the success of his two previous computers, the ZX-80 and particularly the
ZX-81, in April 1982 Sir Clive Sinclair presents the ZX-Spectrum. For
the first time, a computer with high-resolution graphics, colors, sound
and 48k RAM was sold under 25£. Once more Sinclair revolutionized
the microcomputer industry with new standards.
the launch of the Spectrum, many other microcomputer manufacturers were
forced to reduce their prices, and 17
months after the release of the Spectrum, the sales already reached 1
million units !
first saw the ZX Spectrum as an enhancement of the ZX-81, but it is much
:: BLACK IS BEAUTIFUL
is really great: all black with a rainbow at the bottom right.
keyboard is very special: rubber keys with a load of colorful inscriptions
on them. I even think that the ZX owns the-number-of-inscriptions-on-one-key
world record: up to six ! The "3" key for example, is
also used for the Basic statement LINE, the TRUE VIDEO mode,
the MAGENTA color, the "#" sign and a semi-graphic
symbol ! Impressive isn't it?
but not very practical. Ok, you can't make typing errors, but it's soooo
slow... Anyway, since then many manufacturers adopted this type of keys.
is quite small and you could take it with one hand.
:: THE SINCLAIR BASIC
Basic is special and all the statements are entered word by word using
the inscriptions on the keys.
There is absolutely no way to type those statements letter by letter,
just like with the ZX-81.
screen is divided in two parts : 22 lines used to display the program
listing and 2 lines at the bottom to enter the statements... quite unusual,
except for Sinclair fans. As you enter the Basic statements each new line
is analysed and if there's an error, the ZX prompts you to correct it.
is a degree of compatibility between the ZX-81 and the ZX-Spectrum Basics
as the ZX-81 Basic is a sub-set of the Spectrum's one.
The best feature of the Spectrum is its graphic possibilities.
With 256 x 192 pixels, it was one of the highest resolutions for a
of its range in 1982. LINE and CIRCLE statements are available, as well
as 21 semi-graphic symbols and user-definable characters. But unfortunately,
colors are limited to 8 x 8 pixels areas, that is to say that you can
only specify 1 ink color and 1 paper color per 8 x 8 pixels squares. This
is very important to understand the look and feel of most of the Speccy
But the greatest drawback is the sound possibilities. There's only a poor beeper
by the BEEP statement...
However, in assembly one could do digitized sound, and some guy even wrote a demo which
produced four channel sound on that shitty beeper. Of course it
wasn't real 4 channel, but it satisfied ears.
is based upon the classic Z80A microprocessor, a quicker version of the
transmission is very reliable (hello Oric) with a transmission rate of
A lot of hardware has been developed for the ZX-Spectrum. You
could find almost anything you wanted for your Speccy. The most innovative extension was maybe
the Sinclair Microdrives which were small mass-storage device using tiny
cartridges with endless magnetic tapes. Each cartridge can store about
85k. This is not fantastic, but it was a good and cheap alternative
to far more expensive disk drives. These microdrives, slightly modified,
were later used with the Sinclair QL.
was surely the most cloned microcomputer in the world ! Apart from the official
clones like the Timex 2048 & 2068 sold in the USA, there have been
many illegal compatible systems sold especially in the Far East, the old
communist area as we say.
:: A NEW MODEL : THE SPECTRUM+
the Spectrum is replaced by the Spectrum + which is only a Spectrum with
a new look: the rainbow is smaller and the design is more "squarish".
Underneath you can find two small "feet" to tilt the keyboard just like
the brand new PCs ! The keyboard has also changed, it looks like
a typewriter-style keyboard but it's not a real one, the striking is
really too soft. Some models of the Spectrum+ had a probem whereby when
you tipped the machine upside down, some of the keys would fall out! Well I love those strange keyboards they produced to
save some money, too cool.
is the bottom line: the Spectrum is amazing because it really sold millions
in Europe and around the world. Then loads of software was produced along
with many peripherals, especially the Sinclair extensions which were quite
beautiful with the same design as the ZX. The Spectrum lived long (it
is still alive for many) through its several new models : 128, +2 and
+3. The programmers have always pushed the Spectrum beyond its limits and produced
fantastic games with a computer which was in fact limited.
||+ amazing software library
+ its design
+ graphic possibilities
+ its success
+ its price
The rubber keyboard
- Poor sound
Adriaan Bloem reports to us:
Yes, there were three different models of the
ZX Spectrum. The original ZX Spectrum was referred to as the "Issue
1". They redesigned the system board (optimised it for production),
which became the "Issue 2". The last Spectrums were produced
in Taiwan, and for this production line the design was once again
updated which became "Issue 3".
Officially, the three issues of
the machine are the exact same, but because many rather undocumented
features were used in ZX Spectrum programs, small differences in timing
did show up. For example, the Spectrum put a picture on the TV screen
in "underscan" (as opposed to the "overscan" used
by DVD players) so there was a border around the screen. It was possible
to assign a colour to the border. Quickly changing the colour of the
border produced an effect of moving bands in the edge of the screen,
an effect which was used when loading programs from tape to show progress.
With some nifty timing, the border could also be given two or three
large segments of different colours. This timing was different for
the different issues though, and I remember asking users the question
"What issue is your Spectrum?" at the beginning of some
of the games I programmed.
Staffan V. adds:
If I remember correctly the first issue had
problems with the ULA (Uncommitted Logic Array, basically the input/output
chip) so that INKEY$ (gives the currently pressed key) only worked
in 50% of the cases. This was solved by adding a small PCB board (called
"dead cockroach") piggyback on the ULA. In issue 2 there
still were some problems with the ULA, but it was fixed by adding a
transistor (I think) on top of the ULA. Issue 3 had no ULA problems.
Dave Cridland, about the keyboard :
The picture you have there is a 48k - the 16k
not only had less memory (although you could upgrade), but also had
a lighter shade of grey for the infamous rubber keys.
The "Issue 1" Spectrums were, I think, all 16k, and even after upgrading them
to 48k, they weren't quite compatible with the later models, and thus the later
The Issue 1 was also shipped drastically late - they were mostly sold mail order,
so anyone who'd ordered - and therefore paid - for one was compensated by getting
a free ZX Printer with vast numbers of rolls of the "shiny toilet paper" that
this noisy thermal printer used.
Upgrade kit by Ali Mclaren:
After introduction of the ZX Spectrum + an upgrade kit was made
available for owners of the bog standard Spectrum. As I recall the kit
included the new shell (with proper hard keys) and a reset button. The
connections for this had to be soldered (!) into place on the mother
board. I have a sneaking suspicion that there was an extra memory chip
to upgrade from 24k to 48K but I'm not as sure about that.
Better display, by Mark Slabbert:
At times the colour display "drifted"
causing a slight blurring of the tv image. Beside returning the tv
you could easily open the casing and adjust either a variable capacitor
or resistor (can not remember which) to stabilise the image and sharpen
the display. Worked like a charm.
Despite the strange keys the lettering never seemed to come off even
after years of typing. Wish some of my modern remotes were of the
Grant MacDonald adds:
There were also many official and un-official external memory modules
to increase the memory to the full 48K. Many of these had heat problems
and would get quite hot! They also suffered from intermittant connections
and I remember many times waiting for my friends Speccy to load from
tape and to start running a game JUST for us to get a bit over eager
on the first key-strokes causing the ram-pack to wobble and the game
Later games used modified code
to compress the tones used on the tape drive and "turbo load"
games or use techniques called "headerless" loading (normal
Speccy files had a short header on the tape containing information
about what was to follow, how big it was, and where in RAM to locate
it) these turbo loaders could be more sensitive to the tape deck used
and manufacturers created modified tape deck where the normal screw
used to adjust the angle of the tape head was replaced by a knob to
make getting the exact angle of tape/head easier.
António Vasconcelos disagrees:
It's a error to think that typing was slow on
a rubber-keyed Spectrum. *After* you mastered the
keyboard (witch would take same time) you would be able to write BASIC
programs much faster than anyone could with a standard keyboard. I
had to type a few programs I wrote on the Spectrum into an Amstrad
PCW for printing purposes, and I know it took me much longer that
what it took me to write the original program.