1980 saw a genuine breakthrough - the Sinclair
ZX80, the world's first complete personal computer for under
£100. Not surprisingly, over 50,000 were sold.
In March 1981, the Sinclair lead increased
dramatically. For just £69.95 the Sinclair ZX81 offers
even more advanced facilities at an even lower price. Initially,
even we were surprised by the demand - over 50,000 in the
first 3 months!
Today, the Sinclair ZX81 is the heart of
a computer system. You can add 16 times more memory with the
ZX RAM pack. The ZX Printer offers an unbeatable combination
of performance and price. And the ZX Software library is growing
Lower price: higher capability
With the ZX81, it's still very simple to
teach yourself computing, but the ZX81 packs even greater
working capability than the ZX80.
It uses the same micro-processor, but incorporates
a new, more powerful 8K BASIC ROM - the 'trained intelligence'
of the computer. This chip works in decimals, handles logs
and trig, allows you to plot graphs, and builds up animated
And the ZX81 incorporates other operation
refinements - the facility to load and save named programs
on cassette, for example, and to drive the new ZX Printer.
Higher specification, lower price
- how's it done?
Quite simply, by design. The ZX80 reduced
the chips in a working computer from 40 or so, to 21. The
ZX81 reduces the 21 to 4!
The secret lies in a totally new master
chip. Designed by Sinclair and custom-built in Britain, this
unique chip replaces 18 chips from the ZX80!
New, improved specification
- new faster version of the famous Z80 chip, widely recognised
as the best ever made.
key word entry: the ZX81 eliminates a great deal of tiresome
typing. Key words (RUN, LIST, PRINT, etc.) have their own
and report codes identify programming errors immediately.
Full range of mathematical
and scientific functions accurate to eight decimal places.
animated display facilities.
string and numerical arrays.
Up to 26 FOR/NEXT
- useful for games as well as serious applications.
Cassette LOAD and
SAVE with named programs.
1K-byte RAM expandable
to 16K bytes with Sinclair RAM pack.
Able to drive the
new Sinclair printer.
Advanced 4-chip design:
microprocessor, ROM, RAM, plus master chip - unique, custom-built
chip replacing 18 ZX80 chips.
Kit or built -
it's up to you!
You'll be surprised
how easy the ZX81 kit is to build: just four chips to assemble
(plus, of course the other discrete components) - a few hours'
work with a fine-tipped soldering iron. And you may already
have a suitable mains adaptor - 600 mA at 9 V DC nominal unregulated
(supplied with built version).
Kit and built versions come complete with
all leads to connect to your TV (colour or black and white)
and cassette recorder.
16K-byte RAM pack for massive add-on
Designed as a complete module to fit your
Sinclair ZX80 or ZX81, the RAM pack simply plugs into the
existing expansion port at the rear of the computer to multiply
your data/program storage by 16!
Use it for long and complex programs or
as a personal database. Yet it costs as little as half the
price of competitive additional memory. With the RAM pack,
you can also run some of the more sophisticated ZX Software
- the Business & Household management systems for example.
- the ZX Printer for only £49.95
Designed exclusively for use with the ZX81
(and ZX80 with 8K BASIC ROM), the printer offers full alphanumerics
and highly sophisticated graphics.
A special feature is COPY, which prints
out exactly what is on the whole TV screen without the need
for further intructions. At last you can have a hard copy
of your program listings-particularly useful when writing
or editing programs.
And of course you can print out your results
for permanent records or sending to a friend.
Printing speed is 50 characters per second,
with 32 characters per line and 9 lines per vertical inch.
The ZX Printer connects to the rear of your
computer - using a stackable connector so you can plug in
a RAM pack as well. A roll of paper (65 ft long x 4 in wide)
is supplied, along with full instructions.
How to order your ZX81
BY PHONE - Access, Barclaycard or Trustcard
holders can call 01-200 0200 for personal attention 24 hours
a day, every day.
BY FREEPOST - use the no-stamp needed coupon
below. You can pay by cheque, postal order, Access, Barclaycard
EITHER WAY - please allow up to 28 days
for delivery. And there's a 14-day money-back option. We want
you to be satisfied beyond doubt and we have no doubt that
you will be.
To: Sinclair Research, FREEPOST, Camberley,
Surrey, GU15 3BR
ZX81 Personal Computer kit(s). Price includes ZX81 BASIC
manual, excludes mains adaptor.
Sinclair ZX81 Personal Computer(s). Price includes ZX81
BASIC manual and mains adaptor.
Adaptor(s) (600 mA at 9 V DC nominal unregulated).
BASIC ROM to fit ZX80.