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**Gene** · 08-18-2017, 03:13 PM

Detective work time... what was the first pocket calculator produced that would commute gamma? Not a program keyed in, but as a built in function?

I have found one from sometime in 1975 (!)...and yes the (!) is a pun on factorial/gamma.

Anyone, I'll post what that model is shortly, but what can you find? HP's first? Some other model near or earlier than 1975?

Enjoy the search.

Didier Lachieze · (This post was last modified: 08-18-2017 04:04 PM by Didier Lachieze.)

1975 (!)

I thought the first was the Commodore SR4190R, but it's from 1976, not 1975....

Edit: well, after some detective work I've found the KingsPoint SC-60 (same as the Realtone SC-60 or MBO Alpha II) and the KingsPoint SC-6010 which are from 1975 and provide a gamma function on their keyboard.

**Gene** · 08-18-2017, 04:16 PM

You found it!

Here's a great website with TONS of info on TONS of calculators (in french, but google chrome translates it just fine):

The Ray of Calculators

I love that site. We should try to get the person who runs it to come to the museum!

and page on the Kingspoint SC-60 from 1975 with gamma!

SC60

**Gene** · 08-18-2017, 04:31 PM

and, looking at the good picture of the SC60, I notice another oddity.

Between the 0 key and the = key, Kingspoint decided to place the X^Y key.

Usually, the +/- key is near the digit keys, but they decided to place the powers key in a very prominent position and put the +/- key up in the smaller keys (on the fourth row from the top, fourth key from the left).

That's a very odd choice IMO.

everettr · 08-18-2017, 06:37 PM

I learned about the gamma function from my first love, the Melcor SC655. This beauty (those keys, those colors, those 12 memories!) was released in 1975. You can see the gamma function right next to the white function key.
[Image: MelcorSC655_1.jpg]

Regards,

Everett

Thomas Okken · (This post was last modified: 08-18-2017 08:42 PM by Thomas Okken.)

(08-18-2017 03:13 PM)Gene Wrote: Detective work time... what was the first pocket calculator produced that would commute gamma? Not a program keyed in, but as a built in function?

Anyone, I'll post what that model is shortly, but what can you find? HP's first? Some other model near or earlier than 1975?

I seem to remember, and the Museum agrees, that the first HP calculator with built-in gamma was the HP-34C, in 1979.

Sylvain Cote · 08-19-2017, 01:16 AM

(08-18-2017 04:16 PM)Gene Wrote: Here's a great website with TONS of info on TONS of calculators (in french, but google chrome translates it just fine): The Ray of Calculators
I love that site. We should try to get the person who runs it to come to the museum!

Thank you Gene, I was not aware of this site, very interesting and no translation needed for me Wink

Sylvain

**Gene** · 08-19-2017, 06:28 PM

Great!

If you could find a way to reach out to the website operator, he / she would make a wonderful addition to the community.

The site is VERY well done.

Didier Lachieze · 08-19-2017, 07:14 PM

I concur, this site is a real gem. I have contacted the owner, he may show up here. I know him from the pocket section of the French MySilicium forum.

**Gene** · 08-19-2017, 08:13 PM

I found the site a couple of years ago and then it disappeared rather quickly much to my dismay!

Found it just the other day - I think the host is different. Glad it is back.

Dominique*0399 · 08-20-2017, 04:42 PM

Hello everyone. My name is Dominique, author of the French site "le rayon des calculatrices" and very happy you like it. I have known the HP museum for a long time and would be very proud to contribute if you can excuse my poor imperfect English. But I want to improve ! Thank you for welcoming me. See you soon.
Dominique

**Gene** · 08-20-2017, 06:50 PM

Hello Dominique and welcome!

I am glad you have joined us here. I have loved your website and overviews of calculators, HP or otherwise, for some time.

Couple of questions:

1) Your calculators tend to show the same number in the display. Where does that number come from ?

2) If you get a chance, some of us would **love** links to high quality pictures of your machines.

Glad to have you here! Your English is fine. Try to imagine my FRENCH. :-)

pier4r · 08-20-2017, 07:12 PM

(08-20-2017 04:42 PM)Dominique*0399 Wrote: Hello everyone. My name is Dominique, author of the French site "le rayon des calculatrices" and very happy you like it. I have known the HP museum for a long time and would be very proud to contribute if you can excuse my poor imperfect English. But I want to improve ! Thank you for welcoming me. See you soon.
Dominique

Really nice site you have!

Dominique*0399 · 08-20-2017, 07:45 PM

Thank you very much Gene and Pier4r for these encouragements

(08-20-2017 06:50 PM)Gene Wrote: 1) Your calculators tend to show the same number in the display. Where does that number come from ?

2) If you get a chance, some of us would **love** links to high quality pictures of your machines.

Mantiss shows 42 square root. Why 42 ? Many pictures of calulators show "1234567890". Personally I find that display sad and unpleasantly visually. I prefer SQR (42), which I find much more pleasant for the eyes. And for a mysterious reason I love the number 87. There is no really "mathematical" reasons. This answer is probably a little disappointing I fear ...

For links to quality images, I will gladly give you them. However, I only have access to each image individually, unfortunately I do not have access to the host's pictures library. If you designate pictures to me, I will be of course very happy to give you all desired links.

Dominique

Dieter · (This post was last modified: 08-23-2017 07:50 PM by Dieter.)

(08-18-2017 04:16 PM)Gene Wrote: ...and page on the Kingspoint SC-60 from 1975 with gamma!

SC60

Quote from that site: "Parmi les fonctions traitées, on trouve notamment la Gamma, la distribution normale 1-Q(X), ..."

I wonder how these functions were calculated. Did the SC-60 really return full-precision results for Gamma resp. the Normal CDF? I remember a Commodore manual from that era (SR-61) which stated error bounds for the normal distribution that match the well-known Hastings approximations, i.e. the inverse was only good for three decimals. Unlike the later HP-32E. ;-)

So how was it done on the SC-60 ?

Dieter

Dominique*0399 · (This post was last modified: 08-24-2017 08:25 PM by Dominique*0399.)

On my Kingspoint SC-60, Gamma operates only for values 0<x=<2. For example, Gamma (1.7) on SC-60 give same result as Factorial (0.7) on HP-15C, with same decimales digits.

Pr(X) give apparently same result as P(t) on a modern SHARP EL-506A. The SC-60 manual is infortunatly not in my possession.

Dominique