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MAKE-A-CHIP by Incognito Software Ltd.
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Document created by rstuart@ukonline.co.uk on 16th Oct 1999 for
World of Spectrum: http://www.worldofspectrum.org/

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Sinclair  ZX Spectrum Make-a-Chip
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Make-a-Chip teaches you the basic elements of circuit design, shows you how they
fit together, and then lets you design and test your own circuits.

When you have designed a circuit, you can give it inputs and outputs and your ZX
Spectrum will check it for you. Then it will run it, or tell you what's wrong so
that you can modify it.

Make-a-Chip is a fascinating way of finding out how a computer works.

 Registered Trade Marks of Sinclair Research Ltd.
 Copyright 1983 Incognito Software Ltd.
Published by Sinclair Research Ltd, 25 Willis Road, Cambridge, CB1 2AQ.
Made in UK.


Introduction
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MAKE-A-CHIP enables you to explore some aspects of how your computer works. A
computer is made up from a large number of electronic circuits. MAKE-A-CHIP will
tell you about simple electronic circuits and the basic elements of circuit
design, and show you examples of some circuits which are found inside your ZX
Spectrum. The program also enables you to try your hand at circuit design. You
can create your own circuits by combining the basic units, and then see how your
circuits would work.


Operating Instructions
----------------------

Put the tape into your tape recorder and type the command LOAD "". Start your
cassette player and then press the ENTER key. The program will load in five
stages and then start running automatically.

If you stop the program and later want to start it again without reloading, give
the command GOTO 1.

In no circumstances give the commands RUN or CLEAR.


Using the Program
-----------------

The program is in three parts. The first tells you about the basic elements of
circuit design, the second shows you example circuits, and the third allows you
to combine basic circuit elements and try out some of your own circuit designs.

When you have loaded the program, select your starting point. We recommend that
the first time you run the program, you try each part in turn.

You can return to the main menu by pressing Q at any point when the computer
asks you to 'press any key to continue'.


1 Learn

This part of the program introduces you to the basics of circuit design, leading
on to the five basic circuit elements, or 'gates' as they are called in computer
terminology. A gate has a number of inputs - restricted to two in this program -
and an output. The value of the output will depend on the values of the inputs.
You will find out about AND, OR, NOT, NAND and NOR gates.


2 Example

This part of the program shows you how to connect gates to make more complex
circuits.

You will see how every type of gate can be made by combinations of just one type
of gate. You will then find out about combining gates to make a circuit which
will remember information, as you would find in a computer store or register.


3 Experiment

This part of the program enables you to design your own circuits. Your circuit
can contain up to 12 gates (AND, OR, NOT, NAND and NOR), four inputs and four
outputs. At any stage you can go back to LEARN to see what a particular gate
does, go back to EXAMPLE, or print your circuit.

When you have designed your circuit, you may give it some inputs and outputs.
Your ZX Spectrum will then check that the circuit is valid; if it is not, it
will show you what is wrong and you can correct it. When your circuit is valid,
you can 'run' it, asking your Spectrum what the outputs would be for various
input combinations. Alternatively, you can try to work out the outputs for a
particular input combination, and your Spectrum will tell you if you are right.
You can make a permanent record of your design by printing the circuit, showing
the inputs and outputs.

Once you have run your circuit, you can then try running it again with different
input or feedback values, modify it by adding more gates, or design a fresh
circuit.

You can switch between the three main parts of the program at any time without
losing the circuit you are developing.




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User Manual for Make-A-Chip
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First published in 1983 by Sinclair Research Limited
25 Willis Road, Cambridge, CB1 2AQ England

ISBN 0 85016 002 3

 Copyright Incognito Software Ltd 1983

All rights reserved. No part of this program packaging or documentation may be
reproduced in any form. Unauthorised copying, hiring, lending, or sale and
repurchase prohibited.

Printed in UK
