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back to article Google chap reverse engineers Sinclair Scientific Calculator

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 …

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For those that, like me, have just woken up and are a bit confused: "Shirriff retells the story of the calculator's genesis by *noting*"

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Happy

I think he may also be a Google 'employee', not 'employer'.

The article author must be amongst those who just woke up!

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Unhappy

Sadly

The halcyon days of cool geekery like this are well past...

Shame.......

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Meh

Re: Sadly

Eh, but, isn't reverse engineering the damn thing cool geekery itself?

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Re: Sadly

I was hoping that whoever wrote the original implementation would be on el'reg

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Re: Sadly

Yeah, apparently these days we'd all be satisfied if we could just find a few good passable proofreaders.

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Been there, done that. In 1985.

You can still find my code in the Slackware codebase, if you know where to look.

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Anonymous Coward

Re: Been there, done that. In 1985.

Presumably whilst fighting of grizzly bears with the other hand...

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@AC: 08:31 (was: Re: Been there, done that. In 1985.)

Idiot.

I mean, really, what more can I say?

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Anonymous Coward

Re: @AC: 08:31 (was: Been there, done that. In 1985.)

Hopefully nothing.

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Anonymous Coward

Re: @AC: 08:31 (was: Been there, done that. In 1985.)

@jake - please stop being an arse. If you really did do the same in 1985, post a link to it for us all to see, or stfu.

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Re: @AC: 08:31 (was: Been there, done that. In 1985.)

Exactly. Posts along the line of "I did X way back in Y" are interesting if they contain some details; indeed, it is in hope of finding comments from those more experienced and wiser than myself that I read the Reg comments section in the first place.

However, if a RegReader makes reference to something interesting but provides no further detail, then it can only really frustrate us fellow commentards, in much the same way as reading an intriguing headline but then finding the article locked behind a paywall.

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Angel

Re: @Dave 126 (was: Been there, done that. In 1985.)

Dave, who needs details when you've lead such a rich and varied life as Jake here?

Jake Breeds & trains Cop dogs & horses and is Qualified to Judge Best In Show at American Kennel Club shows

Has friends in South Korea

Was a friend and neighbour of Steve Jobs and has his signature carved in his picnic table

Worked on spacecraft software/firmware

Mentored the founders of Google

Helped work out how to transfer the existing NCP ARPANet to the existing TCP/IP network

Has been Usenet & Mailinglist moderator for 30 years

Is a qualified pilot

Does track day driving

Has done arctic survival training and has eaten Lemming

Knows FORTRAN and COBOL

He ego-surfed the OSX source & found shit he re-wrote from AT&T source nearly 25 years ago

Has been making money from his knowledge of the PDP11 family since 1979

Has an extensive gun collection, was shooting gophers before he was in kindergarten and can fire his Great Grandfather's Kentucky over twice a minute

Watched a guy get killed by a claw hammer thrown from 35 feet up in Humboldt County

Watched a friend once won a bar bet by sticking 7 of 10 Craftsman brand screwdrivers into a straw archery butt at 15 yards in under 15 seconds

His kid/daughter (varies) is the Senior Member of the Technical Staff in a Fortune 150/250 (varies) corporation. She owns 6 horses, and is quite competitive in hunter/jumper, eventing & dressage

Can and has lived off the land, Makes road kill sausages several times a year, Owns a couple acres of Merlot grapes here that have Eucalyptus genes and grows Gravensteins (15 acres, originally planted by his great-grandfather)

Got kicked out of "Sunday School" when I was roughly 8 years old

Owns an outdoor 1875 stone bread oven

Owns a drilled-into-the-rock iron-ring tidal mooring on the Noyo River in Northern California. His Great Grandfather claimed it in 1872

Runs several "at risk yoof" camps every year.

Is a locksmith. Learned to pick locks before he was a teenager. Can open most house-hold doors with no more than a safety-pin & a bobby-pin.

Once could have shot the an intruder he had at chez jake, but when he got down to the kitchen, where he was, instead calmly put down his Kimber & picked up the phone & called the non-emergency police line. When they arrived, called off the dogs & he was transported to the hospital to stop the bleeding.

Can still read text/code on cards and tape, and sometimes "think" in octal and hex. A partially sighted friend can read punched paper with her fingers, similar to braille.

Accepted 7 contracts in the last 18 months pulling corporations out of the clouds. It's actually quite lucrative (apparently)

Has never has used google/youtube. Ever.

I for one think we have a great deal to learn from this man.

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@Jared Hunt

As long as that list is... it's not quite complete

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Re: @Jared Hunt it's not quite complete

I'm sure it isn't. I got bored after reading a couple of hundred posts. I'd be keen to see the complete version ;)

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Happy

Re: @Dave 126 (was: Been there, done that. In 1985.)

Not to mention HR conslutant.

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Re: Been there, done that. In 1985.

You certainly have done a lot of ego stroking, jake, but not a lot of proof-providing.

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Anonymous Coward

Re: @Jared Hunt it's not quite complete

There is no complete version. The list is infinite, there is literally nothing he hasn't done.

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Anonymous Coward

Re: @Jared Hunt it's not quite complete

I bet he even trolls himself via these Anonymous Coward posting, just so he can add "internet troll" to the list.

Maybe I am him

maybe I grok trolling

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Pint

Re: Been there, done that. In 1985.

Writing code in 1985?

Noobie.

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Re: Been there, done that. In 1985.

jake applied to work for my (entirely fictional) Silicon Valley startup. I retained a copy of his CV:

I am a dynamic figure, often seen scaling walls and crushing ice. I have been known to remodel train stations on my lunch breaks, making them more efficient in the area of heat retention. I translate ethnic slurs for Kenyan refugees. I write award winning operas and manage time efficiently. Occasionally, I tread water for 3 days in a row.

I woo women with my sensuous and godlike trombone playing, I can pilot bicycles up severe inclines with unflagging speed and I cook 30 minute brownies in 20 minutes. I am an expert in stucco, a veteran in love and an outlaw in Peru. Using only a hoe and a large glass of water, I once single handedly defended a small village in the Amazon Basin from a horde of ferocious army ants. I play bluegrass cello, I had trials with Manchester United, I am the subject of numerous documentaries.

When I'm bored, I build large suspension bridges in my garden, I enjoy urban hand gliding. On Wednesdays, after school, I repair electrical appliances free of charge.

I have been awarded both the Fields Medal and the Nobel Prize for Literature. I am an abstract artist, a concrete analyst and a ruthless bookie. I have provided confidential intelligence advice to the last four Presidents.

Critics worldwide swoon over my original line of corduroy evening wear. I don't perspire. Last Summer I toured Eastern Europe with a travelling centrifugal force demonstration. I run the 100m in 9.65 seconds. My deft floral arrangements have earned me fame in international botany circles.

Children trust me.

I can hurl tennis rackets at small moving objects with deadly accuracy. I once read Paradise Lost, Moby Dick and David Copperfield in one day and still had time to refurbish an entire dining room that evening. I know the exact location of every food item in the supermarket. I have performed several covert operations for the CIA. I sleep once a week; when I do sleep, I sleep in a chair. While on vacation in Canada, I successfully negotiated with a group of terrorists who had seized a small bakery. The laws of physics do not apply to me.

I balance, I weave, I dodge, I frolic and my bills are all paid. On weekends, to let off steam, I participate in full contact origami. Years ago I discovered the meaning of life but forgot to write it down.

I have made extraordinary four course meals using only some vegetables and a Breville Toaster. I breed prize winning clams.

I have won bullfights in Madrid, cliff-diving competitions in Sri Lanka and chess competitions at the Kremlin. I have played Hamlet, I have performed open-heart surgery and I have spoken with Elvis.

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Coffee/keyboard

Re: @Fictional CV

Seems legit.

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Joke

Re: @Jared Hunt it's not quite complete

Jake is Chuck Norris. It's the only logical conclusion.

That said, the CV posted earlier is clearly not his. His CV would read simply:

"I am Chuck Norris."

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Hey!

I also know (knew) FORTRAN, nothing wrong about that. But COBOL, is that where the 13th colony got lost or something?

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Trollface

Re: Been there, done that. In 1985.

1985? Slacker. I did it in 1965. I think the source is still on GitHub somewhere. But you'll have to email the admin and ask for the punched tape to be threaded in before you try to download it.

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Re: @Dave 126 (was: Been there, done that. In 1985.)

Does come across rather Walter Mitty.

Pinch of salt.

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You lot really have issues.

Some of us have actually been there & done that.

Carry on, all.

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Anonymous Coward

Re: @Dave 126 (was: Been there, done that. In 1985.)

You forgot his MBA :)

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Anonymous Coward

Re: Been there, done that. In 1985.- (entirely fictional)

Seems pretty par for the course for the CV of anyone under 25, these days.

Though to be fair there was the middle aged guy who applied to us once for a sales job, and I had to phone him up and ask him "with this CV, why aren't you running Unilever?"

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Re: Been there, done that. In 1985.

bluegrass cello! Excellent!

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Yet more Jake quotes.

Has several degrees including the MBA ("I got mine in about 18 months").

Attended Stanford University and was admonish by the Deen for correcting the Professor in class.

Was a TA for the Google founders.

Worked on transfering NCP ARPANet to TCP/IP.

Was a personal associate with Steve Jobs.

Steve Jobs carved his name into Jakes picnic table.

Is a trained pilot, "I got my ticket off of Sutton Bank in the early 1970s, and am still a member of The Yorkshire Gliding Club".

Been contributing to the Linux kernel for about 21 years.

Worked at DEC when Ken Olsen fired someone for 'walking' the washing machine sized disk drive across the floor.

Sat on "various panels of industry professionals MS brought in for input (large, medium, small and home) in the couple decades prior to 2000".

Posesses multiple server "boxes" in different locations, Palo Alto, New York, at Sun, Palo Alto, Edinburgh, Auckland, Duluth and Nyack.

WTC: "Had gear on top of both towers, and in the basements of both (and at Sun, on floors 25 and 26 WTC2)".

WRC, helped with the rescue: "A couple dogs I had trained were involved in the search and rescue effort".

WRTC, rebuilt the infrastructure: "a couple dozen of us were awake for about a week, cat-napping occasionally, rebuilding the logical infrastructure manually".

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Trollface

Re: You lot really have issues.

"Some of us have actually been there & done that."

Could you name someone who has?

Thanks.

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Anonymous Coward

what?

I'm still saving up for my wrist radio!

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Boffin

The perfect calculator!

You think not? How many of the kids at school ever borrowed it a *second* time?

My first calculator... and the RPN led me eventually to Forth and the three or four HP calculators I still use. *Loved* that odd red/purple colour in the LEDs.

Though the maddest thing I ever did to it was to dismember the thing when the keyboard finally died, and use it as a co-processor for (ahem) a Sinclair MK14... with transistors being driven to simulate keypresses and a small amount of hardware to decode the multiplexed LED output. Still got the MK14 but the Scientific is long in silicon heaven.

It would probably have been quicker to have written the routines directly. My word it was sloooooooooooooooooooow!

Kudos to Mr Shirriff.

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Re: The perfect calculator!

How many of the kids at school ever borrowed it a *second* time?

I was going to say the same; the most frequent refrain after "lend us your calculator" was "where's the equals button?"

I still have mine. I think it's a lovely design but, beyond having to grapple with RPN, it had two problems; poor battery contacts and the sliding power button had prongs sliding over PCB tracking which were not good at withstanding wear.

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Re: The perfect calculator!

My Mum bought me the kit, it still works today although I have had to resolder both the battery contacts and repair the sliding switch. The transfer with Pi/e/etc. on it has worn off, but the rest of the case is in good shape.

A little later one of my friends got the upgraded Cambridge Scientific (faster, and not RPN) and his came in a hard plastic case instead of a purple cloth bag. I wrote to Sinclair asking if it was possible to buy a case, and they sent me one for free :) Nice service.

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Anonymous Coward

Re: The perfect calculator!

How many of the kids at school ever borrowed it a *second* time?

I had loads of fun in school with my dad's hand-me-down HP scientific calcs.

One of the best things was to put it in octal mode before someone borrowed it:

"4 * 25"

"124"

*anywhere from two minutes to one day later*

"Hey, what's up with your stupid calculator?!"

Hex was pretty cool for that, too:

[guy] "Uh, I think this thing is broken - it says that nine times seven is 3F?!"

[me, switching mode surreptitiously as I take the calculator from him] "Uh, no, it says 63. Are you feeling all right?"

[guy] ****?

I amused quite a few kids for a long time by writing a program for the HP 12C which was essentially a random number generator, but by dint of technobabble and force of will I convinced people that if they typed yes or no questions into the calculator in a certain way (using numeric substitution for letters) that it would answer correctly. People took it surprisingly seriously; had I been cannier, I could probably have printed money... Oh well.

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Boffin

Re: The perfect calculator!

I was going to say the same; the most frequent refrain after "lend us your calculator" was "where's the equals button?"

One particularly obnoxious and ignorant twit, whose sense of entitlement apparently extended to me supplying him with a calculator, took about five minutes of key-pounding (this was an HP29; it could take the abuse) before latching on to the lack of the equals key. He then demanded "a normal calculator".

"Here, have my slide rule".

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Re: The perfect calculator!

"Here, have my slide rule"

Which, in effect, the calculator was. 3dp accuracy, RPN, everything in exponent form. About as accurate (probably as fast) as a 24" slide rule, but a little more pocketable.

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This post has been deleted by its author

Suffice it

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Squeezetastic

The Sinclair Scientific was a true engineering triumph: squeezing the UI and operation of a scientific calculator into just 320 x 11-bit program steps written in just 3 days from a hotel in Texas (how on earth did they test it?).

But it explains why Sinclair thought floating point would be trivial for his series of computers: if you can fit it into <0.4Kb* then it should have been no problem fitting into his second computer (as he promised) given its expansive 4Kb Super-ROM... but users had to wait for the 8K ROM ZX81 before that kind of luxury became available (the MK14 was his first computer).

Ken's post is brilliant, all the more amazing for the fact that we now know more about the Sinclair Scientific then we ever did, 39 years after it came out; and gain a better insight for why Sir Clive Sinclair was seen as the (eccentric) 1970s genius instead of the 80s techie front-man. Digital archeology at its best!

-cheers from Julz

[* 320x11-bits is about 440 bytes]

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Ahhh, RPN and the shunting yard....

...brings back bad memories.

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Meh

Luxury!

Four function calculator? When I were a lad we had to do trig on our fingers!

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Re: Luxury!

Fingers! The luxury! When I were a lad our fingers were worn down to stumps from workin' in mine 25 hours a day! We had to do integration using naught but a bit of slate and a stick and if we got it wrong our da' would beat us to death, and we would still be up in mornin' down pit minin' hot lava for lava mills!

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Anonymous Coward

Re: Luxury!

Stick and a full piece of slate he says........Eeeeeeeeh, hark at it!

I used to dream of a stick and a bit of slate. When I was a lad, all we had was nowt but a bit of mud to grub about in and we were glad of it letmetellyou.

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Re: Luxury!

Slate and Stick? By 'eck.. that sounds like real luxury to me! When I were a lad we'd worn all our limbs to stumps down't t'pit and we had to call out the numbers to a crippled lad in't village who'd add it up for us. Tha knows..

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Coat

Re: Luxury!

By 'eck you lot had it like the Queen. We longed for limbs and our parents all died long before we were born...

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Anonymous Coward

Re: Luxury!

Mud! Stumps! Village Idiot...

Eeeh the luxury you lot had, we used to dream of finger stumps, we'd eaten our fingers long before then to stave off the cold.

Mud was something only the posh people had, we had to make do with rocks, no water mind you, couldn't afford it, we'd bash them together to try and get some protein out of them, made a loverly gruel and kept you regular,

And I was the Village Idiot....

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