Feeds

Jim Westwood, home micro revolutionary

We salute Sinclair's chief geek

Gartner critical capabilities for enterprise endpoint backup

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.

Boost IT visibility and business value

Next page: Enter the computer

More from The Register

next story
Apple takes blade to 13-inch MacBook Pro with Retina display
Shaves price, not screen on mid-2014 model
iPhone 6 flip tip slips in Aussie's clip: Apple's 'reversible USB' leaks
New plug not compatible with official Type-C, according to fresh rumors
FEAST YOUR EYES: Samsung's Galaxy Alpha has an 'entirely new appearance'
Wow, it looks like nothing else on the market, for sure
YES YES YES! Apple patents mousy, pressure-sensing iVibrator
Fanbois prepare to experience the great Cupertin-O
Steve Jobs had BETTER BALLS than Atari, says Apple mouse designer
Xerox? Pff, not even in the same league as His Jobsiness
TV transport tech, part 1: From server to sofa at the touch of a button
You won't believe how much goes into today's telly tech
Apple analyst: fruity firm set to shift 75 million iPhones
We'll have some of whatever he's having please
Things are looking up in Flappy Bird sequel
'Swing Copters' offers the same gameplay but in a different direction
prev story

Whitepapers

5 things you didn’t know about cloud backup
IT departments are embracing cloud backup, but there’s a lot you need to know before choosing a service provider. Learn all the critical things you need to know.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.
Rethinking backup and recovery in the modern data center
Combining intelligence, operational analytics, and automation to enable efficient, data-driven IT organizations using the HP ABR approach.
Next gen security for virtualised datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.