Who has a sinclair scientific programmable?

[Harald]

I bought one a year ago and finaly picked it up at a friends house in the UK. I gave it a thorough clean today and installed a battery. Basic operations seem to work fine, although the acuracy leaves a bit to be desired.

30 SIN, after blanking the display for ages produces 0.84265 ?!?

Also, pressing keys often produces (this is reproducable) brightly flashing digits. Is that normal?

Maybe someone who has such a calculator can confirm this behaviour.

Cheers,
Harald

[Steve Simpkin]

More information about the remarkable development of this rather unremarkable scientific calculator:
http://files.righto.com/calculator/sincl...lator.html

Operating Manual:
http://phils.bitboxes.co.uk/scan_and_ocr...cientific/
Or
http://www.datamath.net/Manuals_Others/S...fic_GB.pdf

More information:
https://www.keesvandersanden.nl/calculat...ntific.php

[Harald]

(07-05-2018 08:10 AM)Steve Simpkin Wrote:  More information about the remarkable development of this rather unremarkable scientific calculator:
http://files.righto.com/calculator/sincl...lator.html

Operating Manual:
http://phils.bitboxes.co.uk/scan_and_ocr...cientific/

The operating manual helped me figure out that the acuracy isn't quite as bad as I had thought. It operates in radians....

[Steve Simpkin]

Given the extreme limitations of the hardware and program code size, it was an amazing achievement. Still, using it reminds me of using a slide rule. It definitely requires more work on your part compared to other scientific calculators of the time.

[Thomas Okken]

(07-05-2018 08:10 AM)Steve Simpkin Wrote:  More information about the remarkable development of this rather unremarkable scientific calculator:
http://files.righto.com/calculator/sincl...lator.html

Operating Manual:
http://phils.bitboxes.co.uk/scan_and_ocr...cientific/
Or
http://www.datamath.net/Manuals_Others/S...fic_GB.pdf

More information:
https://www.keesvandersanden.nl/calculat...ntific.php

These all refer to the Sinclair Scientific, but Harald was asking about the Sinclair Scientific Programmable. There's information about that calculator, including a scan of the manual, here: https://www.keesvandersanden.nl/calculat...lairsp.php

[EdS2]

Under £30 in October '75 - see two-page advert
https://books.google.co.uk/books?id=w1bp...C&pg=PA264
Price is inclusive of tax and shipping, and there's a 10-day money-back guarantee. (On the downside, Sinclair were often very slow to ship and often launched product and took payment before they had volume production.)

By contrast, the HP-65 cost £490 in July of the previous year. No contest at all in quality, accuracy, features, but Sinclair wins on price by an order of magnitude.
https://books.google.co.uk/books?id=HoZd...QC&pg=PA16

[Steve Simpkin]

(07-06-2018 08:31 AM)EdS2 Wrote:  Under £30 in October '75 - see two-page advert
https://books.google.co.uk/books?id=w1bp...C&pg=PA264
Price is inclusive of tax and shipping, and there's a 10-day money-back guarantee. (On the downside, Sinclair were often very slow to ship and often launched product and took payment before they had volume production.)

By contrast, the HP-65 cost £490 in July of the previous year. No contest at all in quality, accuracy, features, but Sinclair wins on price by an order of magnitude.
https://books.google.co.uk/books?id=HoZd...QC&pg=PA16

Well to be fair, the Sinclair Scientific Programmable should really be compared to the HP-25 which sold for £119 in Sept 1975. Even so, the HP-25 was 4 times the price of the Sinclair (and well worth the premium if you could afford it).

The only Sinclair product I ever owned was the Sinclair Wrist Calculator around late 1977. I assembled it from a kit and it did work but there were mechanical problems with the case design and battery life for the six mercury cells was very poor. I had wanted to get the Sinclair Watch when it came out but I ended up getting a very nice LCD watch shortly afterwards. Given all the polyester I wore back then and the fact that we had a cat, the Sinclair Watch wouldn't have lasted a week anyways

[EdS2]

Ah - I hadn't realised the HP-25 was quite so early or so affordable!
https://books.google.co.uk/books?id=nEdj...C&pg=PA715
   

[Thomas Klemm]

Quote:So much pre-programmed power
So much memory

Wow, I didn't know that Hewlett-Packard also invented the Doge meme.
And that 38 years before it was cool.
Such hipster.

[EdS2]

Also notable: HP saying they already have a million users of their RPN calculators.

[Chasfield]

I have just dug out my SSP and put a PP3 battery in it. So returning to the original question regarding flashing digits:

Some arithmetic operations (multiply and divide) cause a digit of the result mantissa to flash brightly for a split second as it settles. Not so with addition and subtraction. This flashing only occurs if the last operand entered had more than one digit. Repeated pressing of any arithmetic operator key against an established result causes a display digit to briefly flash.

Some slide rule functions produce similar behaviour (1/x and x^2) but square root (x) does not always do so.

No bright digit shows for Sin(x). With Cos(x), a bright zero shows at the exponent sign position while the calculator is thinking. With ArcTan(x), a bright zero shows at the leftmost display position while the calculator is thinking.

Without doubt there was no spare RAM for putting in extra code to suppress these display glitches.

I can confirm your result for 30 Sin input, and the thinking time is 20 seconds!

The serial number of my unit, printed in red on the inside of the battery cover, is 015335.

I hope this is helpful.

[Thomas Okken]

(07-06-2018 05:11 PM)Steve Simpkin Wrote:  Well to be fair, the Sinclair Scientific Programmable should really be compared to the HP-25 which sold for £119 in Sept 1975. Even so, the HP-25 was 4 times the price of the Sinclair (and well worth the premium if you could afford it).

My first calculator was a Sinclair Scientific (non-Programmable). It was very limited and not very accurate, but nonetheless it was better than a slide rule. Also, the manual, short as it was, showed several examples of practical engineering calculations, which gave me a first glimpse of what those mysterious trigs and logs could do (I was in 5th or 6th grade at the time!), and sparked an interest in mathematics that has stayed with me ever since.

About two years later, my dad bought me an HP-25, and oh yes, that was unbelievably cool and powerful by comparison.

[Harald]

(07-09-2018 12:56 PM)Chasfield Wrote:  I have just dug out my SSP and put a PP3 battery in it. So returning to the original question regarding flashing digits:

Some arithmetic operations (multiply and divide) cause a digit of the result mantissa to flash brightly for a split second as it settles. Not so with addition and subtraction. This flashing only occurs if the last operand entered had more than one digit. Repeated pressing of any arithmetic operator key against an established result causes a display digit to briefly flash.

Some slide rule functions produce similar behaviour (1/x and x^2) but square root (x) does not always do so.

No bright digit shows for Sin(x). With Cos(x), a bright zero shows at the exponent sign position while the calculator is thinking. With ArcTan(x), a bright zero shows at the leftmost display position while the calculator is thinking.

Without doubt there was no spare RAM for putting in extra code to suppress these display glitches.

I can confirm your result for 30 Sin input, and the thinking time is 20 seconds!

The serial number of my unit, printed in red on the inside of the battery cover, is 015335.

I hope this is helpful.

Thank you for confirming the behaviour! I thought it was due to the limited resources, but then wondered if maybe it could also be a hardware issue that was causing this.
Mine is a little worn and did not have any serial number.

I tried to get through the day using it instead of my trusty 15c. I did manage but it was a bit of a struggle :-)
Worst of all is the two level stack, wich even gets corrupted by some functions.

Still, it is a nice piece of history and I am glad I got one.

Cheers,
Harald

[Steve Simpkin]

(07-09-2018 06:46 PM)Thomas Okken Wrote:  

(07-06-2018 05:11 PM)Steve Simpkin Wrote:  Well to be fair, the Sinclair Scientific Programmable should really be compared to the HP-25 which sold for £119 in Sept 1975. Even so, the HP-25 was 4 times the price of the Sinclair (and well worth the premium if you could afford it).

My first calculator was a Sinclair Scientific (non-Programmable). It was very limited and not very accurate, but nonetheless it was better than a slide rule. Also, the manual, short as it was, showed several examples of practical engineering calculations, which gave me a first glimpse of what those mysterious trigs and logs could do (I was in 5th or 6th grade at the time!), and sparked an interest in mathematics that has stayed with me ever since.

About two years later, my dad bought me an HP-25, and oh yes, that was unbelievably cool and powerful by comparison.

Very cool! I still have my HP-25 which I bought in June 1977 for $116 USD. I used it through high school, four years of college and the first two years of my first job. It still works great!

My first RPN calculator was a Novus Mathematician (it was free). It was a bit more functional and accurate than the Sinclair Scientific but it had no provision for entering or displaying scientific notation, which was a big drawback for engineering use. Still it introduced me to RPN so it wasn't all bad The HP-25 Owner's Handbook is what really got me hooked on RPN. I still have fun reading it.

[Dave Britten]

I just received one of these today, and spent a little time cleaning up the keyboard contacts so that it actually works quite well now. It's definitely a pretty nasty machine, though - 5-digit precision, the only trig functions are sin, cos, and arctan, there's no natural log or e^x, and so on. But what I find impressive about it is the lovingly produced program library that came with it. It has hundreds of formulas and accompanying programs on heavy card stock, all written to work within the meager 24-step program memory and almost complete lack of flow control. It makes me wonder whether they couldn't have cut back on the documentation expenses and used that to produce a calculator that isn't so thoroughly embarrassed by the HP 25.

[JimP]

(07-05-2018 08:00 AM)Harald Wrote:  I bought one a year ago and finaly picked it up at a friends house in the UK. I gave it a thorough clean today and installed a battery. Basic operations seem to work fine, although the acuracy leaves a bit to be desired.

30 SIN, after blanking the display for ages produces 0.84265 ?!?

Also, pressing keys often produces (this is reproducable) brightly flashing digits. Is that normal?

Maybe someone who has such a calculator can confirm this behaviour.

Cheers,
Harald

I have one of these clunkers that I bought from TOS and had shipped from the UK to Australia over 10 years ago. It was in quite good condition, really, complete with its extensive program library, but the keyboard and digit behavior was dodgy. Never did get around to repairing it (no skills in that regard) but it brought back memories from high school in 1973 when I received one of the original Cambridges, as a gift from my dad, and then three years later invested in an Oxford 300 scientific to help with the final two years' math. Went to live in the US for the next 30 years or so, where there were no Sinclairs at all, but the Oxford kept me going through the first few months of college. Wish I'd kept it, but maybe it burned out and wound up in the bin.

[Harald]

(02-03-2022 07:04 PM)Dave Britten Wrote:  I just received one of these today, and spent a little time cleaning up the keyboard contacts so that it actually works quite well now.

So what does it display after pressing 30 sin?

[toml_12953]

(02-03-2022 07:04 PM)Dave Britten Wrote:  It makes me wonder whether they couldn't have cut back on the documentation expenses and used that to produce a calculator that isn't so thoroughly embarrassed by the HP 25.

For 1/2 the price of the 25, it's not a bad calculator!

[toml_12953]

(07-05-2018 08:00 AM)Harald Wrote:  I bought one a year ago and finaly picked it up at a friends house in the UK. I gave it a thorough clean today and installed a battery. Basic operations seem to work fine, although the acuracy leaves a bit to be desired.

30 SIN, after blanking the display for ages produces 0.84265 ?!?

Also, pressing keys often produces (this is reproducable) brightly flashing digits. Is that normal?

Maybe someone who has such a calculator can confirm this behaviour.

Cheers,
Harald

Was the Sinclair Cambridge Programmable any better?

[Dave Britten]

(02-05-2022 01:29 PM)toml_12953 Wrote:  

(07-05-2018 08:00 AM)Harald Wrote:  I bought one a year ago and finaly picked it up at a friends house in the UK. I gave it a thorough clean today and installed a battery. Basic operations seem to work fine, although the acuracy leaves a bit to be desired.

30 SIN, after blanking the display for ages produces 0.84265 ?!?

Also, pressing keys often produces (this is reproducable) brightly flashing digits. Is that normal?

Maybe someone who has such a calculator can confirm this behaviour.

Cheers,
Harald

Was the Sinclair Cambridge Programmable any better?

In terms of accuracy, not a lot, but as far as functionality, it's quite a bit better. It's still certainly no HP 25 though!