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The British Broadcasting Corporation Microcomputer System, or BBC Micro, is a series of
microcomputer
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 (PC ...
s and associated peripherals designed and built by
Acorn Computers
Acorn Computers Ltd. was a British computer company established in Cambridge, England, in 1978. The company produced a number of computers which were especially popular in the United Kingdom, UK, including the Acorn Electron and the Acorn Archi ...
in the 1980s for the
BBC #REDIRECT BBC #REDIRECT BBC
Here i going to introduce about the best teacher of my life b BALAJI sir. He is the precious gift that I got befor 2yrs . How has helped and thought all the concept and made my success in the 10th board exam. ...
...
Computer Literacy Project. Designed with an emphasis on education, it was notable for its ruggedness, expandability, and the quality of its
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...
. An accompanying 1982 television series, ''
The Computer Programme
''The Computer Programme'' is a TV series, produced by Paul Kriwaczek, originally broadcast by the BBC (on BBC 2) in 1982. The idea behind the series was to introduce people to computers and show them what they were capable of. The BBC wanted ...
'', featuring
Chris Serle
Christopher Richard Serle (born 13 July 1943 in Bristol, England) is a former BBC TV presenter, reporter and actor.
Biography
Serle was educated at Clifton College and Trinity College, Dublin, where he studied modern languages. He appeared as ...
learning to use the machine, was broadcast on
BBC2
BBC Two is a British free-to-air public broadcast television network owned and operated by the BBC. It covers a wide range of subject matter, with a remit "to broadcast programmes of depth and substance" in contrast to the more mainstream an ...
.
After the Literacy Project's
call for bids
An invitation to tender (ITT, otherwise known as a call for bids or a request for tenders) is a formal, structured procedure for generating competing offers from different potential suppliers or contractors looking to obtain an award of business ...
for a computer to accompany the
TV programmes and literature, Acorn won the contract with the ''Proton'', a successor of its
Atom
Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons.
Every solid, liquid, gas, and ...
computer prototyped at short notice. Renamed the BBC Micro, the system was adopted by most schools in the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...
, changing Acorn's fortunes. It was also successful as a
home computer in the UK, despite its high cost. Acorn later employed the machine to simulate and develop the
ARM architecture
ARM (stylised in lowercase as arm, formerly an acronym for Advanced RISC Machines and originally Acorn RISC Machine) is a family of reduced instruction set computer (RISC) instruction set architectures for computer processors, configured ...
.
While nine models were eventually produced with the BBC brand, the phrase "BBC Micro" is usually used colloquially to refer to the first six (Model A, B, B+64, B+128, Master 128, and Master Compact); subsequent BBC models are considered part of
Acorn's Archimedes series.
History
![BBC Micro people in 2008](https://upload.wikimedia.org/wikipedia/commons/e/e1/BBC_Micro_people_in_2008.jpg)
During the early 1980s, the BBC started what became known as the ''BBC Computer Literacy Project''. The project was initiated partly in response to an
ITV
ITV or iTV may refer to:
ITV
*Independent Television (ITV), a British television network, consisting of:
** ITV (TV network), a free-to-air national commercial television network covering the United Kingdom, the Isle of Man, and the Channel Islan ...
documentary series ''The Mighty Micro'', in which
Christopher Evans of the UK's
National Physical Laboratory predicted the coming
microcomputer revolution
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 ...
and its effect on the economy, industry, and lifestyle of the United Kingdom.
The BBC wanted to base its project on a
microcomputer
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 (PC ...
capable of performing various tasks which they could then demonstrate in the TV series ''
The Computer Programme
''The Computer Programme'' is a TV series, produced by Paul Kriwaczek, originally broadcast by the BBC (on BBC 2) in 1982. The idea behind the series was to introduce people to computers and show them what they were capable of. The BBC wanted ...
''. The list of topics included
programming,
graphics
Graphics () are visual images or designs on some surface, such as a wall, canvas, screen, paper, or stone, to inform, illustrate, or entertain. In contemporary usage, it includes a pictorial representation of data, as in design and manufacture ...
, sound and music,
teletext
A British Ceefax football index page from October 2009, showing the three-digit page numbers for a variety of football news stories
Teletext, or broadcast teletext, is a standard for displaying text and rudimentary graphics on suitably equipp ...
, controlling external hardware, and
artificial intelligence
Artificial intelligence (AI) is intelligence—perceiving, synthesizing, and inferring information—demonstrated by machines, as opposed to intelligence displayed by animals and humans. Example tasks in which this is done include speech re ...
. It developed an ambitious specification for a BBC computer, and discussed the project with several companies including
Acorn Computers
Acorn Computers Ltd. was a British computer company established in Cambridge, England, in 1978. The company produced a number of computers which were especially popular in the United Kingdom, UK, including the Acorn Electron and the Acorn Archi ...
,
Sinclair Research
Sinclair Research Ltd is a British consumer electronics company founded by Clive Sinclair in Cambridge. It was originally incorporated in 1973 as Westminster Mail Order Ltd, renamed Sinclair Instrument Ltd, then Science of Cambridge Ltd, the ...
, Newbury Laboratories,
Tangerine Computer Systems
Tangerine Computer Systems was a British microcomputer company founded in 1979 by Dr. Paul Johnson, Mark Rainer and Nigel Penton Tilbury in St. Ives, Cambridgeshire.
The very first product was the successful TAN1648 VDU kit which received muc ...
, and
Dragon Data
Dragon Data Ltd. was a Welsh producer of home computers during the early 1980s. These computers, the Dragon 32 and Dragon 64, strongly resembled the Tandy TRS-80 Color Computer ("CoCo")—both followed a standard Motorola datasheet confi ...
.
The introduction of a specific microcomputer to a more general computer literacy initiative was a topic of controversy, however, with criticism aimed at the BBC for promoting a specific commercial product and for going beyond the "traditional BBC pattern" of promoting existing information networks of training and education providers. Accusations were even levelled at the Department of Industry for making the BBC "an arm of Government industrial policy" and using the Computer Literacy Project as a way of "funding industry through the back door", obscuring public financial support on behalf of a government that was ostensibly opposed to subsidising industry.
The Acorn team had already been working on a successor to their existing ''
Atom
Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons.
Every solid, liquid, gas, and ...
'' microcomputer. Known as the ''Proton'', it included better graphics and a faster 2 MHz
MOS Technology 6502
The MOS Technology 6502 (typically pronounced "sixty-five-oh-two" or "six-five-oh-two") William Mensch and the moderator both pronounce the 6502 microprocessor as ''"sixty-five-oh-two"''. is an 8-bit microprocessor that was designed by a small t ...
central processing unit
A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, an ...
. The machine was only at the design stage at the time, and the Acorn team, including
Steve Furber
Stephen Byram Furber (born 21 March 1953) is a British computer scientist, mathematician and hardware engineer, currently the ICL Professor of Computer Engineering in the Department of Computer Science at the University of Manchester, UK. A ...
and
Sophie Wilson
Sophie Mary Wilson (born Roger Wilson; June 1957) is an English computer scientist, who helped design the BBC Micro and ARM architecture.
Wilson first designed a microcomputer during a break from studies at Selwyn College, Cambridge. She su ...
, had one week to build a working prototype from the sketched designs.
The team worked through the night to get a working Proton together to show the BBC.
Although BBC expected a computer with the
Zilog Z80
The Z80 is an 8-bit microprocessor introduced by Zilog as the startup company's first product. The Z80 was conceived by Federico Faggin in late 1974 and developed by him and his 11 employees starting in early 1975. The first working samples wer ...
CPU and
CP/M
CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system created in 1974 for Intel 8080/ 85-based microcomputers by Gary Kildall of Digital Research, Inc. Initial ...
operating system, not the Proton's 6502 CPU and proprietary operating system, the Proton was the only machine to match the BBC's specification; it also exceeded the specification in nearly every parameter.
Based on the Proton prototype the BBC signed a contract with Acorn as early as February 1981; by June the BBC Micro's specifications and pricing were decided. As a concession to the BBC's expectation of "industry standard" compatibility with CP/M, apparently under the direction of John Coll, the
Tube
Tube or tubes may refer to:
* ''Tube'' (2003 film), a 2003 Korean film
* ''The Tube'' (TV series), a music related TV series by Channel 4 in the United Kingdom
* "Tubes" (Peter Dale), performer on the Soccer AM television show
* Tube (band), a ...
interface was incorporated into the design, enabling a Z80 second processor to be added.
A new contract between Acorn and BBC Enterprises was agreed in 1984 for another four-year term, with other manufacturers having tendered for the deal. An Acorn representative admitted that the BBC Model B would not be competitive throughout the term of the renewed contract and that a successor would emerge.
The OS
ROM
Rom, or ROM may refer to:
Biomechanics and medicine
* Risk of mortality, a medical classification to estimate the likelihood of death for a patient
* Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac
* R ...
v1.0 contains the following ASCII credits string (cod
here:
(C) 1981 Acorn Computers Ltd.Thanks are due to the following contributors to the development of the BBC Computer (among others too numerous to mention):- David Allen,Bob Austin,Ram Banerjee,Paul Bond,Allen Boothroyd,Cambridge,Cleartone,John Coll,John Cox,Andy Cripps,Chris Curry,6502 designers,Jeremy Dion,Tim Dobson,Joe Dunn,Paul Farrell,Ferranti,Steve Furber,Jon Gibbons,Andrew Gordon,Lawrence Hardwick,Dylan Harris,Hermann Hauser,Hitachi,Andy Hopper,ICL,Martin Jackson,Brian Jones,Chris Jordan,David King,David Kitson,Paul Kriwaczek,Computer Laboratory,Peter Miller,Arthur Norman,Glyn Phillips,Mike Prees,John Radcliffe,Wilberforce Road,Peter Robinson,Richard Russell,Kim Spence-Jones,Graham Tebby,Jon Thackray,Chris Turner,Adrian Warner,Roger Wilson,Alan Wright.
Additionally, the last bytes of the BASIC ROM (v2 and v4) include the word "Roger", which is a reference to
Sophie Wilson
Sophie Mary Wilson (born Roger Wilson; June 1957) is an English computer scientist, who helped design the BBC Micro and ARM architecture.
Wilson first designed a microcomputer during a break from studies at Selwyn College, Cambridge. She su ...
whose name at the time was Roger Wilson.
Market impact
![Acorn BBC B microcomputer - keyboard](https://upload.wikimedia.org/wikipedia/commons/e/ee/Acorn_BBC_B_microcomputer_-_keyboard.jpg)
The machine was released as the BBC Microcomputer on 1 December 1981, although production problems pushed delivery of the majority of the initial run into 1982.
Nicknamed "the Beeb",
it was popular in the UK, especially in the educational market; about 80% of British schools had a BBC microcomputer.
''
BYTE
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...
'' called the BBC Micro Model B "a no-compromise computer that has many uses beyond self-instruction in computer technology". It called the
Tube interface "the most innovative feature" of the computer, and concluded that "although some other British microcomputers offer more features for a given price, none of them surpass the BBC ... in terms of versatility and expansion capability".
As with
Sinclair Research
Sinclair Research Ltd is a British consumer electronics company founded by Clive Sinclair in Cambridge. It was originally incorporated in 1973 as Westminster Mail Order Ltd, renamed Sinclair Instrument Ltd, then Science of Cambridge Ltd, the ...
's
ZX Spectrum
The ZX Spectrum () is an 8-bit computing, 8-bit home computer that was developed by Sinclair Research. It was released in the United Kingdom on 23 April 1982, and became Britain's best-selling microcomputer.
Referred to during development as t ...
and
Commodore International
Commodore International (other names include Commodore International Limited) was an American home computer and electronics manufacturer founded by Jack Tramiel. Commodore International (CI), along with its subsidiary Commodore Business Mach ...
's
Commodore 64
The Commodore 64, also known as the C64, is an 8-bit home computer introduced in January 1982 by Commodore International (first shown at the Consumer Electronics Show, January 7–10, 1982, in Las Vegas). It has been listed in the Guinness ...
, both released the following year, in 1982, demand greatly exceeded supply. For some months, there were long delays before customers received the machines they had ordered.
The involvement of the BBC in microcomputing also initiated tentative plans by the independent television companies of the
ITV network
ITV is a British free-to-air public broadcast television network. It was launched in 1955 as Independent Television to provide competition to BBC Television (established in 1936). ITV is the oldest commercial network in the UK. Since the passin ...
to introduce their own initiative and rival computing system, with a CP/M-based system proposed by Transam Computers under consideration for such an initiative by the Independent Television Companies Association at a late 1983 meeting. The proposed machine would have been priced at £399, matching that of the BBC Model B, and was reported as offering 64 KB of RAM, a disc interface, and serial and parallel interfaces, itself being a "low-cost development" of an existing machine, the Transam Tuscan, which included dual floppy drives and cost £1,700.
This proposal was voted down by the ITV companies citing a possible contravention of the companies' obligations under broadcasting regulations prohibiting sponsorship, along with concerns about a conflict of interest with advertisers of computer products.
Despite denials of involvement with ITV from Prism Microproducts, the company had already been pursuing a joint venture with Transam on a product rumoured to be under consideration by the broadcasting group.
This product, a business system subsequently known as the Wren,
had reportedly been positioned as such an "ITV Micro" towards the end of 1983, also to be offered in a home variant with
ORACLE
An oracle is a person or agency considered to provide wise and insightful counsel or prophetic predictions, most notably including precognition of the future, inspired by deities. As such, it is a form of divination.
Description
The word '' ...
teletext reception capabilities. However, not all ITV franchise holders were equally enthusiastic about scheduling programmes related to microcomputing or about pursuing a computer retailing strategy.
Efforts were made to market the machine in the United States and West Germany.
By October 1983, the US operation reported that American schools had placed orders with it totalling .
In one deployment in Lowell, Massachusetts valued at $177,000, 138 BBC Micros were installed in eight of the 27 schools in the city, with the computer's networking capabilities, educational credentials, and the availability of software with "high education quality" accompanied by "useful lesson plans and workbooks" all given as reasons for selecting Acorn's machine in preference to the competition from IBM, Apple and Commodore.
Another deployment in Phoenix, Arizona valued at $174,697 saw 175 BBC Micros installed, with the local Acorn dealer predicting sales worth in the following two years, split between 85 to 90 percent in education and the remainder in small business. In early 1984, Acorn claimed a US network of more than 1,000 dealers.
In October 1984, while preparing a major expansion of its US dealer network, Acorn claimed sales of 85 per cent of the computers in British schools, and delivery of 40,000 machines per month.
That December, Acorn stated its intention to become the market leader in US educational computing.
''
The New York Times
''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid ...
'' considered the inclusion of
local area networking
A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. By contrast, a wide area network (WAN) not only covers a larger ...
to be of prime importance to teachers.
The operation resulted in advertisements by at least one dealer in ''Interface Age'' magazine, but ultimately the attempt failed.
The success of the machine in the UK was due largely to its acceptance as an "educational" computer – UK schools used BBC Micros to teach
computer literacy
Computer literacy is defined as the knowledge and ability to use computers and related technology efficiently, with skill levels ranging from elementary use to computer programming and advanced problem solving. Computer literacy can also refer ...
, information technology skills.
Acorn became more known for its computer than for its other products.
Some Commonwealth countries, including
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
, started their own computer literacy programmes around 1984.
Intending to avoid "re-inventing the wheel", such efforts adopted the BBC Micro in order to take immediate advantage of the extensive range of software already developed under the United Kingdom's own literacy initiative, proposing that software tailored for local requirements would ultimately also be developed.
A clone of the BBC Micro was produced by Semiconductor Complex Limited and named the SCL Unicorn. Another Indian computer manufacturer, Hope Computers Pvt Ltd, made a BBC Micro clone called the Dolphin. Unlike the original BBC Micro, the Dolphin featured blue function keys.
Production agreements were made with both SCL in India and distributor Harry Mazal in Mexico for the assembly of BBC Micro units from kits of parts, leading to full-scale manufacturing, with SCL also planning to fabricate the 6502 CPU under licence from Rockwell.
According to reporting from early 1985, "several thousand Beebs a month" were being produced in India. Meanwhile, the eventual production arrangement in Mexico involved local manufacturer Datum, aiming to assemble 2000 units per month by May 1985, with the initial assembly intended to lead to the manufacture of all aspects of the machines apart from Acorn's proprietary ULA components. Such machines were intended for the Mexican and South American markets, potentially also appealing to those south-western states of the US having large Spanish-speaking populations.
Ultimately, upon Acorn's withdrawal from the US in 1986, Datum would continue manufacturing at a level of 7000 to 8000 Spanish-language machines per year for the North and South American markets.
The initial strategy for the BBC's computer literacy endeavour involved the marketing of the "Acorn Proton-based BBC microcomputer for less than £200".
The Model A and the Model B were initially priced at £235 and £335 respectively, but increased almost immediately to £299 and £399 due to higher costs.
The price of nearly £400 was roughly £1200
(€1393)
in 2011 prices (or around £ today). Acorn anticipated the total sales to be around 12,000 units, but eventually more than 1.5 million BBC Micros were sold.
The cost of the BBC Models was high compared to competitors such as the ZX Spectrum and the Commodore 64, and from 1983 on Acorn attempted to counter this by producing a simplified but largely compatible version intended for home use, complementing the use of the BBC Micro in schools: the 32K
Acorn Electron
The Acorn Electron (nicknamed the Elk inside Acorn and beyond) was a lower-cost alternative to the BBC Micro educational/ home computer, also developed by Acorn Computers Ltd, to provide many of the features of that more expensive machine at a ...
.
Description
Hardware features: Models A and B
![BBC Micro rear](https://upload.wikimedia.org/wikipedia/commons/2/29/BBC_Micro_rear.jpeg)
A key feature of the BBC Micro's design is the high-performance
RAM
Ram, ram, or RAM may refer to:
Animals
* A male sheep
* Ram cichlid, a freshwater tropical fish
People
* Ram (given name)
* Ram (surname)
* Ram (director) (Ramsubramaniam), an Indian Tamil film director
* RAM (musician) (born 1974), Dutch
* ...
it is equipped with. A common design note in
6502 computers of the era was to run the RAM at twice the clock rate as the CPU. This allows a separate
video display controller
A video display controller or VDC (also called a display engine or display interface) is an integrated circuit which is the main component in a video-signal generator, a device responsible for the production of a TV video signal in a computing ...
to access memory while the CPU is busy processing the data just read. In this way, the CPU and graphics driver can share access to RAM through careful timing. This technique is used, for example, on the
Apple
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple fruit tree, trees are agriculture, cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, wh ...
and the early
Commodore
Commodore may refer to:
Ranks
* Commodore (rank), a naval rank
** Commodore (Royal Navy), in the United Kingdom
** Commodore (United States)
** Commodore (Canada)
** Commodore (Finland)
** Commodore (Germany) or ''Kommodore''
* Air commodore, a ...
models.
The BBC machine, however, was designed to run at the faster CPU speed, 2
MHz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...
, double that of these earlier machines. In this case,
bus contention
Bus contention is an undesirable state in computer design where more than one device on a bus attempts to place values on it at the same time.
Bus contention is the kind of telecommunication contention that occurs when all communicating devi ...
is normally an issue, as there is not enough time for the CPU to access the memory during the period when the video hardware is idle. Some machines of the era accept the inherent performance hit, as is the case for the
Amstrad CPC
The Amstrad CPC (short for ''Colour Personal Computer'') is a series of 8-bit home computers produced by Amstrad between 1984 and 1990. It was designed to compete in the mid-1980s home computer market dominated by the Commodore 64 and the Sin ...
,
Atari 8-bit family
The Atari 8-bit family is a series of 8-bit home computers introduced by Atari, Inc. in 1979 as the Atari 400 and Atari 800. The series was successively upgraded to Atari 1200XL , Atari 600XL, Atari 800XL, Atari 65XE, Atari 130XE, Atari 800XE, ...
, and to a lesser extent the
ZX Spectrum
The ZX Spectrum () is an 8-bit computing, 8-bit home computer that was developed by Sinclair Research. It was released in the United Kingdom on 23 April 1982, and became Britain's best-selling microcomputer.
Referred to during development as t ...
. Others, like the
MSX systems, use entirely separate pools of memory for the CPU and video, slowing access between the two.
Furber believed that the Acorn design should have a
flat memory model
Flat memory model or linear memory model refers to a memory addressing paradigm in which "memory appears to the program as a single contiguous address space." The CPU can directly (and linearly) address all of the available memory locations witho ...
and allow the CPU and video system to access the bus without interfering with each other. To do so, the RAM has to allow four million access cycles per second.
Hitachi
() is a Japanese multinational corporation, multinational Conglomerate (company), conglomerate corporation headquartered in Chiyoda, Tokyo, Japan. It is the parent company of the Hitachi Group (''Hitachi Gurūpu'') and had formed part of the Ni ...
was the only company considering a
DRAM
Dynamic random-access memory (dynamic RAM or DRAM) is a type of random-access semiconductor memory that stores each bit of data in a memory cell, usually consisting of a tiny capacitor and a transistor, both typically based on metal-oxid ...
that runs at that speed, the HM4816. To equip the prototype machine, the only four 4816s in the country were hand-carried by the Hitachi representative to Acorn.
The National Semiconductor 81LS95
multiplexer
In electronics, a multiplexer (or mux; spelled sometimes as multiplexor), also known as a data selector, is a device that selects between several analog or digital input signals and forwards the selected input to a single output line. The sel ...
is needed for the high memory speed. Furber recalled that competitors came to Acorn offering to replace the component with their own, but "none of them worked. And we never knew why. Which of course means we didn't know why the National Semiconductor one ''did'' work correctly. And a million and a half BBC Micros later it was still working and I still didn't know why". Another mystery was the 6502's
data bus
In computer architecture, a bus (shortened form of the Latin '' omnibus'', and historically also called data highway or databus) is a communication system that transfers data between components inside a computer, or between computers. This ex ...
. The prototype BBC Micro exceeded the CPU's specifications, causing it to fail. The designers found that putting a finger on a certain place on the motherboard caused the prototype to work. Acorn put a
resistor
A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active el ...
pack across the data bus, which Furber described as the engineer's finger' and again, we have no idea why it's necessary, and a million and a half machines later it's still working, so nobody asked any questions".
The Model A shipped with 16
KB of user RAM, while the Model B had 32 KB. Extra ROMs can be fitted (four on the PCB or sixteen with expansion hardware) and accessed vi
paged memory
The machines includes three video ports, one with an
RF modulator
An RF modulator (or radio frequency modulator) is an electronic device whose input is a baseband signal which is used to modulate a radio frequency source.
RF modulators are used to convert signals from devices such as media players, VCRs and ...
sending out a signal in the
UHF
Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter (on ...
band, another sending
composite video
Composite video is an analog video signal format that carries standard-definition video (typically at 525 lines or 625 lines) as a single channel. Video information is encoded on one channel, unlike the higher-quality S-Video (two channels) a ...
suitable for connection to
computer monitor
A computer monitor is an output device that displays information in pictorial or textual form. A discrete monitor comprises a visual display, support electronics, power supply, housing, electrical connectors, and external user controls.
The di ...
s, and a separate
RGB video
The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three addit ...
port. The separate RGB video out socket was an engineering requirement from the BBC to allow the machine to directly output a broadcast quality signal for use within television programming; it is used on episodes of ''
The Computer Programme
''The Computer Programme'' is a TV series, produced by Paul Kriwaczek, originally broadcast by the BBC (on BBC 2) in 1982. The idea behind the series was to introduce people to computers and show them what they were capable of. The BBC wanted ...
'' and ''
Making the Most of the Micro''.
The computer includes several
input/output
In computing, input/output (I/O, or informally io or IO) is the communication between an information processing system, such as a computer, and the outside world, possibly a human or another information processing system. Inputs are the signals ...
interfaces:
serial and
parallel
Parallel is a geometric term of location which may refer to:
Computing
* Parallel algorithm
* Parallel computing
* Parallel metaheuristic
* Parallel (software), a UNIX utility for running programs in parallel
* Parallel Sysplex, a cluster of IBM ...
printer ports, an 8-bit general purpose digital I/O port, a port offering four
analogue inputs, a light pen input, and an expansion connector (the "1 MHz bus") that enables other hardware to be connected. An
Econet
Econet was Acorn Computers's low-cost local area network system, intended for use by schools and small businesses. It was widely used in those areas, and was supported by a large number of different computer and server systems produced both by ...
network interface and a disk drive interface were available as options. All motherboards have space for the electronic components, but Econet is rarely installed.
Additionally, an Acorn proprietary interface named the "
Tube
Tube or tubes may refer to:
* ''Tube'' (2003 film), a 2003 Korean film
* ''The Tube'' (TV series), a music related TV series by Channel 4 in the United Kingdom
* "Tubes" (Peter Dale), performer on the Soccer AM television show
* Tube (band), a ...
" allows a second processor to be added. Three models of second processor were offered by Acorn, based on the
6502
The MOS Technology 6502 (typically pronounced "sixty-five-oh-two" or "six-five-oh-two") William Mensch and the moderator both pronounce the 6502 microprocessor as ''"sixty-five-oh-two"''. is an 8-bit microprocessor that was designed by a small te ...
,
Z80
The Z80 is an 8-bit microprocessor introduced by Zilog as the startup company's first product. The Z80 was conceived by Federico Faggin in late 1974 and developed by him and his 11 employees starting in early 1975. The first working samples were ...
and
32016 CPUs. The Tube is used for third-party add-ons, including a Z80 board and
hard disk drive
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnet ...
from Torch that allows the BBC machine to run CP/M programs.
Separate pages, each with a codename, are used to control the access to the I/O:
The Tube interface allowed Acorn to use BBC Micros with
ARM
In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between the ...
CPUs as software development machines when creating the
Acorn Archimedes
Acorn Archimedes is a family of personal computers designed by Acorn Computers of Cambridge, Cambridge, England. The systems are based on Acorn's own ARM architecture processors and the proprietary operating systems Arthur and RISC OS. The fi ...
. This resulted in the ARM development kit for the BBC Micro in 1986, priced at around £4000. From 2006, a kit with an
ARM7TDMI
ARM7 is a group of 32-bit RISC ARM processor cores licensed by ARM Holdings for microcontroller use. The ARM7 core family consists of ARM700, ARM710, ARM7DI, ARM710a, ARM720T, ARM740T, ARM710T, ARM7TDMI, ARM7TDMI-S, ARM7EJ-S. The ARM7TDMI an ...
CPU running at 64 MHz, with as much as 64 MB of RAM, was released for the BBC Micro and Master, using the Tube interface to upgrade the 8-bit micros into 32-bit RISC machines. Among the software that operated on the Tube are an enhanced version of the ''
Elite
In political and sociological theory, the elite (french: élite, from la, eligere, to select or to sort out) are a small group of powerful people who hold a disproportionate amount of wealth, privilege, political power, or skill in a group. D ...
'' video game and a
computer-aided design
Computer-aided design (CAD) is the use of computers (or ) to aid in the creation, modification, analysis, or optimization of a design. This software is used to increase the productivity of the designer, improve the quality of design, improve c ...
system that requires a second 6502 CPU and a 3-dimensional joystick named a "Bitsti
The Model A and the Model B are built on the same
printed circuit board
A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in Electrical engineering, electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a L ...
(PCB), and a Model A can be upgraded to a Model B. Users wishing to operate Model B software need to add the extra RAM and the user/printer
MOS Technology 6522
The 6522 Versatile Interface Adapter (VIA) is an integrated circuit that was designed and manufactured by MOS Technology as an I/O port controller for the MOS Technology 6502, 6502 family of microprocessors. It provides two bidirectional 8-bit p ...
VIA (which many games use for timers) and snip a link, a task that can be achieved without soldering. To do a full upgrade with all the external ports requires soldering the connectors to the motherboard. The original machines shipped with "OS 0.1", with later updates advertised in magazines, supplied as a clip-in integrated circuit, with the last official version being "OS 1.2". Variations in the Acorn OS exist as a result of home-made projects and modified machines can still be bought on internet auction sites such as
eBay
eBay Inc. ( ) is an American multinational e-commerce company based in San Jose, California, that facilitates consumer-to-consumer and business-to-consumer sales through its website. eBay was founded by Pierre Omidyar in 1995 and became a ...
as of 2011.
The BBC Model A was phased out of production with the introduction of the
Acorn Electron
The Acorn Electron (nicknamed the Elk inside Acorn and beyond) was a lower-cost alternative to the BBC Micro educational/ home computer, also developed by Acorn Computers Ltd, to provide many of the features of that more expensive machine at a ...
, with chairman Chris Curry stating at the time that Acorn "would no longer promote it" (the Model A).
Early BBC Micros use
linear power supplies at the insistence of the BBC which, as a broadcaster, was cautious about
electromagnetic interference
Electromagnetic interference (EMI), also called radio-frequency interference (RFI) when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electros ...
. The supplies were unreliable, and after a few months the BBC allowed
switched mode units.
An apparent oversight in the manufacturing process resulted in many Model Bs producing a constant buzzing noise from the built-in speaker. This fault can be rectified partly by soldering a resistor across two pads.
There are five developments of the main BBC Micro circuit board that addressed various issues through the models production, from 'Issue 1' through to 'Issue 7' with variants 5 and 6 not being released. The 1985 'BBC Microcomputer Service Manual' from Acorn documents the details of the technical changes.
Per
Watford Electronics comments in their '32K Ram Board Manual':
Export models
Two export models were developed: one for the US,
[
] with Econet and speech hardware as standard; the other for
West Germany
West Germany is the colloquial term used to indicate the Federal Republic of Germany (FRG; german: Bundesrepublik Deutschland , BRD) between its formation on 23 May 1949 and the German reunification through the accession of East Germany on 3 O ...
.
The computer was unsuitable for the Australian market because, Furber said, the design failed above .
Export models are fitted with
radio frequency shielding as required by the respective countries. From June 1983 the name was always spelled out completely – "British Broadcasting Corporation Microcomputer System" – to avoid confusion with
Brown, Boveri & Cie
Brown, Boveri & Cie. (Brown, Boveri & Company; BBC) was a Swiss group of electrical engineering companies.
It was founded in Zürich, in 1891 by Charles Eugene Lancelot Brown and Walter Boveri who worked at the Maschinenfabrik Oerlikon. In 1 ...
in international markets,
after warnings from the Swiss multinational not to market the computer with the BBC label in West Germany, thus forcing Acorn to relabel "hundreds of machines" to comply with these demands.
US models include the BASIC III ROM chip, modified to accept the American spelling of
COLOR
, but the height of the graphics display was reduced to 200
scan line
A scan line (also scanline) is one line, or row, in a raster scanning pattern, such as a line of video on a cathode ray tube (CRT) display of a television set or computer monitor.
On CRT screens the horizontal scan lines are visually discernible ...
s to suit
NTSC
The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...
TVs,
[
] severely affecting applications written for British computers. After the failed US marketing campaign the unwanted machines were
remanufactured for the British market and sold, resulting in a third 'UK export' variant.
Side product
In October 1984, the
Acorn Business Computer (ABC)/Acorn Cambridge Workstation range of machines was announced, based primarily on BBC hardware.
Hardware features: successor models
B+64 and B+128
In mid-1985, Acorn introduced the Model B+ which increased the total RAM to 64 KB. This had a modest market impact and received a rather unsympathetic reception, with one reviewer's assessment being that the machine was "18 months too late" and that it "must be seen as a stop gap",
and others criticising the elevated price of £500 (compared to the £400 of the original Model B) in the face of significantly cheaper competition providing as much or even twice as much memory.
The extra RAM in the Model B+ is assigned as two blocks, a block of 20 KB dedicated solely for screen display (so-called
shadow RAM
Random-access memory (RAM; ) is a form of computer memory that can be read and changed in any order, typically used to store working data and machine code. A random-access memory device allows data items to be read or written in almost the s ...
) and a block of 12 KB of special
sideways RAM. The B+128, introduced towards the end of 1985,
comes with an additional 64 KB (4 × 16 KB sideways RAM banks) to give a total RAM of 128 KB.
The B+ is incapable of operating some original BBC B programs and games, such as the very popular
''Castle Quest''. A particular problem is the replacement of the
Intel 8271 floppy-disk controller
A floppy-disk controller (FDC) has evolved from a discrete set of components on one or more circuit boards to a special-purpose integrated circuit (IC or "chip") or a component thereof. An FDC directs and controls reading from and writing to ...
with the
Western Digital 1770: not only was the new controller mapped to different addresses,
it is fundamentally incompatible and the 8271 emulators that existed were necessarily imperfect for all but basic operation.
Software that use
copy protection
Copy protection, also known as content protection, copy prevention and copy restriction, describes measures to enforce copyright by preventing the reproduction of software, films, music, and other media.
Copy protection is most commonly found on ...
techniques involving direct access to the controller do not operate on the new system.
Acorn attempted to alleviate this, starting with version 2.20 of the 1770 DFS, via an 8271-backward- compatible ++ option.
There is also a long-running problem late in the B/B+'s commercial life infamous amongst B+ owners, when Superior Software released ''
Repton Infinity,'' which did not run on the B+. A series of unsuccessful replacements were issued before one compatible with both was finally released.
BBC Master
During 1986, Acorn followed up with the
BBC Master
The BBC Master is a home computer released by Acorn Computers in early 1986. It was designed and built for the BBC, British Broadcasting Corporation (BBC) and was the successor to the BBC Micro, BBC Micro Model B. The Master 128 remained in produ ...
, which offers memory sizes from 128 KB and many other refinements which improves on the 1981 original. It has essentially the same 6502-based BBC architecture, with many of the upgrades that the original design intentionally makes possible (extra ROM software, extra paged RAM, second processors) now included on the circuit board as internal plug-in modules.
Software
The BBC Micro platform amassed a large software base of both games and educational programs for its two main uses as a home and educational computer. Notable examples of each include the original release of ''
Elite
In political and sociological theory, the elite (french: élite, from la, eligere, to select or to sort out) are a small group of powerful people who hold a disproportionate amount of wealth, privilege, political power, or skill in a group. D ...
'' and ''
Granny's Garden''.
Programming language
A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language.
The description of a programming ...
s and some applications were supplied on ROM chips to be installed on the motherboard. These load instantly and leave the RAM free for programs or documents.
Although appropriate content was little-supported by television broadcasters,
telesoftware
The term telesoftware was coined by W.J.G. Overington who invented the concept in 1974; it literally means “software at a distance” and it often refers to the transmission of programs for a microprocessor or home computer via broadcast telete ...
could be downloaded via the optional
Teletext Adapter and the third-party teletext adaptors that emerged.
The built-in operating system,
Acorn MOS
The Machine Operating System (MOS) or OS is a discontinued computer operating system (OS) used in Acorn Computers' BBC computer range. It included support for four-channel sound, graphics, file system abstraction, and digital and analogue inp ...
, provides an extensive
API
An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software Interface (computing), interface, offering a service to other pieces of software. A document or standa ...
to interface with all standard peripherals, ROM-based software, and the screen. Features specific to some versions of BASIC, like
vector graphics
Vector graphics is a form of computer graphics in which visual images are created directly from geometric shapes defined on a Cartesian plane, such as points, lines, curves and polygons. The associated mechanisms may include vector display a ...
,
keyboard macros, cursor-based editing, sound queues, and
envelopes
An envelope is a common packaging item, usually made of thin, flat material. It is designed to contain a flat object, such as a letter or card.
Traditional envelopes are made from sheets of paper cut to one of three shapes: a rhombus, a shor ...
, are in the MOS ROM and made available to any application. BBC BASIC itself, being in a separate ROM, can be replaced with another language.
BASIC, other languages, and utility ROM chips reside in any of four 16 KB ''paged ROM'' sockets, with OS support for sixteen sockets via expansion hardware. The five (total) sockets are located partially obscured under the keyboard, with the leftmost socket hard-wired for the OS. The intended purpose for the perforated panel on the left of the keyboard was for a Serial ROM or Speech ROM. The paged ROM system is essentially modular. A language-independent system of ''star commands'', prefixed with an asterisk, provides the ability to select a language (for example
*BASIC
,
*PASCAL
), a filing system (
*TAPE
,
*DISC
), change settings (
*FX
,
*OPT
), or carry out ROM-supplied tasks (
*COPY
,
*BACKUP
) from the command line. The MOS recognises certain built-in commands, and polls the paged ROMs in descending order for service otherwise; if none of them claims the command then the OS returns a
Bad command
error. Suitable ROM (or EPROM) images could be written and provide functions without requiring RAM for the code itself.
Not all ROMs offer star commands (ROMs containing data files, for instance), but any ROM can "
hook
A hook is a tool consisting of a length of material, typically metal, that contains a portion that is curved or indented, such that it can be used to grab onto, connect, or otherwise attach itself onto another object. In a number of uses, one e ...
" into vectors to enhance the system's functionality. Often the ROM is a
device driver
In computing, a device driver is a computer program that operates or controls a particular type of device that is attached to a computer or automaton. A driver provides a software interface to hardware devices, enabling operating systems and ot ...
for
mass storage
In computing, mass storage refers to the storage of large amounts of data in a persisting and machine-readable fashion. In general, the term is used as large in relation to contemporaneous hard disk drives, but it has been used large in relati ...
combined with a filing system, starting with Acorn's 1982
Disc Filing System
The Disc Filing System (DFS) is a computer file system developed by Acorn Computers, initially as an add-on to the Eurocard-based Acorn System 2.
In 1981, the Education Departments of Western Australia and South Australia announced joint tende ...
whose API became the ''de facto'' standard for floppy-disc access. The Acorn Graphics Extension ROM (GXR) expands the VDU routines to draw geometric shapes, flood fills, and sprites. During 1985
Micro Power
Micro Power was a British company established in the early 1980s by former accountant Bob Simpson. The company was best known as a video game publisher, originally under the name Program Power. It also sold many types of computer hardware and so ...
designed and marketed a Basic Extension ROM, introducing statements such as
WHILE
,
ENDWHILE
,
CASE
,
WHEN
,
OTHERWISE
, and
ENDCASE
, as well as direct mode commands including
VERIFY
.
Acorn strongly discouraged programmers from directly accessing the system variables and hardware, favouring official
system call
In computing, a system call (commonly abbreviated to syscall) is the programmatic way in which a computer program requests a service from the operating system on which it is executed. This may include hardware-related services (for example, acc ...
s.
This was ostensibly to make sure programs keep working when migrated to coprocessors that utilise the Tube interface, but it also makes BBC Micro software more portable across the Acorn range. Whereas untrappable
PEEKs and POKEs are used by other computers to reach the system elements, programs in either machine code or BBC BASIC instead pass parameters to an operating system routine. In this way the 6502 can translate the request for the local machine or send it across the Tube interface, as direct access is impossible from the coprocessor. Published programs largely conform to the API except for games, which routinely engage with the hardware for greater speed, and require a particular Acorn model.
Many schools and universities employed the machines in
Econet
Econet was Acorn Computers's low-cost local area network system, intended for use by schools and small businesses. It was widely used in those areas, and was supported by a large number of different computer and server systems produced both by ...
networks, and so networked multiplayer games were possible. Few became popular, due to the limited number of machines aggregated in one place. A relatively late but well documented example can be found in a dissertation based on a ringed
RS-423
RS-423, also known as TIA/EIA-423, is a technical standard originated by the Electronic Industries Alliance that specifies electrical characteristics of a digital signaling circuit. Although it was originally intended as a successor to RS-232C of ...
interconnect.
BBC BASIC built-in programming language
![Hard reset BBC Micro 32K Acorn DFS](https://upload.wikimedia.org/wikipedia/commons/0/0e/Hard_reset_BBC_Micro_32K_Acorn_DFS.gif)
The built-in ROM-resident ''BBC BASIC'' programming language
interpreter realised the system's educational emphasis and was key to its success; it is the most comprehensive BASIC compared to other contemporary implementations, and runs very efficiently. Advanced programs can be written without resorting to
non-structured programming
Non-structured programming is the historically earliest programming paradigm capable of creating Turing-complete algorithms. It is often contrasted with the structured programming paradigm, in particular with the use of unstructured control flow us ...
or machine code. Should one want or need to do some assembly programming, BBC BASIC has a built-in assembler that allows a mixture of BASIC and assembler for whatever processor BASIC was operating on.
When the BBC Micro was released, many competing home computers used
Microsoft BASIC
Microsoft BASIC is the foundation software product of the Microsoft company and evolved into a line of BASIC interpreters and compiler(s) adapted for many different microcomputers. It first appeared in 1975 as Altair BASIC, which was the first ve ...
, or variants typically designed to resemble it. Compared to Microsoft BASIC, BBC BASIC features IF...THEN...ELSE, REPEAT...UNTIL, and named procedures and functions, but retains
GOTO
GoTo (goto, GOTO, GO TO or other case combinations, depending on the programming language) is a statement found in many computer programming languages. It performs a one-way transfer of control to another line of code; in contrast a function ca ...
and
GOSUB
BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages designed for ease of use. The original version was created by John G. Kemeny and Thomas E. Kurtz at Dartmouth College ...
for compatibility. It also supports high-resolution graphics, four-channel sound, pointer-based memory access (borrowed from
BCPL
BCPL ("Basic Combined Programming Language") is a procedural, imperative, and structured programming language. Originally intended for writing compilers for other languages, BCPL is no longer in common use. However, its influence is still ...
), and rudimentary macro assembly. Long variable names are accepted and distinguished completely, not just by the first two characters.
Other languages
Acorn had made a point of not just supporting BBC Basic but also supporting a number of contemporary languages, some of which were supplied as ROM chips to fit the spare sideways ROM sockets on the motherboard. Other languages were supplied on tape or disk.
Programming languages from
Acornsoft
Acornsoft was the software arm of Acorn Computers, and a major publisher of software for the BBC Micro and Acorn Electron. As well as games, it also produced a large number of educational titles, extra computer languages and business and util ...
included the following:
* ISO
Pascal
Pascal, Pascal's or PASCAL may refer to:
People and fictional characters
* Pascal (given name), including a list of people with the name
* Pascal (surname), including a list of people and fictional characters with the name
** Blaise Pascal, Fren ...
(2× 16 KB ROM + floppy disk)
* S-Pascal (disk or tape)
*
BCPL
BCPL ("Basic Combined Programming Language") is a procedural, imperative, and structured programming language. Originally intended for writing compilers for other languages, BCPL is no longer in common use. However, its influence is still ...
(ROM plus further optional disk based modules)
*
Forth
Forth or FORTH may refer to:
Arts and entertainment
* ''forth'' magazine, an Internet magazine
* ''Forth'' (album), by The Verve, 2008
* ''Forth'', a 2011 album by Proto-Kaw
* Radio Forth, a group of independent local radio stations in Scotla ...
(16 KB ROM)
*
LISP
A lisp is a speech impairment in which a person misarticulates sibilants (, , , , , , , ). These misarticulations often result in unclear speech.
Types
* A frontal lisp occurs when the tongue is placed anterior to the target. Interdental lisping ...
(disk, tape or ROM)
*
Logo
A logo (abbreviation of logotype; ) is a graphic mark, emblem, or symbol used to aid and promote public identification and recognition. It may be of an abstract or figurative design or include the text of the name it represents as in a wordma ...
(2× 16 KB ROM)
* Turtle Graphics (disk or tape)
* Micro-
PROLOG
Prolog is a logic programming language associated with artificial intelligence and computational linguistics.
Prolog has its roots in first-order logic, a formal logic, and unlike many other programming languages, Prolog is intended primarily ...
(16 KB ROM)
* COMAL (16 KB ROM)
* C (disk)
Many of these languages were also provided under the
Panos environment for the
32016 Second Processor. As the
Z80 Second Processor provided a CP/M environment, languages available for CP/M were supportable via this route. For example,
Turbo Pascal
Turbo Pascal is a software development system that includes a compiler and an integrated development environment (IDE) for the Pascal (programming language), Pascal programming language running on CP/M, CP/M-86, and DOS. It was originally develo ...
was regarded in one instance as "by far the best version of Pascal" for a BBC Micro with Z80 second processor.
DOS-based language implementations such as
Turbo C
Turbo C is a discontinued integrated development environment (IDE) and compiler for the C programming language from Borland. First introduced in 1987, it was noted for its integrated development environment, small size, fast compile speed, compr ...
and Turbo Pascal could also be run by computers expanded with the Master 512 board,
this being fitted to BBC Micro machines using a Universal Second Processor unit.
Torch Computers
Torch Computers Ltd was a computer hardware company with origins in a 1982 joint venture between Acorn Computers and Climar Group that led to the development of the Communicator or C-series computer, a system based on the BBC Micro with a Z80 se ...
' Z80 expansions supported the
UCSD p-System
UCSD Pascal is a Pascal programming language system that runs on the UCSD p-System, a portable, highly machine-independent operating system. UCSD Pascal was first released in 1977. It was developed at the University of California, San Diego (UCS ...
, and the Torch Unicorn expansion provided a Unix environment that featured a C compiler and other utilities, with Pascal and Fortran 77 implementations also advertised.
Acornsoft C did not run on the original BBC Micro models, requiring the extra resources provided by the B+ and Master series machines. Beebug C did, however, run on the standard Model B and later machines. Both of these implementations provided compilers producing interpreted "p-code" as opposed to machine code, similar to Acornsoft's ISO Pascal and BCPL compilers. A
Small-C
Small-C is both a subset of the C programming language, suitable for resource-limited microcomputers and embedded systems, and an implementation of that subset. Originally valuable as an early compiler for microcomputer systems available during t ...
implementation was also made available by Mijas.
For a BBC Micro without a second processor, Acornsoft's ISO Pascal primarily saw competition from Oxford Pascal. A Forth-based Pascal implementation from HCCS known as Pascal T was regarded as being "intended primarily for learning Pascal, rather than using it seriously",
putting it in the same category as Acornsoft's S-Pascal, described as "a simple subset of Pascal for teaching the language and structured programming".
Peripherals
In line with its ethos of expandability Acorn produced its own range of peripherals for the BBC Micro, including:
* Joysticks
* Tape recorder
* Floppy drive interface upgrade
* Floppy drives (single and double)
* Econet networking upgrade
*
Econet Bridge
* Winchester disk system
*
6502 Second Processor
*
Z80 Second processor (with CP/M and business software suite)
*
32016 Second processor
*
ARM Evaluation System
*
Teletext adapter
*
Prestel adapter
* Speech synthesiser
* Music 500 synthesiser
* BBC
Turtle (robot)
Turtles are a class of educational robots designed originally in the late 1940s (largely under the auspices of researcher William Grey Walter) and used in computer science and mechanical engineering training. These devices are traditionally built l ...
* BBC Buggy
*
IEEE 488 Interface
Various products from other manufacturers competed directly with Acorn's expansions. For example, companies such as
Torch Computers
Torch Computers Ltd was a computer hardware company with origins in a 1982 joint venture between Acorn Computers and Climar Group that led to the development of the Communicator or C-series computer, a system based on the BBC Micro with a Z80 se ...
and Cambridge Microprocessor Systems offered second processor solutions for the BBC Micro.
A large number of third-party suppliers also produced an abundance of add-on hardware, some of the most common being:
* RGB monitors
* Printers, plotters
* Modems
Successor machines
Acorn produced their own
32-bit
In computer architecture, 32-bit computing refers to computer systems with a processor, memory, and other major system components that operate on data in 32-bit units. Compared to smaller bit widths, 32-bit computers can perform large calculation ...
Reduced Instruction Set Computing
In computer engineering, a reduced instruction set computer (RISC) is a computer designed to simplify the individual instructions given to the computer to accomplish tasks. Compared to the instructions given to a complex instruction set comput ...
(RISC)
CPU during 1985, the ARM1. Furber composed a reference model of the processor on the BBC Micro with 808 lines of BASIC, and Arm Ltd. retains copies of the code for intellectual property purposes.
[ The Acorn World exhibition was held in Huddersfield.] The first prototype ARM platforms, the ARM Evaluation System and the A500 workstation, functioned as second processors attached to the BBC Micro's Tube interface. Acorn staff developed the A500's operating system ''in situ'' through the Tube until, one by one, the on-board I/O ports were enabled and the A500 ran as a stand-alone computer.
With an upgraded processor this was eventually released during 1987 as four models in the ''Archimedes'' series, the lower-specified two models (512 KB and 1 MB) continuing the BBC Microcomputer brand with the distinctive red function keys. Although the Archimedes ultimately was not a major success, the ARM family of processors has become the dominant processor architecture in mobile embedded consumer devices, particularly mobile telephones.
Acorn's last BBC-related model, the BBC A3000, was released in 1989. It was essentially a 1 MB Archimedes back in a single case
form factor.
Retro computing scene
![Hermann Hauser playing Blurp 2012](https://upload.wikimedia.org/wikipedia/commons/8/8d/Hermann_Hauser_playing_Blurp_2012.jpg)
Furber said in 2015 that he was amazed that the BBC Micro "established this reputation for being reliable, because lots of it was finger-in-the-air engineering". As of 2018, thanks to its ready expandability and I/O functions, there are still numbers of BBC Micros in use, and a
retrocomputing
Retrocomputing is the use of older computer hardware and software in modern times. Retrocomputing is usually classed as a hobby and recreation rather than a practical application of technology; enthusiasts often collect rare and valuable hardw ...
community of dedicated users finding new tasks for the old hardware. They still survive in a few interactive displays in museums across the United Kingdom, and the
Jodrell Bank
Jodrell Bank Observatory () in Cheshire, England, hosts a number of radio telescopes as part of the Jodrell Bank Centre for Astrophysics at the University of Manchester. The observatory was established in 1945 by Bernard Lovell, a radio astron ...
observatory was reported using a BBC Micro to steer its 42 ft radio telescope in 2004.
Furber said that although "the
ngineeringmargins on the Beeb were very, very small", when he asked BBC owners at a retrocomputing meeting what components had failed after 30 years, they said "you have to replace the
capacitor
A capacitor is a device that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. It is a passive electronic component with two terminals.
The effect of ...
s in the power supply but everything else still works". The Archimedes came with 65Arthur, an
emulator
In computing, an emulator is Computer hardware, hardware or software that enables one computer system (called the ''host'') to behave like another computer system (called the ''guest''). An emulator typically enables the host system to run so ...
which ''
BYTE
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...
'' stated "lets many programs for the BBC Micro run";
other emulators exist for many operating systems.
![BBC Micro creators with micro in 2012](https://upload.wikimedia.org/wikipedia/commons/e/e0/BBC_Micro_creators_with_micro_in_2012.jpg)
In March 2008, the creators of the BBC Micro met at the
Science Museum
A science museum is a museum devoted primarily to science. Older science museums tended to concentrate on static displays of objects related to natural history, paleontology, geology, industry and industrial machinery, etc. Modern trends in mu ...
in London. There was to be an exhibition about the computer and its legacy during 2009.
The UK
National Museum of Computing
The National Museum of Computing is a museum in the United Kingdom dedicated to collecting and restoring historic computer systems. The museum is based in rented premises at Bletchley Park in Milton Keynes, Buckinghamshire and opened in 200 ...
at
Bletchley Park
Bletchley Park is an English country house and estate in Bletchley, Milton Keynes ( Buckinghamshire) that became the principal centre of Allied code-breaking during the Second World War. The mansion was constructed during the years following ...
uses BBC Micros as part of a scheme to educate school children about computer programming.
In March 2012, the BBC and Acorn teams responsible for the BBC Micro and Computer Literacy Project met for a 30th anniversary party, entitled "Beeb@30". This was held at
Arm
In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between the ...
's offices in Cambridge and was co-hosted by the
Centre for Computing History
The Centre for Computing History is a museum in Cambridge, England, established to create a permanent public exhibition telling the story of the Information Age.
Overview
The museum acts as a repository for vintage computers and related artefac ...
.
Continued development and support
Long after the "venerable old Beeb"
was superseded, additional hardware and software has been developed. Such developments have included Sprow's 1999
zip compression
Compression may refer to:
Physical science
*Compression (physics), size reduction due to forces
*Compression member, a structural element such as a column
*Compressibility, susceptibility to compression
* Gas compression
*Compression ratio, of a ...
utility and a
ROM
Rom, or ROM may refer to:
Biomechanics and medicine
* Risk of mortality, a medical classification to estimate the likelihood of death for a patient
* Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac
* R ...
Y2K bugfix
The year 2000 problem, also known as the Y2K problem, Y2K scare, millennium bug, Y2K bug, Y2K glitch, Y2K error, or simply Y2K refers to potential computer errors related to the formatting and storage of calendar data for dates in and after ...
for the
BBC Master
The BBC Master is a home computer released by Acorn Computers in early 1986. It was designed and built for the BBC, British Broadcasting Corporation (BBC) and was the successor to the BBC Micro, BBC Micro Model B. The Master 128 remained in produ ...
.
There are also a number of websites still supporting both hardware and software development for the BBC Micros and Acorn in general.
Specifications (Model A to Model B+128)
Display modes
Like the
IBM PC
The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 12, 1981, it was created by a team ...
with the contemporary
Color Graphics Adapter
The Color Graphics Adapter (CGA), originally also called the ''Color/Graphics Adapter'' or ''IBM Color/Graphics Monitor Adapter'', introduced in 1981, was IBM's first color graphics card for the IBM PC and established a de facto computer display ...
, the video output of the BBC Micro could be switched by software between a number of
display mode
Computer display standards are a combination of Display aspect ratio, aspect ratio, display size, display resolution, color depth, and refresh rate. They are associated with specific expansion cards, Audio and video interfaces and connectors#Vide ...
s. These varied between 20 and 40-column text suitable for a domestic TV and 80-column text best viewed with a high-quality RGB-connected monitor; the latter mode was often too blurred to view when using a domestic TV via the UHF output. The variety of modes offered applications a flexible compromise between colour depth, resolution and memory economy. In the first models, the OS and applications were left with the RAM left over from the display mode.
Mode 7 was a
Teletext
A British Ceefax football index page from October 2009, showing the three-digit page numbers for a variety of football news stories
Teletext, or broadcast teletext, is a standard for displaying text and rudimentary graphics on suitably equipp ...
mode, extremely economical on memory and an original requirement due to the BBC's own use of broadcast teletext (Ceefax). It also made the computer useful as a
Prestel
Prestel (abbrev. from press telephone), the brand name for the UK Post Office Telecommunications's Viewdata technology, was an interactive videotex system developed during the late 1970s and commercially launched in 1979. It achieved a maximu ...
terminal. The teletext characters were generated using an
SAA5050
The Mullard SAA5050 was a character generator chip for implementing the Teletext character set. The SAA5050 was used in teletext-equipped television sets, viewdata terminals, and microcomputers, most notably on computers like the Philips P2000 ( ...
chip, for use with monitors and TV sets without a Teletext receiver. Mode 7 used only 1 KB for video RAM by storing each character as its ASCII code, rather than its bitmap image as was needed for the other modes.
Modes 0 to 6 could display colours from a logical palette of sixteen: the eight basic colours at the vertices of the RGB color model, RGB colour cube and eight flashing colours made by alternating the basic colour with its inverse. The palette could be freely reprogrammed without touching display memory. Modes 3 and 6 were special text-only modes that used less RAM by reducing the number of text rows and inserting blank scan lines below each row. Mode 6 was the smallest, allocating 8 KB as video memory. Modes 0 to 6 could show diacritics and other user defined characters. All modes except mode 7 supported bitmapped graphics, but graphics commands such as DRAW and PLOT had no effect in the text-only modes.
The BBC B+ and the later Master provided 'shadow modes', where the 1–20 KB frame buffer was stored in an alternative RAM bank, freeing the main memory for user programs. This feature was requested by setting bit 7 of the mode variable, i.e. by requesting modes 128–135.
Optional extras
A speech synthesis upgrade based on the Texas Instruments TMS5220 featured sampled words spoken by BBC newscaster Kenneth Kendall.
This speech system was standard on the US model where it had an American vocabulary. The Computer Concepts Speech ROM also made use of the TMS5220 speech processor but not the speech ROMs, instead driving the speech processor directly.
The speech upgrade sold poorly and was largely superseded by Superior Software's software-based synthesiser using the standard sound hardware.
The speech upgrade also added two empty sockets next to the keyboard, intended for 16 KB serial ROM cartridges containing either extra speech phoneme data beyond that held in the speech paged ROM or general software accessed through the ROM Filing System. The original plan was that some games would be released on cartridges, but due to the limited sales of the speech upgrade combined with economic and other viability concerns,
little or no software was ever produced for these sockets. The cut-out space next to the keyboard (nicknamed the "ashtray") was more commonly used to install other upgrades, such as a ZIF socket for conventional paged ROMs.
Use in the entertainment industry
The BBC Domesday Project, a pioneering multimedia experiment, was based on a modified version of the BBC Micro's successor, the
BBC Master
The BBC Master is a home computer released by Acorn Computers in early 1986. It was designed and built for the BBC, British Broadcasting Corporation (BBC) and was the successor to the BBC Micro, BBC Micro Model B. The Master 128 remained in produ ...
.
Musician Vince Clarke of the British synth pop bands Depeche Mode, Yazoo (band), Yazoo, and Erasure used a BBC Micro (and later a
BBC Master
The BBC Master is a home computer released by Acorn Computers in early 1986. It was designed and built for the BBC, British Broadcasting Corporation (BBC) and was the successor to the BBC Micro, BBC Micro Model B. The Master 128 remained in produ ...
) with the UMI music sequencer to compose many hits.
In music videos from the 1980s featuring Vince Clarke, a BBC Micro is often present or provides text and graphics such as a clip for Erasure's "Oh L'Amour". The musical group Queen (band), Queen used the UMI Music Sequencer on their record ''A Kind of Magic''. The UMI is also mentioned in the CD booklet. Other bands who have used the BBC Micro for making music are A-ha and the reggae band Steel Pulse. Paul Ridout is credited as "UMI programmer" on The Cars, Cars' bassist/vocalist Benjamin Orr's 1986 solo album, The Lace (Benjamin Orr album), The Lace. Other UMI users included Blancmange (band), Blancmange, Alan Parsons and Robert John "Mutt" Lange, Mutt Lange. Black Uhuru used the Envelope Generator from SYSTEM software (Sheffield) running on a BBC Micro, to create some of the electro-dub sounds on Try It (Anthem (Black Uhuru album), Anthem album 1983).
The BBC Micro was used extensively to provide graphics and sound effects for many early 1980s BBC TV shows. These included, notably, series 3 and 4 of ''The Adventure Game''; the children's quiz game "First Class" (where the onscreen scoreboard was provided by a BBC Micro nicknamed "Eugene"); and numerous 1980s episodes of ''Doctor Who'' including "Castrovalva (Doctor Who), Castrovalva", "The Five Doctors", and "The Twin Dilemma".
Legacy
In 2013, NESTA released
report into the legacy of The BBC Micro looking at the history and impact of the machine and The BBC Computer Literacy project. In June 2018, the BBC released its archives of the ''Computer Literacy Project''.
The BBC Micro had a lasting technological impact on the education market by introducing an informal educational standard around the hardware and software technologies employed by the range, particularly the use of BBC BASIC, and by establishing a considerable investment by schools in software for the machine. Consequently, manufacturers of rival systems such as IBM PC compatibles (and almost-compatibles such as the RM Nimbus), the Apple Macintosh, and the Commodore Amiga, as well as Acorn as the manufacturer of the BBC Micro's successor, the Archimedes, were compelled to provide a degree of compatibility with the large number of machines already deployed in schools.
See also
*
Acorn Electron
The Acorn Electron (nicknamed the Elk inside Acorn and beyond) was a lower-cost alternative to the BBC Micro educational/ home computer, also developed by Acorn Computers Ltd, to provide many of the features of that more expensive machine at a ...
*
Acorn Archimedes
Acorn Archimedes is a family of personal computers designed by Acorn Computers of Cambridge, Cambridge, England. The systems are based on Acorn's own ARM architecture processors and the proprietary operating systems Arthur and RISC OS. The fi ...
* BBC Computer Literacy Project 2012
*
BBC Master
The BBC Master is a home computer released by Acorn Computers in early 1986. It was designed and built for the BBC, British Broadcasting Corporation (BBC) and was the successor to the BBC Micro, BBC Micro Model B. The Master 128 remained in produ ...
* Raspberry Pi
* RiscPC
* Micro Bit – modern successor to the project
* TV
** ''Micro Men'' – BBC documentary drama
** ''Micro Live'' – BBC television programme
** ''
Making the Most of the Micro'' – BBC television programme
* Magazines
** BEEBUG – user group magazine
** (BBC) Acorn User
** The Micro User (also known as ''Acorn Computing'')
* NDR computer
* WDR computer
References
External links
*
BeebWiki– BBC Micro Wiki
* [https://web.archive.org/web/20190322233256/http://www.computinghistory.org.uk/det/182/Acorn-BBC-Micro-Model-B/ The Acorn BBC Micro @ The Centre for Computing History]
BBC Micro connected to the Internet converting RSS headline feeds from the BBC News site into audio
Video of a BBC computer show from 1985
{{DEFAULTSORT:Bbc Micro
Products introduced in 1981
Acorn Computers
Computers designed in the United Kingdom
6502-based home computers
Home computers
BBC computer literacy projects, Micro
Home video game consoles