Feeds

Google chap reverse engineers Sinclair Scientific Calculator

No Pi, only basic functions and hardly any storage, but Clive's 1974 team made it work

3 Big data security analytics techniques

A Google employee named Ken Shirriff has delved into computing history by reverse-engineering the code running Sinclair Radionics' 1974 scientific calculator.

Shirriff's story of the calculator's genesis notes that in the early 1970s a scientific calculator was an expensive and extraordinary tool for which the likes of HP could charge around $400, such was the exotic nature of its interior. Texas Instruments had come up with cheaper calculator chips that Shirriff writes “could barely do four-function math”.

The idea of turning that kit into a scientific calculator seemed improbable, to everyone except Sinclair and Nigel Searle (later the head of Sinclair Research's Computer division and apologist for ZX Microdrive delays). The former charged the latter with getting it done and the rest is history, as the Sinclair Scientific emerged at the then-astounding price of about fifty quid yet did most of what one could wish a scientific calculator to do.

Shirriff's post explains how he thinks the Sinclair team did the job. We won't spoil the algorithmic fun explained in the post, but suffice to say the Sinclair team found ways to simulate scientific calculator functions like log and trig with very clever use of the limited resources on offer in TI's TMS0800 silicon.

The post also offers a simulator and Shirriff's code, should you wish to journey back to 1974 yourself.

Sinclair Radionics went on to make several more calculator models and even digital watches. Like other Sinclair ventures, it went titsup with financial troubles after winning a reputation for kit that may not have been perfect, or even particularly reliable, but dramatically undercut rivals and therefore expanded the market.

That was certainly the case for Sinclair Research and its ZX line of microcomputers, which borrowed some of the calculator's idiosyncrasies including function keys that allowed one button to serve multiple functions. ®

SANS - Survey on application security programs

More from The Register

next story
Samsung Galaxy S5 fingerprint scanner hacked in just 4 DAYS
Sammy's newbie cooked slower than iPhone, also costs more to build
US mobile firms cave on kill switch, agree to install anti-theft code
Slow and kludgy rollout will protect corporate profits
Leaked pics show EMBIGGENED iPhone 6 screen
Fat-fingered fanbois rejoice over Chinternet snaps
Microsoft lobs pre-release Windows Phone 8.1 at devs who dare
App makers can load it before anyone else, but if they do they're stuck with it
Oh no, Joe: WinPhone users already griping over 8.1 mega-update
Hang on. Which bit of Developer Preview don't you understand?
Report: Apple seeking to raise iPhone 6 price by a HUNDRED BUCKS
'Well, that 5c experiment didn't go so well – let's try the other direction'
Feast your PUNY eyes on highest resolution phone display EVER
Too much pixel dust for your strained eyeballs to handle
Rounded corners? Pah! Amazon's '3D phone has eye-tracking tech'
Now THAT'S what we call a proper new feature
Hearthstone: Heroes of Warcraft – A jolly little war for lunchtime
Free-to-play WoW turn-based game when you have 20 minutes to kill
Zucker punched: Google gobbles Facebook-wooed Titan Aerospace
Up, up and away in my beautiful balloon flying broadband-bot
prev story

Whitepapers

Top three mobile application threats
Learn about three of the top mobile application security threats facing businesses today and recommendations on how to mitigate the risk.
Combat fraud and increase customer satisfaction
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
SANS - Survey on application security programs
In this whitepaper learn about the state of application security programs and practices of 488 surveyed respondents, and discover how mature and effective these programs are.