Acorn ads

This page contains the HTML'ifyed text of Acorn's original advertising hand-outs. The text has been kindly contributed by Dave Jeffrey, and is probably copyright Acorn.

Note that some of these ads are also available as full color scans.

  • AMP 01: The BBC Micro Computer System
  • AMP 03: The BBC Microcomputer Disc Storage System
  • AMP 04: The BBC Microcomputer Teletext System
  • AMP 05: The British Broadcasting Corporation Microcomputer 6502 Second Processor
  • AMP 06: The British Broadcasting Corporation Microcomputer Z80 Second Processor
  • AMP 08: The Speech Synthesis and Cartridge ROM System for the BBC Microcomputer
  • AMP 13: The Acorn IEEE 488 Interface
  • AMP 14: The Acorn Bitstik
  • You might also be interested in this "Acorn Business Computer" ad, scanned by Mark Ferns. This computer series was announced and ready for launching when Olivetti took over Acorn and subsequently canned the whole line of products.

    AMP 01
    The BBC Micro Computer System


    The unit uses a 2MHz 6502


    Model A: 16K of Random Access Memory (RAM)
    Model B: 32K of Random Access Memory (RAM)

    A 16K Read Only Memory (ROM) integrated circuit contains an extensive and powerful Machine Operating System designed to interface easily to high level languages.

    A further 16K Language ROM contains an extremely powerful and fast BASIC interpreter. The interpreter includes a 6502 assembler which enables BASIC statements to be freely mixed with 6502 assembly language.

    Up to four 16K language ROMs may be plugged into the machine at any time. This four ROMs are 'paged' and may include Pascal, word processing, computer aided design software, disc and Econet® routines or Telextext filing system.


    73 key full travel QWERTY keyboard with 10 user definable function keys. The keyboard has two key rollover and auto repeat.


    The standard television output is 625 line 50Hz, interlaced, fully encoded PAL, modulated on UHF channel 36. Other standards are available.

    The full-colour Teletext display of 40 characters by 25 lines has full character rounding with double height, flashing, coloured background and text - all to the Teletext standard.

    The non Teletext display modes provide user definable characters in addition to the standard upper and lower case alpha-numeric font. In these modes, graphics may be freely mixed with text. Text characters can be positioned not only on, for example, a 40×32 grid, but at any intermediate position.

    Separate or overlapping text and graphic windows can be easily user-defined over any area of the display. Each of these windows may be filled separately and text may be scrolled up or down within the text window.

    The following display modes can be used
    Model B 0 640×256 2 colour graphics and 80×32 text  (20K)
    only    1 320×256 4 colour graphics and 40×32 text  (20K)
            2 160×256 16 colour graphics and 20×32 text (20K)
            3 80×25 2 colour text
    Models  4 320×256 2 colour graphics and 40×32 text  (10K)
    A and B 5 160×256 4 colour graphics and 20×32 text  (10K)
            6 40×25 2 colour text                       (8K)
            7 40×25 Teletext display                    (1K)
    The installed RAM is divided between the high resolution graphics display, the user's program and Machine Operating System variables. The Machine Operating System requires about 3½K of RAM in the Model A. If higher resolutions are required with large programs then the second processor option may be fitted.

    All graphics access is 'transparent' resulting in a fast snow-free display.

    Extensive support is provided in the Machine Operating System for the graphics facilities, and this is fully reflected in the BASIC interpreter. These facilities include the ability to draw lines raphily and to fill large areas of colour. In addition, very rapid changes of colour can be effected.

    A BNC connector supplies a composite video output to drive a black and white monitor.

    External storage

    A standard audio cassette recorder can be used to record computer programs at 300 or 1200 baud using the CUTS standard tones. The cassette recorder is under full automatic motor control and is connected to the computer via a seven pin DIN connector.

    Tone generation

    The internal loudspeaker is driven from a 3-voice music synthesis circuit with full ADSR envelope control, and there is also a noise channel.

    Interfaces(Model B only)

    Serial interfave to RS423 standard. This standard has been designed to be inter-operable with RS232C equipment but offers a considerably enhances specification - for example in maximum length of cable and maximum data transfer rates. Baud rates and software selectable between 75 baud and 19,200 baud. The interface provides not only two way data transfer, but also two way hand-shaking using RTS and CTS lines. Connection to the machine is made via a 5 way 'diamond' DIN connector and various interconnecting plugs are available for the various standard 25 way D type circuits.

    An 8 bit 'Centronics type' parallel printer port is provided with 'strobe' and 'acknowledge' lines.

    An RGB video output is provided to drive a high quality colour monitor.

    An 8 bit input/output port is also provided.

    Four 12 bit analogue input channels are provided. Each channel has an input voltage range of 0-1.8V and the interval converter provides a number in the range 0 to 4095×16. The conversion time for each channel is 10 milliseconds and when the conversion is complete, the processor is interrupted and the value stored in a memory location for later access. These analogue inputs can be used not only in laboratory control situations, but also for inputs for games - paddles or joysticks.

    A 1MHz buffered extension bus is provided for connection to Prestel, Telextext or various other expansion units.


    Both Model A** and Model B may have the expansion options fitted internally at purchase, or by dealers at a later date.
  • Floppy disc interface
  • Econet® network interface (separate leaflet available)
  • Voice synthesis circuits and cartrige ROM pack interface
  • oVarious alternative high-level languages in ROM
  • External options which plug directly into the machine inclue:
  • Paddles
  • Cassette recorders
  • Black and white and colour monitors and televisions
  • 5¼ inch single-sided disc drives (100K)
  • 5¼ inch dual double-sided double track density disc drives (800K)
  • 80 column dot-matrix printers
  • Daisy wheel printers
  • Teletext and Prestel acquisition units
    Both of these enable Telesoftware to be downloaded into the BBC Computer as well as providing access to the normal Teletext/Prestel services. Pages may be 'grabbed' and stored for later use.
  • 6502 second processor with 64K of RAM
  • Z80 second processor with 64K of RAM, a CP/M* 2.2 operating system plus software
  • 1EEE 488 interface
  • 1MHz bus for connection of extra facilities
  • Software

    Considerable attention has been paid to the overall design of the system and application software. A modular approach has been adopted specifically to ease the interfacing of various high-level languages (such as BASIC and Pascal) to the operating system.

    Machine Operating System(MOS)

    A 16K ROM is used for the MOS. This software controls all input-output devices using a well defined interface. The MOS supports the following interrupts:
  • Event timer (used as elapsed time clock)
  • 4 channel analogue to digital converter
  • Vertical sync
  • Keyboard and keyboard buffer
  • Music tone generation and buffer
  • Serial interface, input and output, and buffers
  • Parallel input/output
  • and 'hooks' are provided to support other devices such as:
  • Tube
  • Teletext filing system
  • Prestel filing system
  • Econet® filing system
  • Disc filing system
  • Many of the operating system calls are vectored to enable the user to change them if required at a future date.


    The BASIC interpreter is an extremely fast implementation, very close to the Microsoft standard but with numerous powerful extensions:
  • Long variable names
  • Integer, floating point and string variables
  • Multi-dimension integer, floating point and string arrays
  • Extensive support for string handling
  • IF...THEN...ELSE
  • Multi-line integer, floating point and string functions
  • Local variables
  • Full recursion on all functions and procedures
  • Effective error trapping and handling
  • Cassette loading and saving of programs and data
  • Full support for the extensive colour graphics facilities
  • Easy control of the built-in music generation circuits
  • Built-in 6502 mnemonic assembler enabling BASIC and assembler to be mixed, or pure assembly language programs to be produced.
  • Econet®

    The Econet® communications network enables a number of computers to share expensive resources such as a printer and a disc 'file server.' The system is primarily intended for schools and colleges but also lends itself to many office and business applications.
  • Up to 254 stations may share the network facilities
  • Connection between stations is by cheap 4 wire 'telephone' cable
  • The network may be up to 400 metres from end to end
  • Very low interface cost on each computer
  • More than one printer of file server may be on the net
  • Any station can 'view' any other similar station's screen
  • Messages may be passed between any machines
  • Stations may be plugged or unplugged at any time
  • Because of the low costs involved, it is possible to dedicate one computer as a file server and one as a printer server. However, once pupils have loded files from the file server, there is no reason why the file server computer should not be used as a normal disc computer until it is again required to act as a file server. The same flexibility applies to the printer server.


    Technical support and service can be obtained from a number of sources:
    Pre-sales advice (please send a large SAE) from
    BBC Microcomputer System
    PO Box 7 
    London W3 6XJ 
    After sales service and advice by a national dealer network (see list) and Retail Control Systems Limited, Gresham House, Twickenham Road, Feltham, Middlesex TW13 6HA

    Both Model A and Model B Computers are despatched with a mains lead and a lead to enable the computer to be connected to a domestic television set. In addition, a substantial User Guide, a cassette containing about fifteen demonstration programs and a leaflet describing these programs is included with the machine.

    This description and specification is subject to change without notice.

    *CP/M is a registered trademark of Digital Research
    **Only some expansion options are available for Model A

    AMP 01 Information Sheet G3, May 1983. The BBC Microcomputer is designed, produced and distributed in the UK by Acorn Computers Limited.

    AMP 03
    The BBC Microcomputer Disc Storage System

    Data and program storage on a cassette recorder, even under computer control as with the BBC Computer, soon becomes tiresomely laborious and the next stage is to add a disc storage facility to your system. The BBC disc system comprises two elements:

    1 The disc interface and Disc Filing System (DFS)

    This consists of various compnents including a disc controller LSI chip (8271) and a fixed memory device containing the firmware runs the filing system. These compnents should be fitted by a dealer with appropriate test equipment if not fitted at time of purchase. The DFS is very fast and uses disc space efficiently allowing access to any part of the disc within a fraction of a second and loading the program typically 60 times faster than 1200 baud tape. The DFS contains many sophisticated commands including ACCESS, BACKUP, COMPACT, COPY, DELETE, DESTROY, DIR, INFO, LIB, RENAME and TITLE.

    2 The disc drive

    This is contained in a matching case and is powered from the BBC computer. The drive is of the Shugart standard inteface and is available in two variations:
  • a Single drive providing 100Kbytes of store.
  • b Twin double sided double track density drives providing 800Kbytes of store.
  • The disc drive is provided with the BBC Microcomputer Disc Filing System manual and a floppy disc containing formatting and utilities routines.

    The DFS manual is not supplied with the disc interface components as when used with other makes of disc drive correct operation cannot be guaranteed.

    For further details ask your nearest dealer or write to
    PO Box 7, London W3 6XJ.

    AMP 04
    The BBC Microcomputer Teletext System

    The BBC Microcomputer Teletext System can accept and store teletext information transmitted by both BBC and ITV, providing access to teletext and telesoftware services broadcast on UHF channels E21 to E69.

    The Teletext system is designed to match the BBC Microcomputer in style and colour, and is supplied with cables to connect it to the computer and to the mains electricity supply, and a teletext filing system Read Only Memory (ROM) installed inside the computer. The adaptor simply connects to the television aerial, enabling the monitor to receive and decode teletext data.

    Teletext Reception

    In 'terminal mode' the system receives and decodes display pages from both CEEFAX (BBC) and ORACLE (ITV). A four channel UHF tuner demodulates incoming signals and feeds a composite video signal to a video processor. Teletext data, which is transmitted between the picture lines on a television, is stored in the system's internal 1K Random Access Memory for transmission to the BBC Microcomputer. From there it can be transferred onto tape or disc. All data processing is controlled by a ROM fitted inside the BBC Microcomputer.


    In 'telesoft mode' the system can load, run and execute programs transmitted on CEEFAX and ORACLE. Incoming signals are captured and processed as in the terminal mode, which means that programs can be run as they arrive. The BBC Microcomputer will respond to commands sent by teletext. Programs which can be sent this way are many and varied and include educational packages.

    The Teletext System can only be fitted to a Model B BBC Microcomputer, though the Model A can be upgraded. It comes complete with a User Manual.

    The microcomputer must be fitted with a Series 1.0 Machine Operating System.

    For futher details ask your nearest dealer or write to
    PO Box 7, London W3 6XJ.

    * A high-quality television signal is required to receive teletext information. Please contact your dealer for advice.

    AMP 05
    The British Broadcasting Corporation Microcomputer 6502 Second Processor

    The 6502 Second Processor has been designed for the serious computer user who wants to get even more from his British Broadcasting Corporation Microcomputer.

    Increased performance

    With the 6502 Second Processor you will be able to write bigger, more elaborate programs than you could before. Together, the 6502 Second Processor and BBC* Microcomputer make up a system which offers computing power comparable to that provided by machines costing twice as much.

    As well as writing your own programs, you will have access to a range of exciting new programs as soon as they become available. These will make full use of the additional computing power provided by the 6502 Second Processor. One of these programs drives the Bitstik computer aided drawing system, which allows the user to create shapes on the screen and produce outstanding graphics, architects' drawings, etc.

    The BBC Microcomputer was designed with a second processor in mind and incorporates Acorn's unique Tube interface. This provides a high speed data channel for the addition of a second processor. So connecting the 6502 Second Processor is simplicity itself.

    The 6502 Second Processor is presented in a matching cream coloured case and has been styled to blend with, and sit alongside, your BBC Microcomputer.

    Increased memory

    The 6502 second processor has 64K of memory. The main processor's 32K of RAM is used for screen memory, filing system work spaces, etc. This leaves the Second Processor memory free for your applications programs.

    Assembly language programs up to 60Kbytes (code and data) can be written for the Second Processor, with all the features of the BBC operating system still available across the Tube interface. When writing in BASIC, 16K of memory is needed for the interpreter. Using the special Hi-BASIC supplied with the 6502 Second Processor, 44K is available for BASIC programs. (Non 'Hi' versions of BASIC, LISP, FORTH, VIEW, etc will provide 30K of user RAM, plus a separate 14K of memory which can be used for assembly language routines or BASIC variable storage.)

    In addition, with the 6502 Second Processor connected, the full character set is completely redefinable without using any program memory.

    Increased speed

    The 6502 second processor works at a clock rate of 3MHz. This means that, depending on what you are asking your computer to do, it is likely to do it up to 50% faster than before.

    Easy to use

    Although the 6502 Second Processor is designed for the serious user, it is very easy to use. Each purchaser will receive a user guide and two additional ROMs. One of these ROMs will update your disc filing system or Econet® filing system (if fitted). The other will provide you with Hi-BASIC. It contains the same language as the BASIC ROM you already have in your micro, but allows you to make full use of the additional memory provided by the 6502 Second Processor. Instructions on how to fit the two ROMs inside your BBC Microcomputer are supplied with the Second Processor. Installation is very simple, but if you would prefer not to fit the ROMs yourself, then your local dealer will do it for you.

    Technical data

    The 6502 Second Processor has a 64K Random Access Memory (RAM) which provides 60K bytes of RAM available for assembly language programs. The Second Processor operates at a clock rate of 3MHz.

    You will need a Model B BBC Microcomputer with a version 1.2 machine operating system, a colour or monochrome monitor (or television set), and a cassette recorder or a disc drive. If required, the version 1.2 MOS will be fitted to the BBC Microcomputer, free of charge, when the 6502 Second Processor is purchased.

    The unit measures approximately 205mm×345mm and has its own power supply.

    For futher details ask your nearest dealer or write to:

    Acorn Computers Limited 
    Fulbourn Road 
    Cherry Hinton 
    Cambridge CB1 4JN 

    AMP 06
    The British Broadcasting Corporation Microcomputer Z80 Second Processor

    The Z80® Second Processor is an extension unit which converts your British Broadcasting Corporation Microcomputer into a very powerful business tool. Supplied complete with a comprehensive package of business software, the Z80 Second Processor (when linked to you BBC* Microcomputer) offers computing power to rival that provided by machines costing twice as much.

    The BBC Microcomputer was designed to allow for second processors by incorporating Acorn's unique Tube interface. This provides a high speed data channel for the addition of a second processor. So connecting the Z80 Second Processor is simplicity itself.

    Complementary software

    Each purchaser will receive a collection of complementary software in addition to the Z80 Second Processor itself. The programs have been specially selected to suit a wide range of applications and will appeal particularly to business users, business educationalists, 'professional' home users (for example secretaries of golf clubs, housing associations, etc) and students of business studies.

    The software package includes:

  • A powerful word processor - MemoPlan.™
  • A personal database - FilePlan™. This can be combined with MemoPlan to provide automated mailing facilities.
  • A spreadsheet modelling program with integrated graphics - GraphPlan™
  • An integrated accounting system - Accountant.
  • A system generator which will help you to develop your own software - Nucleus, winner of the 1984 RITA Software Product of the Year Award.
  • A selection of additional programming languages - BBC BASIC, a complete program development system; Professional BASIC, an interpretive BASIC to allow access to a wide range of existing CP/M® programs; and CIS COBOL™, the leading microcomputer version of COBOL. Our CIS COBOL comes complete with ANIMATOR™ - a debugging tool, and FORMS2™ - an aid to writing interactive programs in CIS COBOL.
  • Access to business software

    Styled to be neatly positioned alongside the BBC Microcomputer, the Z80 Second Processor allows you to load a different operating system 0 CP/M 2.2. This is probably the most commonly used operating system for business micros in the world, so the library of software is vast. There are already something like 6,000 titles and the number is growing all the time.

    All the usual CP/M utilities are included in the Z80 Second Processor package and virtually any CP/M software will run on the Z80 Second Processor. If you are interested in a specific CP/M software package, ask your dealer to check that it is suitable for use with the Z80 Second Processor.

    Converting to CP/M will not in any way lead to a reduction in the facilities offered by your BBC Microcomputer.

    Technical data

    The Z80 Second Processor has a 64K Random Access Memory (RAM) which provides approximately 55K bytes of RAM available for user programs. This is often referred to as a 60K CP/M system. The Second Processor operates at a clock rate of 6MHz.

    The Z80 Second Processor incorporates Acorn's custom built integrated circuit known as the Tube. Using this chip concurrent tasks communicate asynchronously between two processors.

    The CP/M system, whilst being the industry standard, also allows full access to the BBC Microcomputer MOS.

    CP/M programs can use any one of three ways to control the display facilities:

  • Directly, by using the same codes as the BBC Microcomputer itself. All facilities are then available to the Z80 Second Processor, but programs will probably need to be specially written to use them.
  • Indirectly, by using a simple terminal emulator build into the Z80 Second Processor. Only some facilities are available, but existing CP/M programs should easily accommodate this form of screen control.
  • Machine independently, by using the GSX™ graphics extension to CP/M. Based on the international standard, GKS, GSX offers direct compatibility with other CP/M computers. There are now many new graphics applications being produced to run with GSX, and many more are expected in the future.
  • You will need a Model B BBC Microcomputer with a disc interface, a version 1.2 machine operating system, a colour or monochrome monitor or television set, a dual, 80 track disc drive, a suitable printer and connecting lead. If necessary, the version 1.2 MOS will be fitted to the BBC Microcomputer, free of charge, when the Z80 Second Processor is purchased.

    Each purchaser will receive a set of user guides, an additonal ROM for the BBC Microcomputer, and instructions on how to fir it. This ROM will also update the existing disc filing system and Econet® filing system. Your local dealer will fit the ROM if required.

    The unit measures approximately 205mm×345mm and has its own mains power supply.

    For futher details ask your nearest dealer or write to:

    Acorn Computers Limited
    Fulbourn Road
    Cherry Hinton
    Cambridge CB1 4JN

    The BBC Microcomputer System is designed, produced and distributed in the UK by Acorn Computers Limited. This description and specification is subject to change without notice.

    *British Broadcasting Corporation is abbreviated to BBC throughout the text.
    Z80 is a registered trademark of Zilog
    CP/M and GSX are registered trademarks of Digital Research Inc.
    MemoPlan, FilePlan and GraphPlan are trademarks of Chang Laboratories Inc.
    CIS COBOL, ANIMATOR and FORMS2 are trademarks of Micro Focus Limited
    Econet is a registered trademark of Acorn Computers Limited.

    AMP 08
    The Speech Synthesis and Cartridge ROM System for the BBC Microcomputer

    The BBC Microcomputer can be extended to include the ability to speak sounds and words from a vocabulary contained within a Word PHROM (Phrase Read Only Memory). This extension also provides the facility to enable cartridge ROMS to be plugged into the microcomputer via a socked to the left of the keyboard.

    Speech Synthesis

    The key items enabling the microcomputer to produce coherent speech are the Speech Processor and PHROM Integrated Circuits. The Speech Processor is based on the Linear Predictive Coding technique which provides a very compact encoding into a binary representation of speech information. The first PHROM to be made available is designated PHROM 'A'. The Speech Processor takes serial data provided by the PHROM Integrated circuit and converts it into audible "words" under the control of the main CPU. In addition to the PHROM fitted internally in the microcomputer, serial data can also be provided by Cartridge ROMs or from internal RAM. The PHROM 'A' currently fitted contains approximately 164 addressable words or word-parts with an English accent. A particular word is activated by means of extensions to the BBC Basic "SOUND" statement using channel -1.

    Cartridge ROM

    The Speech Processor provides the vital serial processing capability required by Cartridge ROMS. These ROMs, planned for later availability, plug into the microcomputer via the vacant area to the left of the keyboard. Further speech PHROMS are planned in Cartridge ROM format in addition to games and application programs.

    The Speech Synthesis/Cartridge ROM upgrade is only available fitted by an Authorised Service Centre and requires version 1.2 MOS (Machine Operating System) which will be fitted free by the Service Centre, if required, during this upgrade.

    A Speech System User Guide is included with the upgrade.

    Upgrage cost is £55 inc VAT, fitted.

    The BBC Microcomputer System is designed, produced and distributed in the UK by Acorn Computers Limited.

    Price and specification may change without notice.

    AMP 13

    The Acorn IEEE Interface for the BBC Microcomputer


    The Acorn IEEE Interface enables a British Broadcasting Corporation Microcomputer to control any scientific and technical equipment which conforms to the IEEE 488 standard.

    Together, the IEEE Interface and BBC Microcomputer provide computer control of IEEE488-compatible devices at a lower price than other systems - but without sacrificing any aspect of the IEEE488 standard. And, as an added bonus, Interface users have available to them the full power and versatility of the BBC Microcomputer.


    The IEEE Interface is provided in its own case, designed to match the BBC Microcomputer. It can be linked to a network of up to 14 separate IEEE488-compatible devices: oscilloscopes, voltmeters, logic analysers, spectrum analysers, function generators, frequency meters, and any of the many other devices that are available.

    When installed, the Interface automatically establishes the micro as the controlling device on the network. In addition, the micro can operate as a controller-talker or controller-listener and it can pass control to and from any other suitable device on the network. when not controlling the network the micro can operate as a talker or listener.

    Typical applications of the Interface are in experimental work in academic and industrial laboratories. For example, the micro might be programmed to instruct one device to generate input signals at a range of frequencies, and to accept measurements of the corresponding output signals from a second device.

    The advantages of computer-controlled operation over manual operation are speed, accuracy and repeatability. In addition, the data from the experiment are immediately available to the micro's analysis programs, giving almost instant results and allowing rapid comparison of the results of different tests.

    Many other applications of the Interface exist in the monitoring and control of scientific and industrial processes.


    Careful design of the Interface ensures that efficient hardware is matched by easy-to-use software.

    A Read Only Memory plugging into one of the BBC Microcomputer's spare ROM slots provides the IEEE Interface Filing System (IEEEFS). This is a set of plain English commands which the programmer uses to pass instructions from the micro to the devices on the network. The micro regards the IEEEFS as another filing system like disc or tape, so that the format of the program statements which address the IEEEFS will already be familiar to those with experience of the BBC Microcomputer. In addition, the straightforward nature of the commands enables full control of an IEEE488 network to be achieved without a detailed understanding of the operation of the interface.

    The IEEEFS commands can be incorporated into programs written in any of the high-level languages available on the BBC Microcomputer: BBC BASIC, 6502 Assembler and so on.

    Commands are available for all the functions included in the IEEE488 standard, including both serial and parallel polling, timeouts, and enabling and disabling of local control for all or individual devices.

    Full explanations of the IEEEFS commands, and examples of their use, are included in the User Guide supplied with the interface.


    The BBC Microcomputer/IEEE Interface combination provides more than just control of an IEEE network. When not being used with a network, or whilst two other devices on the network are communicating with each other, the usual range of facilities of the versatile BBC Microcomputer are available to the user.

    Its renowned colour graphics capabilities provide the ideal way of presenting experimental results in an instantly understandable form. A second processor can be connected for even faster processing and greater memory capacity. Or the micro can be linked into Acorn's Econet local area network, making control of and data from the IEEE488 system available to all the other micros on the network.

    The interface itself has an additional 1MHz bus connection, enabling it to be linked to any of the other interfaces which operate from this bus, such as Acorn's Teletext acquisition unit. Use of the IEEE Interface places no restrictions on the other applications of the BBC Microcomputer.


    Specification The Acorn IEE Interface enables full implementation of the IEEE Standard 488 - 1978. IEEE488 is also known as, and is equivalent to: IEC625-1 (in Europe) and GPIB or HP-IB (Hewlett Packard General Purpose Interface Bus).

    Configuration The Interface is a high-quality, double-sided, plated-through-hole printed circuit board, produced to BS9000. It is supplied in a robust case designed to match the BBC Microcomputer.

    Connections A cable and plug to IEEE488-1978 specification for connection to one IEEE488-compatible device. A ribbon cabble for connection to the BBC Microcomputer 1MHz expansion bus. A socket enabling connection of other 1MHz bus devices. A two-metre mains cable with fitted 13A square pin plug.

    Network configuration The Interface can support a network of up to 14 other IEEE488-compatible devices. Devices can be interconnected in a star or linear fashion. IEEE488 permits individual cable lengths of up to four metres, and a total cable length in a network of two metres per device with a maximum of 20 metres.

    Software provision The IEEE Interface Filing System (IEEEFS) is provided in a ROM which fits into one of the BBC Microcomputer's paged ROM slots.

    Software facilities Access to the IEEEFS commands is provided by the command *IEEE. The commands available (with standard IEEE488 mnemonics in brackets are:

    CLEAR                (IFC)  REMOTE DISABLE 
    DEVICE CLEAR         (DCL)  REMOTE ENABLE             (REN) 
    EXECUTE                     SELECTED DEVICE CLEAR     (SDC) 
    LISTEN               (LAG)  STATUS
    LOCAL LOCKOUT        (LLO)  TAKE CONTROL              (TCT) 
    PARALLEL POLL               TALK                      (TAG) 
      DISABLE            (PPD)  TIMEOUT OFF 
    PARALLEL POLL               TIMEOUT ON 
      ENABLE             (PPE)  TRANSFER 
    PARALLEL POLL               TRIGGER                   (GET) 
      REQUEST            (PPR)  UNLISTEN                  (UNL) 
    PARALELL POLL               UNTALK                    (UNT)
    Data transmission Data can be sent and received by the Interface in strings of up to 255 ASCII characters. The delimiting character defaults to line feed (ASCII code 10), but any other delimiting character or characters can be specified if required by a particular device. Longer strings of data can be transmitted in binary coded form. the Interface can instruct two devices to transfer data from one to the other without storing it in the BBC Microcomputer's memory, so freeing the computer for other tasks.

    Error Checking Comprehensive error checking facilities are provided. Bus errors and the state of the Interface are available to the user via a 32-bit status word.

    Power supply 220/240V AC, 50/60Hz.

    Documentation A 70-page User Guide containing full details of the IEEEFS commands and their use is supplied with the Interface.

    Dimensions (approx) Height×width×depth: 75×205×350mm.

    Temperature range 10º to 30ºC.

    Requirements The IEEE Interface system requires a BBC Microcomputer Model B with a series 1 MOS (Machine Operating System). The operating system is provided free if required.

    In this leaflet, the initials BBC stand for the British Broadcasting Corporation.

    The Acorn IEEE Interface is distributed in the UK by Acorn Computers Limited. Every effort is made to ensure that the information in this leaflet is correct, but we reserve the right to make alterations at any time. No responsibility is accepted for errors or omissions.

    Acorn Computers Limited
    Fulbourn Road
    Cherry Hinton
    Cambridge CB1 4JN

    AMP 14
    The Acorn Bitstik

    The Acorn Bitstik enables you to exploit the renowned graphics capabilities of the British Broadcasing Corporation Microcomputer to the full. with the Bitstik you can turn your graphics ideas into colourful reality in a matter of moments, and it provides the ideal introduction to the exciting world of computer aided design.


    The Bitstik system consists of a joystick and full supporting software. The joystick is a robust design which achieves precision without fiddliness. Its movement is smooth yet positive, and the distance of travel is carefully planned to combine accuracy with comfortable operation. It gives rotation as well as movement in the X and Y axes. Three pushbuttons conveiniently placed on the top of the joystic case are used in selecting functions from the screen menu, making the Bitstik completely independent of the BBC Microcomputer keyboard. After a short time you'll find the joystick becoming almost an extension of your hand so that your eyes need never leave the screen.


    The Bitstik can draw 'freehand' lines for you anywhere on the screen, following the movement of the joystick. Alternatively, it will automatically draw lines of the shape you choose: straight lines, curves, circles or arcs. These lines are first 'sketched' on the screen for you to accept or alter; you don't just have to imaging where they will go. For extra precision, the start and end of lines can be restricted to a grid of points. The spacing and angle of the grid are chosen by the user, allowing the construction of perfectly closed shapes or angles accurate to one minute of arc. Lines can be solid or selected from a range of dotted and broken types, and the size of the 'pen nib' can be varied enabling lines to be of any thickness.


    Lines can be drawn in three different colours, and shapes and backgrounds can be 'painted' with colours chosen from a palette containing four solid colours and 12 shades. The colours used can be selected from the full range made available by the BBC Microcomputer.

    Saving and retrieving

    Once a drawing has been created it can be stored by the Bitstik system on disc. Then it can be recalled at any time or included in any other drawing. Up to 48 different drawings can be stored on a single library disc. Once stored a drawing can include other stored drawings, and both lines and colours are stored. There is virtually no limit to the complexity of a stored drawing. The Bitstik uses a visual library system which displays miniature pictures of saved drawings, allowing immediate identification. A recalled drawing can be placed anywhere on screen, and can be made any size. It can be stretched, squashed, placed at an angle or completely reversed. And the same drawing can be repeated any number of times, enabling complex graphics to be built up from a few basic elements in minutes.


    Any part of the screen created using the Bitstik can be enlarged to the full screen size. This enlargement can be repeated again...and virtually unlimited magnification. the enlargement is not limited to the information shown on screen. If the detail you want to see falls outside the screen you can 'pan' in any direction across the enlarged drawing until you find the part you want. Lines and recalled drawings can be added to an enlarged screen in the normal way and are held by the system even if, on return to the original screen, the extra information is too small to be registered by the screen resolution.


    Text typed from the BBC Microcomputer keyboard can be added at any point on the screen and can be shrunk, enlarged, squashed, stretched or turned, just like a shape or drawing.


    The Bitstik is provided with an inbuilt 'dump' facility for printing screen images on the Acorn Spark-Jet black and white printer. Colours are represented by different types of shading.


    Despite its powerful and varied functions the Bitstik is extremely easy to use. Its sophisticated software facilities are listed on menus shown at the edge of the screen and are selected using the joystick. Colours and line types are chosen in a similar simple way, and the Bitstik is provided with a comprehensive User Guide.

    Technical details


    The Acorn Bitstik system comprises:
  • A precision three-axis joystick
  • An 80 track disc containing system master software, utilities and a sample library of drawings
  • A 2764 service ROM for fitting in the BBC Microcomputer containing the Bitstik graphics system
  • A comprehensive User Guide
  • Software facilities

  • Line: Draws a straight line between two selected points.
  • Circle: Draws a circle with a selected centre and radius
  • Arc: Draws an arc between two selected points with a selected centre and radius
  • Nib: Enables lines to be drawn to any width, in any of the selected colours, and to be dotted, dashed or shaded
  • Paint: Fills any area with colour
  • Trace: Allows freehand drawing, eg to trace round image superimposed on screen.
  • Erase: Deletes individual lines in reverse order
  • Find: Enables lines to be drawn to/from exact ends of other lines, centres of circles etc.
  • Text: Text can be added in any colour and at any size and rotation.
  • File to library: Saves drawings to disc library with visual catalogue
  • Copy from library: Retreives drawings from library, optionally with rotation, change of scale on X and/or Y axis reversal.
  • Move: Moves element copied from library to different part of screen
  • Duplicate: Repeats element copied from library
  • Swap: Replaces an element copied from library by another library element
  • Zoom: Enlarges part of the screen to full screen sive. This operation can be repeated more than 40 times on the same drawing.
  • Pan: Moves screen across enlarged drawing.
  • Page: Returns from zoom to original drawing.
  • Angle: Locks angles at which lines can be drawn. Two pairs of angles can be chosen.
  • Orthogonal: Locks angles at which lines can be drawn to 0° and 90°.
  • Normal/tangent: After drawing arc, locks angles normal to and at tangent to arc.
  • Grid: Locks start and end of lines and centres of circles to points on a grid. Three grids available: 8×8 and 8×6 pixels and one user definable. Grids can be angled.
  • Wipe: Clears screen.
  • Software utilities

    Bit images of screen can be saved and reloaded.
    Zoom level and location can be saved and reloaded.
    Screen image can be dumped to Acorn JP101 Spark-Jet printer.
    Menus can be removed to expand image to full screen size.


    Drawing: Four colours (three foreground, one background)
    Painting: 16 colours (four colours and 12 composites of these).

    The four drawing and solid painting colours can be selected from any of the BBC Microcomputer's palette of 16 colours (including flashing colours).


    Unlimited stored resolution.
    Display resolution limited only by screen or plotter used.
    Angular resolution: One minute of arc.


  • Controls: Three-axis joystick (X, Y and rotation). Three push buttons for menu-driven option selection.
  • Indicator: Power LED.
  • Material: Injection moulded plastic.
  • Colour: BBC Microcomputer cream.
  • Signal connection: Ribbon cable to BBC Microcomputer analogue port with connector supplied.
  • Power supply: From BBC Microcomputer.
  • Temperature range: 10º to 35ºC
  • Dimensions: (H×W×D): 130×110×116mm (approx).
  • Weight: 0.5kg (approx).
  • Six month guarantee.
  • Requirements:

    The Acorn Bitstik system requires the following additional equipment:

    BBC Model B Microcomputer with disc interface and series 1 operating system (operating system provided free if required).
    Acorn 6502 second processor system.
    Dual disc drive (80 track).
    Colour monitor (Acorn RGB monitor recommended).
    Acorn JP101 Spark-Jet printer (optional).

    Order code: ANF04