The Atom was Acorn's first computer to be aimed squarely at the home market.

The Acorn Atom was a home computer made by Acorn Computers Ltd from 1981 to 1983 when it was replaced by the BBC Micro (originally Proton) and later the Acorn Electron. Download high resolution version (883x480, 51 KB) Acorn Atom File links The following pages link to this file: Acorn Atom Allen Boothroyd Categories: 8BS images ... Download high resolution version (883x480, 51 KB) Acorn Atom File links The following pages link to this file: Acorn Atom Allen Boothroyd Categories: 8BS images ... Acorn Computers Ltd. ... TRS-80 Color Computer II The home computer is a consumer-friendly word for the second generation of microcomputers (the technical term that was previously used), entering the market in 1977 and becoming common during the 1980s. ... Acorn Computers Ltd. ... 1981 (MCMLXXXI) was a common year starting on Thursday of the Gregorian calendar. ... 1983 (MCMLXXXIII) was a common year starting on Saturday of the Gregorian calendar. ... The BBC Micro, affectionately known as the Beeb, was an early home computer. ... The Acorn Electron Acorn Electron BASIC - the first thing displayed when an unexpanded Electron is switched on The Acorn Electron was a budget version of the BBC Micro educational/home computer made by Acorn Computers Ltd. ...

The Atom was a progression of the MOS Technology 6502 based machines that the company had been making from 1979. The Atom was a cut-down Acorn System 3 without a disk drive but with an integral keyboard and cassette tape interface, sold in either kit or complete form. In 1982 it was priced between £120 in kit form, £170 ready assembled, to over £200 for the fully expanded version with 12kB of RAM and the floating point extension ROM. MOS Technology, Inc. ... The MOS Technology 6502 is an 8-bit microprocessor designed by MOS Technology in 1975. ... This page refers to the year 1979. ... The System 3 was a home computer produced by Acorn Computers from 1980. ... 1982 (MCMLXXXII) was a common year starting on Friday of the Gregorian calendar. ... GBP may be: short for Game Boy Player the ISO currency code for the British Pound Sterling. ... A kilobyte (derived from the SI prefix kilo-, meaning 1000) is a unit of information or computer storage equal to either 1024 or 1000 bytes. ... Sharma Ram (disambiguation) Ram Sharma is an amazing, talented teenager that lives in Canada His talents include rapping, comedy, and cooking He is bound to success! ... Read-only memory (ROM) is a class of storage media used in computers and other electronic devices. ...

The minimum Atom had 2kB of RAM and 8kB of ROM, with a fully loaded machine having 12kB of each. An additional floating point ROM was also available. The 12kB of RAM was divided between 6kB available for programs and 6kb for the high resolution graphics. In practice around 1kB of the lower memory was lost to variable storage of the 27 variables, and zero page memory used by the operating system. If high resolution graphics were not required then 5 1/2kB of the upper memory could be used for program storage. Sharma Ram (disambiguation) Ram Sharma is an amazing, talented teenager that lives in Canada His talents include rapping, comedy, and cooking He is bound to success! ... Read-only memory (ROM) is a class of storage media used in computers and other electronic devices. ... A floating-point number is a digital representation for a number in a certain subset of the rational numbers, and is often used to approximate an arbitrary real number on a computer. ... Read-only memory (ROM) is a class of storage media used in computers and other electronic devices. ... Sharma Ram (disambiguation) Ram Sharma is an amazing, talented teenager that lives in Canada His talents include rapping, comedy, and cooking He is bound to success! ...

It had a MC6847 VDU video chip, allowing for text or two-colour graphics modes. It could be connected to a TV or modified to output to a video monitor. Basic video memory was 1 kbyte but could be expanded to 6 kbyte. A PAL colour card was also available. Six video modes were available, with resolutions from 64x64 in 4 colours, up to 256 x 192 in monochrome. At the time 256 x 192 was considered to be high resolution. PAL, short for phase-alternating line, phase alternation by line or phase alternation line, is a colour encoding system used in broadcast television systems in large parts of the world. ...

It had built-in BASIC (Atom BASIC), although in an idiosyncratic version, which included indirection operators (similar to PEEK and POKE) for bytes and words (4 bytes). Assembly code could be included within a BASIC program, assembled during program execution and then executed. BASIC (Beginners All-purpose Symbolic Instruction Code) is a family of high-level programming languages. ... In computing, PEEK is a BASIC programming language function used for reading the contents of a memory cell at a specified address. ...

The manual for the Atom was called Atomic theory and practice

The Acorn LAN, Econet, was first configured on the Atom. A local area network (LAN) is a computer network covering a small local area, like a home, office, or small group of buildings such as a home, office, or college. ... Econet was a proprietary local area network used on Acorn computers. ...

The case was designed by industrial designer Allen Boothroyd of Cambridge Product Design Ltd. Allen Boothroyd is an industrial designer. ...

Memory Map

The following is the memory map for the Atom (from 1). Shaded areas indicate those present on the minimal system. The Atom was Acorns first computer to be aimed squarely at the home market. ...

Specifications

• CPU: MOS Technology 6502
• Speed: 1 MHz
• RAM: 2 kB, expandable to 12 kB
• ROM: 8 kB, expandable to 12kB with various Acorn and 3rd party ROMs
• Sound: 1 channel, integral loudspeaker
• Size: 381 x 241 x 64 mm
• I/O Ports: Computer Users Tape Standard (CUTS) interface, TV connector, Centronics parallel printer
• Storage: Kansas City standard audio cassette interface
• Power: 8 volts unregulated DC, providing 5 volts regulated inside the Atom

Note the Acorn 8V power supply was only rated to 1.5 amps, which was not enough for an Atom with fully-populated RAM sockets. The Atom's internal regulators also got uncomfortably hot. Therefore some Atom enthusiasts removed and by-passed the internal regulators and powered their Atoms from an external 5V regulated power supply. Three amps were typically needed for a fully-populated Atom. Intel 80486DX2 microprocessor in a ceramic PGA package A central processing unit (CPU), or sometimes simply processor, is the component in a digital computer that interprets instructions and processes data contained in software. ... The MOS Technology 6502 is an 8-bit microprocessor designed by MOS Technology in 1975. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Read-only memory (ROM) is a class of storage media used in computers and other electronic devices. ... The Kansas City standard (abbreviated KCS) for storage of data on an ordinary compact audio cassette was also known as the BYTE standard or the CUTS (Processor Technology Computer Users Tape Standard). ... Centronics logo 23 June 1986 Centronics logo 1971 Centronics Data Computer Corporation was a pioneering American manufacturer of computer printers, now remembered only for the parallel interface that bears their name. ... The Kansas City standard (abbreviated KCS) for storage of digital (micro)computer data on an ordinary compact audio cassette is also known as the BYTE standard, from its connection with BYTE magazine, or the Processor Technology CUTS (PT Computer Users Tape Standard). ...

There was no de-facto standard for external 5V connection, but using the same 7-pin DIN connectors as the Atari 800XL allowed the Atari power supply to drive low-power (up to 1.5A) Atoms.

References

1. Atomic Theory and Practice

External links

• http://www.xs4all.nl/~fjkraan/comp/atom/index.html
• http://www.howell1964.freeserve.co.uk/Acorn/Atom/Atom.htm
• http://home.wanadoo.nl/hhaydn/index-uk.html