spectrum graphics - OpenLibra

and summaries ail included in
such a way as to show that a
great deal of thought went in to
its organistation and produc
tion. Text Mode and UDG Mode
are fascinating and easy to work
with. Text and characters ap
pear at the bottom of the screen
and can then be 'picked up' and
positioned anywhere you want
them in vour picture or design.
Then, just when you will probably
be ready to move on to
more ambitious projects,
graphically, Lightmagic proves
its magic again. The program
also offers a facility called UDG
Designer for the creation and
editing of your own graphics
characters which you can then
use in your own pictures and
programs. The facility for Com
Dressing pictures and saving
memory is offered in the COMP-
SCREEN option. This is loaded
separately from the cassette.
It's there in other words, when
you need it. Later rather than
sooner probably.
Alongside Lightmagic, not
for comparison, but because for
me they have the same feel
about them, might come
Leonard, from CREATIVE
SPARKS. Again, full marks for
the manual. Manuals ought to
be user friendly as the software I
think and in the case of Leonardo
both are in fact true. I don't
hesitate to recommend it as an
excellent starter pack which is
then capable of extending your
own abilities as you learn to use
it. A preliminary review of
Leonardo appeared in the last
issue of ZXC.
This is a good place to sug
gest that anyone who is into
graphics or who wants to get
started should get out and about
into the shops to make their own
evaluations. Failing that use the
information in this article to put
pen to paper and write off and
ask for details of packages from
the manufacturers.
Lightpens
I've had most success to date,
with the package from
Dk'tronics. The pen itself is
rather like a biro or felt tip pen. It
is attatched by a wire to a con
trol interface which of course
comes with the package. The interface
is plugged into the back
of ihe Spectrum. A program on
cassette is included.
The glass screen of your
monitor is the working area and
drawing surface, so some consideration
has to be given as to
whether this is the' way you
want to work. Then there are
practical aspects such as the
41 ZX COMPUTING DECEMBER/JANUARY 1985
distance of your screen from
your keyboard, and the fact thai
you have to work on a perpendicular
'face'. The height of the
screen is therefore important if
you do not want to suffer from
muscle fatigue in your drawing
arm.
Lightpens give you a physical
contact and interaction with
your drawing surface if that is
important. Calibrating the pen
each time may prove a chore,
but after that it's plainsailing
within the limitations of the
power of the program. Again it's
a good way of getting started or
the very basics of graphics, of
getting into the picture as it
were. Sensibly introduced in the
classroom it could be useful aid
and introduction for children in
an educational context. It is
limited though in its potential for
advanced or complex screen
designs. Graphics Tablets give
you similar physical point of con
tact with your drawing-surface.
This time it is horizontal and
again a 'pen' is used. There's a
review of the Saga Graphics Pad
in this issue. So when you are
ready look it up. They certainly
take you further than the
lightpen. But then you pay a lot
more for the facilities they offer.
Now for something almost
completely different, the
Sinclair LOGO pack. Another ex
cellent starter, but as I have
hinted, quite different.
This pack has very obvious
educational applications and for
very young children. The founding
father of the LOGO
language iniended it as a
language for children which
would develop logical thinking,
introduce young minds to computer
programming and have
very definite terms of reference
for the teaching and develop
ment of mathematical concepts.
Drawing is achieved by
moving a small graphics 'turtle'
a triangle around the
screen. This is done by sending
through ihe computer com
mands known as Primitive Procedures
(mostly single words
and abbreviations of those
words). Your sense of direction
needs to be accurate and
formulated mathematically. Once
you have established pro
cedures for drawing, say, a
square, this group of procedures
can be assigned a single word or
name which LOGO will then
understand as a command to
repeat the whole set ol pro
cedures.
The emphasis or bias is fundamentally
mathematical,
arithmetical or geometric. You
do not just learn to draw a
square, you also learn what
makes a square what it is and
from there the difference bet
ween a square and a rectangle or
a parallelogram.
It is a language itself, apart
from BASIC. Hence learning to
use it is learning to program a
computer in another language.
The graphic aspect being
displayed on the screen is part of
the incentive and motivation for
progressing with the new
language.
Two fairly weighty and com
prehensile books or manuals
are pan of the pack. The firsi
book deals exclusively with Tur
tie Graphics and is an absorbing
and refreshingly different kind of
programming experience. The
second book acts as a reference
manual for Sinclair LOGO, The
growth, use and development of
LOGO by Spectrum owners,
especially in schools will, I think,
be affected by the cost factor.
When DREAM SOFTWARE
released Computer Aided Designer,
my own children had not had their
Spectrum for long. They, tike me
were exploring the full graphics
potential of the machine when
C. A.D. turned up and kept us
enthralled for days. Now, still an
old favourite, I would recommend
it as another in the
'Starter' category. With very
obvious educational values and
as a springboard for more am
bitious projects later in Design.
The manual is simple and
very straightforward —
alphabetically leading you
through the twenty seven com
mands available in the program.
Some forty custom shaped
graphics, UDGs can be designed.
By giving precise
measurements most geometric
shapes can be drawn, filled and
so on. It remains impressive
after all this time, and the potential
for drawing in 3 D is considerable.
Similarly, another old
favourite, VU-3D from PSION.
This has the added and appeal of
enabling the viewer to move
around the object in 3D.
Graphics and Design, pure and
simple. High resolution colour
and an incredible understanding
of perspectives are real bonuses
with this program.
Future designers in the Air
craft or for that matter almost
any other Industry, may have
started young with something
like C.A.D. or VU 3D.
I doubt if they would have
been able to afford the RD
Digital Tracer, from RD
Laboratories. This is closer to an
instrument than anything else
I've come across in graphics and
design hardware and software
for the Spectrum
It comes in two versions, the
Standard and the Professional.
Both are fairly highly technical
and sophisticated tools. The
Tracer consists of a short fixed
arm and pivot from which ex
tends a drawing arm hinged at
the centre with another floating
pivot which moves across your
drawing surface area.
The arm is connected to the
computer by a length of cable
via an interface plugged into the
rear port of the Spectrum. A
cardboard template and
transparent grid overlay are included
for calibration purposes,
the tracer is a precision instrument.
The software cassette
contains five programs. The
usual options are offered in the
first, plotting single points, con
struction of basic geometric
ligures, filling, hatching, change
of ink, border, paper colour, ad
ding text, UDGs and so on.
The display image can be
moved up, down, and from side
t o s ide, sea led u p a n< I d ow n, a nd
reversed. Multiple screen images
including images at dif
ferent scales and at different
positions can be achieved. By
adding other BASIC routines
and software, ihe Tracer's
capabilities can be extended into
the field of statistical analysis.
This immediately puts the
Tracer into a specialist Graphics
and Display category. Although
the Tracer can be used with the
ZX81 andl 6 K Spectrum, its full
potential can only really be
developed on the 48 K and then
only by competent program
mers. It's a versatile instrument
for the specialist.
It's the season of Good will
and all thai, so why not give a
last mention for all whose
speciality is Games Designing.
It's been around for a while, but
standing the test of time in lots
of ways. I'm referring of course
to the High level User Friendly
Real time Games Designer from
Melbourne House. Or as it is
more commonly known, HURG.
Still a powerful program and
a very good manual. How did
they do it in those all time greats
like Pacman, Donkey Kong and
Space Invaders? H U.R.G. will
tell you how.
It's a pretty good list of
graphics goodies and that other
seasonal expression comes to
mind. 'There's something here
for everyone.' You have no ex
cuse for not knowing how and
from whom in Spectrum
Graphics, Just how to enjoy the
graphics power behind those
I
buttons.