Acorn Atom Technical Manual
The Atom Technical Manual is Acorn Computers' own construction and reference manual for the Acorn Atom, Issue 2, October 1980, copyright Acorn Computers Ltd 1980. 22 pages. The scan carries a text layer and is searchable.
The Atom was sold both as a kit and assembled, and this manual is written for the person building it: Acorn's stated purpose is "the information needed in order to construct the ATOM kit and add any of the extensions". Use of the machine is covered elsewhere, in the book Atomic Theory and Practice.
Contents
[edit | edit source]Acorn's own contents list, with printed page numbers:
- Introduction — 3
- Construction procedure — 4: parts list 6, layout diagrams 8, TV/video monitor 13, power supply 13, switching on 14, tape recorder 14, output ports 15
- Circuit description — 16
- Block diagram — 18
- Memory map — 20
- Expanding the ATOM — 21: lower text space extension 21, video graphics extension 21, floating point extension 22, versatile interface adaptor 22, printer interface 23, bus buffers 23, Eurocard extension 23, other extensions 23
What it settles
[edit | edit source]- The parts list and layout diagrams on pages 6–12 are the source for Atom component designators and values, and for which positions are populated in which configuration — the Atom's expandability means many sockets and positions are empty on any given board.
- Acorn warns in the construction chapter that substitute components may be supplied where there were supply difficulties, giving "100 nF capacitors may replace 47 nF parts" as its own example. A board that does not match the parts list exactly is not necessarily modified.
- The manual explains Acorn's three-digit capacitor marking: the first two digits are the first two digits of the value and the third is the number of zeros. This is worth knowing before condemning a part as the wrong value.
What this manual does not contain
[edit | edit source]- No fault-finding procedures and no diagnostic flowcharts. It is a construction manual; Acorn's answer to a faulty Atom was to return it to Cambridge for repair, and the manual quotes the charge for doing so.
- No power supply component values. The power supply section describes what the Atom needs and how to connect it, not what is inside it.
- No circuit diagram in this volume — the circuit is described in prose and by block diagram.
- No coverage of the Acorn System 1 range beyond the note that the Atom is bus-compatible with Acorn's 6502 Eurocards.
Pages that cite this document
[edit | edit source]- Acorn Atom · Acorn Atom General Maintenance · Acorn Atom Troubleshooting Guide · Acorn Atom Capacitor Replacement Guide
Download here: Acorn Atom Technical Manual.pdf