Who has a sinclair scientific programmable?

[NetMage]

I had the Radio Shack EC-4001 that I used throughout high school - it was the envy of other students since I could program repetitive calculations. It is basically a Sinclair Cambridge Programmable.

[Harald]

I played a bit more with the Sinclair Scientific Programmable today and I found out what is happening. The accuracy for sin drops off very sharply beyond pi/2. Your to there it is fine, but 1.6 already yieldsa result that is completely meaningless (0.02986). Amazing how limited this calculator is.

Cheers,
Harald

[vaklaff]

(02-10-2022 01:09 PM)Harald Wrote:  I played a bit more with the Sinclair Scientific Programmable today and I found out what is happening. The accuracy for sin drops off very sharply beyond pi/2. Your to there it is fine, but 1.6 already yieldsa result that is completely meaningless (0.02986). Amazing how limited this calculator is.

See the operating instructions at https://www.wass.net/manuals/Sinclair%20...mmable.pdf. It’s by design and documented, so it’s a feature :-)

In case you can’t stand the poor machine, just send it to me, I think I can live with its limitations ;-)

[Harald]

(02-10-2022 06:41 PM)vaklaff Wrote:  See the operating instructions at https://www.wass.net/manuals/Sinclair%20...mmable.pdf. It’s by design and documented, so it’s a feature :-)

In case you can’t stand the poor machine, just send it to me, I think I can live with its limitations ;-)

Thank you! Having grown up on HP calculators it never occurred to me to read the manual for a fairly simple rpn calculator. Guess I was wrong

Thanks for the offer, I'll keep it in my collection
It won't get much use though, as that requires almost as much thought as using an algebraic calculator. And I prefere to think about the problem in hand, not the tool used to solve it...

[vaklaff]

(02-12-2022 09:22 PM)Harald Wrote:  Thanks for the offer, I'll keep it in my collection

Not that I expected anything else :-) I have the other programmable Sinclairs. Of course no real use for them - I too suspect they would be pain to use. However the Cambridge Programmable is among the most beautiful programmables I’ve seen. Big part of the magic is how small it is.

[Josef]

I recently bought two calculators, one of the first Sinclair Scientific calculators, unique because of its single-chip processor and a Sinclair Cambridge Programmable with 36 program steps. Both calculators have complete original packaging.

[Mike T.]

I actually brought one in early 1977 and I still have it (somewhere), but I replaced it with an HP31E as soon as I could afford one as it was so inaccurate, eventually I managed to save up enough to buy an HP33C which is still my favourite keystroke programmable.

[Josef]

True, Sinclair calculators did not excel in accuracy, by far, the most accurate were Texas Instruments calculators. Anyway, the white Sinclair calculators were amazingly small and beautiful.

[John Garza (3665)]

I agree. I have a few Sinclairs. We all get spoiled using HP or TI machines. Well... not 'spoiled'. Let's say accustomed to a higher standard. And stepping down is a difficult thing to do. OK for collecting, but not for actual use.

-J

[Josef]

I don't think anyone needs historical calculators anymore, but the history is wonderful and it's all about collecting. For example, the history of Sinclair is amazig, who today can invent and write firmware for a device in a few days?

The ROM storage in the calculator held only 320 instructions, just enough for basic arithmetic. How could they possibly squeeze any scientific functions into this chip?

Fortunately Clive Sinclair, head of Sinclair Radionics, had a secret weapon - programming whiz and math PhD Nigel Searle. In a few days in Texas, they came up with new algorithms and wrote the code for the world's first single-chip scientific calculator, somehow programming sine, cosine, tangent, arcsine, arccos, arctan, log, and exponentiation into the chip. The engineers at Texas Instruments were amazed.

[John Garza (3665)]

People have different desires. One may not 'need' something but desire it. And another may find the whole thing foolish. Freedom works that way.


And the cordic routines for math functions were known by those in the industry by then. Livermore BASIC in assembly had it and was freely available. Your tax dollars at work. Very smart guys nonetheless. But most were not starting from scratch.


... now if I can only convince Santa Claus I 'need' a Ferrari this year...

-J

[Josef]

Yes, I agree, lust is a terrible thing