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Publisher & Editor-in-Chief
Leo Simpson, B.Bus., FAICD
Editor
Greg Swain, B.Sc.(Hons.)
Technical Staff
John Clarke, B.E.(Elec.)
Robert Flynn
Rick Walters
Reader Services
Ann Jenkinson
Advertising Manager
Brendon Sheridan
Phone (03) 9720 9198
Mobile 0416 009 217
Regular Contributors
Brendan Akhurst
Garry Cratt, VK2YBX
Julian Edgar, Dip.T.(Sec.), B.Ed
John Hill
Mike Sheriff, B.Sc, VK2YFK
Philip Watson, MIREE, VK2ZPW
Bob Young
Photography
Glenn A. Keep
SILICON CHIP is published 12 times
a year by Silicon Chip Publications
Pty Ltd. A.C.N. 003 205 490. All
material copyright ©. No part of
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PUBLISHER'S LETTER
Putting those old
computers to work
This month we have three computer-related
articles which emphasise the usefulness of older
computers. The first is the article on networking,
starting on page 4. This was prompted by an application in our office but is typical of situations
which occur in small offices or homes with more
than one computer. It is a boon when printing
from more than one computer is a common
requirement.
The second article is the computer controlled
power supply which starts on page 56. This is an interesting project because it
can be built as a conventional power supply or as one which is under full control of a computer. Such a supply can be turned on and off or the voltage varied
automatically. As well, the current drain can be recorded, which could be useful
in some applications.
The third article relates to the Digi-Temp which can monitor up to eight temperature sensors in different locations via two wires. Again, it can be built as a
self-contained unit or it can be hooked up to a computer for logging applications.
It starts on page 80. On the same theme, next month we will publish a computer
controlled message board.
None of these applications require the latest Pentium-based machine but can use
older 286, 386 or 486-based machines. They emphasise that the older machines
still have a multitude of uses and don’t need to gather dust in the back of a closet.
We are very conscious of the market pressures to upgrade computers, particularly
with the advent of Windows 95 software which is so hungry for RAM and hard
disc space. These pressures are bad enough in a commercial environment where
it is almost mandatory to obtain the latest upgrades of every software package.
Where it does seem unnecessary is with the tens of thousands of home machines
which are seldom used to even a fraction of their potential.
This was driven home to me just recently concerning the computer of one of
my close relatives. She has a 100MHz Pentium machine with a large hard disc,
quad-speed CD ROM, sound card and all the bells and whistles. It is only 12
months old and the video monitor has just failed. However, instead of getting
the monitor repaired, she is seriously considering replacing the system with a
166MHz Pentium machine, partly because she has had a few hassles with the
Windows 95 setup and the sound card.
I was flabbergasted, as you can imagine. For probably less than $100 the monitor
could be repaired and a few hours or so spent optimising the Windows 95 setup
would be required to make it do all she could want. The difference in speed in
upgrading to a 166MHz machine would be marginal – for much of the time it is
merely used to play games. But she was being swayed by the market hype for the
new machines. Such an outlook is extremely wasteful and yet all too common.
Leo Simpson
ISSN 1030-2662
WARNING!
SILICON CHIP magazine regularly describes projects which employ a mains power supply or produce high voltage. All such projects should
be considered dangerous or even lethal if not used safely. Readers are warned that high voltage wiring should be carried out according to the
instructions in the articles. When working on these projects use extreme care to ensure that you do not accidentally come into contact with
mains AC voltages or high voltage DC. If you are not confident about working with projects employing mains voltages or other high voltages,
you are advised not to attempt work on them. Silicon Chip Publications Pty Ltd disclaims any liability for damages should anyone be killed
or injured while working on a project or circuit described in any issue of SILICON CHIP magazine. Devices or circuits described in SILICON
CHIP may be covered by patents. SILICON CHIP disclaims any liability for the infringement of such patents by the manufacturing or selling of
any such equipment. SILICON CHIP also disclaims any liability for projects which are used in such a way as to infringe relevant government
regulations and by-laws.
Advertisers are warned that they are responsible for the content of all advertisements and that they must conform to the Trade Practices Act
1974 or as subsequently amended and to any governmental regulations which are applicable.
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