Feeds

Jim Westwood, home micro revolutionary

We salute Sinclair's chief geek

Secure remote control for conventional and virtual desktops

Pocket calculators and TVs

Westwood's designs, often under absurdly tight budget restraints, were never text-book, and sometimes radically risky. The notoriously high return rate on Sinclair products was disguised by the fact that many were sold in kit form. But there's no question that in pushing the envelope of how much could be got out of how little, some of the designs were essentially self-destructive.

Sinclair Radionics Cambridge calculator

The Sinclair Cambridge
Source: Vintage Calculators

By the early 1970s "Sinclair" had become a household name, and it was time for a shift from audio. Today, when you can pick one up in Poundland, it's difficult to imagine the impact of "The Executive", a sleek, black, shirt-pocket calculator that could be yours for as little as £79.95 - just a couple of weeks' wages in those days! Only four years earlier, Hewlett-Packard had introduced the first desktop electronic calculator, the HP-9100 for a price that amounted to around £20,000 in today's money.

Once again, Westwood's design was cash-squeezed, but this time there was an even bigger problem. There was a good reason why the Americans and Japanese had so far stayed away from a pocket calculator. The components were particularly power-hungry, dictating a mains connection, or at the very least large batteries.

Sinclair Executive pocket calculator

The Sinclair Executive
Source: Vintage Calculators

The display LEDs alone ate a lot of juice, but there was a standard solution to this. Instead of supplying steady power, you rapidly switched the LEDs on and off. If pulsed at around 60Hz you could save power while relying on human persistence of vision to see the light as continuous.

The trick tickled Westwood's fancy, and he found himself wondering whether it could be extended across the whole device. There was nothing in the specs for the Texas Instruments GLS 1802 calculator chip to suggest this was possible. But, after all, the circuit did include a number of capacitors, components that behave like tiny temporary batteries. Would they be able to sustain power between the pulses reliably enough to ensure there was no data loss?

Sinclair MTV-1 Micro TV

After the calculator, the telly: Sinclair's MTV-1
Source: Retro Thing

Together with Chris Curry, at this stage still a faithful Sinclair acolyte, Westwood ran the tests. The specs said the TI chip needed 350mW of power. And here it was running reliably with a pulsed current at around 20mW. Job done.

Beginner's guide to SSL certificates

Next page: Enter the computer

More from The Register

next story
Xperia Z3: Crikey, Sony – ANOTHER flagship phondleslab?
The Fourth Amendment... and it IS better
Don't wait for that big iPad, order a NEXUS 9 instead, industry little bird says
Google said to debut next big slab, Android L ahead of Apple event
Microsoft to enter the STRUGGLE of the HUMAN WRIST
It's not just a thumb war, it's total digit war
Ex-US Navy fighter pilot MIT prof: Drones beat humans - I should know
'Missy' Cummings on UAVs, smartcars and dying from boredom
Netscape Navigator - the browser that started it all - turns 20
It was 20 years ago today, Marc Andreeesen taught the band to play
A drone of one's own: Reg buyers' guide for UAV fanciers
Hardware: Check. Software: Huh? Licence: Licence...?
The Apple launch AS IT HAPPENED: Totally SERIOUS coverage, not for haters
Fandroids, Windows Phone fringe-oids – you wouldn't understand
Apple SILENCES Bose, YANKS headphones from stores
The, er, Beats go on after noise-cancelling spat
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.