Software-compatible with the Intel 8080, it offered a compelling alternative due to its better integration and increased performance. The Z80 boasted fourteen registers compared to the 8080's seven, along with additional instructions for bit manipulation, making it a more powerful chip.
A microcomputer is a small, relatively inexpensive computer having a central processing unit (CPU) made out of a microprocessor. The computer also includes memory and input/output (I/O) circuitry together mounted on a printed circuit board (PCB). Microcomputers became popular in the 1970s and 1980s with the advent of increasingly powerful microprocessors. The predecessors to these computers, mainframes and minicomputers, were comparatively much larger and more expensive. Many microcomputers are also personal computers. An early use of the term "personal computer" in 1962 predates microprocessor-based designs. (See "Personal Computer: Computers at Companies" reference below). A "microcomputer" used as an embedded control system may have no human-readable input and output devices. "Personal computer" may be used generically or may denote an IBM PC compatible machine.
The Intel 8008 is an early 8-bit microprocessor capable of addressing 16 KB of memory, introduced in April 1972. The 8008 architecture was designed by Computer Terminal Corporation (CTC) and was implemented and manufactured by Intel. While the 8008 was originally designed for use in CTC's Datapoint 2200 programmable terminal, an agreement between CTC and Intel permitted Intel to market the chip to other customers after Seiko expressed an interest in using it for a calculator.
Tiny BASIC is a family of dialects of the BASIC programming language that can fit into 4 or fewer KBs of memory. Tiny BASIC was designed by Dennis Allison and the People's Computer Company (PCC) in response to the open letter published by Bill Gates complaining about users pirating Altair BASIC, which sold for $150. Tiny BASIC was intended to be a completely free version of BASIC that would run on the same early microcomputers.
The Altair 8800 is a microcomputer designed in 1974 by MITS and based on the Intel 8080 CPU. Interest grew quickly after it was featured on the cover of the January 1975 issue of Popular Electronics and was sold by mail order through advertisements there, in Radio-Electronics, and in other hobbyist magazines. According to Harry Garland, the Altair 8800 was the product that catalyzed the microcomputer revolution of the 1970s. It was the first commercially successful personal computer. The computer bus designed for the Altair was to become a de facto standard in the form of the S-100 bus, and the first programming language for the machine was Microsoft's founding product, Altair BASIC.
The IMSAI 8080 is an early microcomputer released in late 1975, based on the Intel 8080 and S-100 bus. It is a clone of its main competitor, the earlier MITS Altair 8800. The IMSAI is largely regarded as the first "clone" microcomputer. The IMSAI machine runs a highly modified version of the CP/M operating system called IMDOS. It was developed, manufactured and sold by IMS Associates, Inc.. In total, between 17,000 and 20,000 units were produced from 1975 to 1978.
Processor Technology Corporation was a personal computer company founded in April 1975, by Gary Ingram and Bob Marsh in Berkeley, California. Their first product was a 4K byte RAM board that was compatible with the MITS Altair 8800 computer but more reliable than the MITS board. This was followed by a series of memory and I/O boards including a video display module.
A source-to-source translator, source-to-source compiler, transcompiler, or transpiler is a type of translator that takes the source code of a program written in a programming language as its input and produces an equivalent source code in the same or a different programming language. A source-to-source translator converts between programming languages that operate at approximately the same level of abstraction, while a traditional compiler translates from a higher level programming language to a lower level programming language. For example, a source-to-source translator may perform a translation of a program from Python to JavaScript, while a traditional compiler translates from a language like C to assembly or Java to bytecode. An automatic parallelizing compiler will frequently take in a high level language program as an input and then transform the code and annotate it with parallel code annotations or language constructs.
Micral is a series of microcomputers produced by the French company Réalisation d'Études Électroniques, beginning with the Micral N in early 1973. The Micral N was one of the first commercially available microprocessor-based computer.
The DAI personal computer is an early home computer from the Belgian company Data Applications International. The DAI came to market in 1980. It provided many pioneering features such as high resolution color graphics, a maths co-processor, and a pre-compiling BASIC interpreter. However, it never became a commercial success.
The Sol-20 was the first fully assembled microcomputer with a built-in keyboard and television output, what would later be known as a home computer. The design was the integration of an Intel 8080-based motherboard, a VDM-1 graphics card, the 3P+S I/O card to drive a keyboard, and circuitry to connect to a cassette deck for program storage. Additional expansion was available via five S-100 bus slots inside the machine. It also included swappable ROMs that the manufacturer called 'personality modules', containing a rudimentary operating system.
The history of the personal computer as a mass-market consumer electronic device began with the microcomputer revolution of the 1970s. A personal computer is one intended for interactive individual use, as opposed to a mainframe computer where the end user's requests are filtered through operating staff, or a time-sharing system in which one large processor is shared by many individuals. After the development of the microprocessor, individual personal computers were low enough in cost that they eventually became affordable consumer goods. Early personal computers – generally called microcomputers – were sold often in electronic kit form and in limited numbers, and were of interest mostly to hobbyists and technicians.
Heathkit's H8 is an Intel 8080A-based microcomputer sold in kit form starting in 1977. The H8 is similar to the S-100 bus computers of the era, and like those machines is often used with the CP/M operating system on floppy disk.
Each time Intel launched a new microprocessor, they simultaneously provided a system development kit (SDK) allowing engineers, university students, and others to familiarise themselves with the new processor's concepts and features. The SDK single-board computers allowed the user to enter object code from a keyboard or upload it through a communication port, and then test run the code. The SDK boards provided a system monitor ROM to operate the keyboard and other interfaces. Kits varied in their specific features but generally offered optional memory and interface configurations, a serial terminal link, audio cassette storage, and EPROM program memory. Intel's Intellec development system could download code to the SDK boards.
A single-board microcontroller is a microcontroller built onto a single printed circuit board. This board provides all of the circuitry necessary for a useful control task: a microprocessor, I/O circuits, a clock generator, RAM, stored program memory and any necessary support ICs. The intention is that the board is immediately useful to an application developer, without requiring them to spend time and effort to develop controller hardware.
SCELBAL, short for SCientific ELementary BAsic Language, is a version of the BASIC programming language released in 1976 for the SCELBI and other early Intel 8008 and 8080-based microcomputers like the Mark-8. Later add-ons to the language included an extended math package and string handling. The original version required 8 kB of RAM, while the additions demanded at least 12 kB.
A BASIC interpreter is an interpreter that enables users to enter and run programs in the BASIC language and was, for the first part of the microcomputer era, the default application that computers would launch. Users were expected to use the BASIC interpreter to type in programs or to load programs from storage.
Martin Research Ltd., later Qwint Systems, Inc., was an American computer company founded by Donald Paul Martin in Northbrook, Illinois, United States. The company released their Mike family of modular kit microcomputers starting in 1975. These computers, spanning several models based on the Intel 8008, 8080, and Zilog Z80 microprocessors, proved very popular among hobbyists who wanted an inexpensive trainer computer.