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^ m HARDWARE —<br />
The Perfect<br />
Keyboard<br />
John wase discusses how to customize<br />
your keyboard.<br />
It was this lady on the Oxford<br />
train. She was telling me how<br />
she was involved in a charity<br />
which deals with handicapped<br />
children's reading problems.<br />
'Yes,' she said 'we've got a<br />
Spectrum and like it very much;<br />
it's inexpensive and so easy to<br />
use'. I thought about that<br />
several times in the following<br />
week you know, she's right. I<br />
suppose that's why I keep adding<br />
bits onto mine essentially<br />
it's a basic, inexpensive and<br />
rather nice machine, even if you<br />
can't type with it. That was my<br />
problem when I first wanted to<br />
use it as a word-processor. So I<br />
seized and read as many add-on<br />
keyboard reviews as I could.<br />
Some of these are listed below.<br />
The list is by no means exhaustive.<br />
Several of them mention<br />
touch-typing being possible<br />
for a number of keyboards, but<br />
essentially this is just not true.<br />
Let's look why. . .<br />
Owerty. . .<br />
When you learn to touch-type<br />
the 'home' keys for the left hand<br />
are ASDF and those for the right<br />
hand are JKL;. Each of the four<br />
fingers thus rests on a key. The<br />
index (first finger! is also used<br />
for G (left hand) and H {right<br />
hand! respectively. To access<br />
the rows above and below, the<br />
hands move up and a little left or<br />
down and a little right.<br />
To convert the keys accessed<br />
by the left hand to capitals or<br />
equivalent, the shift key at the<br />
other end of the board is<br />
depressed, using the little finger<br />
of the right hand. And vice versa.<br />
So, to get any capitals properly,<br />
you need a shift key at<br />
each end of the bottom line,<br />
symmetrically placed, and<br />
situated conveniently for the little<br />
finger of either hand. Exit<br />
most add-on keyboards 'recommend<br />
for touch typing'.<br />
However, worse is to follow.<br />
The Spectrum was designed<br />
with the minimum number of<br />
figure 1 DK Tronics keyboard<br />
keys. A QWERTY keyboard has<br />
semicolon as the 'home' key (lit<br />
tie finger, right hand sidel, and a<br />
'single entry' full stop and com<br />
ma on the bottom line. These are<br />
missing on many add-on<br />
keyboards, but it is very difficult<br />
to touch type without, at any<br />
rate, the full stop and comma.<br />
Finally, because each key has<br />
to be used for much more than<br />
just lower case and caps, additional<br />
symbols are obtained<br />
through symbol shift, through<br />
extended mode, (caps shift and<br />
symbol shift), and through<br />
symbol shifted extended mode.<br />
A few of these are needed for<br />
normal typing, (e.g '!'), and<br />
Tasword uses double-shift for<br />
some control characters. So you<br />
must have a symbol shift at each<br />
end, again, preferably symmetrically<br />
placed and operated<br />
by the little finger, (like ihe caps<br />
shift!. Oh, and of course you<br />
need a space-bar<br />
Membrane Misery<br />
Well, when I looked, I could find<br />
no keyboard that fulfilled all<br />
these criteria. So I needed one<br />
that I could modify. This cuts<br />
down the choices bit, too! if you<br />
don't happen to have a joystick,<br />
you will know that overenthusiastic<br />
pounding of the<br />
cursor buttons eventually does<br />
them in. If you then prise apart<br />
the Spectrum case in your<br />
fury,you will find the (damaged)<br />
membrane. This consists of<br />
three plastic sheets glued<br />
together. The top one and bottom<br />
one have circuits printed in<br />
their inner surfaces; the middle<br />
one is blank, but the holes cut<br />
where the circuits cross, corresponding<br />
with the rubber but-<br />
tons above. So the two outer<br />
pieces of membrane are forced<br />
together when the button is<br />
pressed, making the appropriate<br />
contact. This principle is also used<br />
in some add-on keyboards,<br />
(the Saga Emperor 1 for instance).<br />
And, because of this<br />
membrane problem, they are<br />
very difficult to modify; to<br />
modify a key-board, it must<br />
essentially consist of separate<br />
keys mounted on a circuit board.<br />
Padding along<br />
As far as I was concerned, 1 had<br />
one additional criterion to meet,<br />
I often have to enter quantities<br />
of numeric data, either as tables<br />
in the text,or as a tabular<br />
material for calculations. So, for<br />
me a numeric pad was particular<br />
useful.<br />
At the time I was buying,<br />
there were far fewer keyboards<br />
available than now, and I recall<br />
considering two. Transform's<br />
was around C70 whilst DK<br />
Tronics new space-bar board<br />
was around £45 (it's now<br />
nearer C30). Both of these have<br />
separate keys. Those on the<br />
Transform board are of the<br />
plated-contact sort whilst those<br />
on the DK'Tronics board are of<br />
the cheaper individual<br />
membrane-deforming type.<br />
These are quite good enough for<br />
many purposes, and the price<br />
was attractive. So I bought a<br />
standard DK'Tronics board; this<br />
50 ZX COMPUTING DECEMBER JANUARY 1985
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