http://codex99.com/design/the-hp35.html
I found this site about the HP 35 history. I know that there are a lot of pages about the same matter and sorry if it was already posted here. I did not know how HP priced its products: the cost multiplied by a factor of "PI" or "e", that was curious to me. For those who do not know the page, it´s very cool.

This is an interesting blog. There are some most interesting claims. It would be helpful to have a list of annotated references - particularily from Hewlett, Packard, Cochran [etal] documents.

TomC

Great article!

I liked the company standard: selling price is (materials cost) * Pi !!!

Kevin

Thanks for that link @hibiki. I really enjoyed the read and it makes me think that I could learn a lot from reading HP history.

(06-17-2018 06:15 PM)mcquiggi Wrote: [ -> ]Great article!

I liked the company standard: selling price is (materials cost) * Pi !!!

Kevin

...or in competitive markets, list*

e...

Very interesting.

Thanks.

I found my HP 35 (serial # 1346A.....) at a flea market lost in a bunch of junk. It wanted I owned it because I never give a look to bunches of junk !

And it’s still alive !

(06-17-2018 06:15 PM)mcquiggi Wrote: [ -> ]Great article!

I liked the company standard: selling price is (materials cost) * Pi !!!

Kevin

If I took that phrase literally (Pi !!!), HP-50G calculates that to be 9.99999999999 E499. Somehow, I think even HP wouldn't be that crazy. Pi !! came to about 7380.55555766, and Pi! comes to 7.1881-ish, or so my HP-34C told me back in the day. That might be closer to the scale that HP was originally thinking of.

(Post 244)

(06-18-2018 12:02 AM)brickviking Wrote: [ -> ] (06-17-2018 06:15 PM)mcquiggi Wrote: [ -> ]Great article!

I liked the company standard: selling price is (materials cost) * Pi !!!

Kevin

If I took that phrase literally (Pi !!!), HP-50G calculates that to be 9.99999999999 E499. Somehow, I think even HP wouldn't be that crazy. Pi !! came to about 7380.55555766, and Pi! comes to 7.1881-ish, or so my HP-34C told me back in the day. That might be closer to the scale that HP was originally thinking of.

(Post 244)

Ha! I anticipated this interpretation so I put a space between Pi and the ‘!!!’ part!

Perhaps Pi!!! Was the government price!

Kevin

(06-18-2018 12:02 AM)brickviking Wrote: [ -> ] (06-17-2018 06:15 PM)mcquiggi Wrote: [ -> ]Great article!

I liked the company standard: selling price is (materials cost) * Pi !!!

Kevin

If I took that phrase literally (Pi !!!), HP-50G calculates that to be 9.99999999999 E499. Somehow, I think even HP wouldn't be that crazy. Pi !! came to about 7380.55555766, and Pi! comes to 7.1881-ish, or so my HP-34C told me back in the day. That might be closer to the scale that HP was originally thinking of.

(Post 244)

When did Pi become a natural number? Factorial is only defined for natural numbers.

(06-16-2018 10:58 PM)hibiki Wrote: [ -> ]http://codex99.com/design/the-hp35.html

I found this site about the HP 35 history. [...] For those who do not know the page, it´s very cool.

Indeed it is. Thank you very much, I've found it really interesting and an excellent read. Would love to find something similar about the HP-65.

V.

.

(06-18-2018 07:47 PM)Harald Wrote: [ -> ] (06-18-2018 12:02 AM)brickviking Wrote: [ -> ]If I took that phrase literally (Pi !!!), HP-50G calculates that to be 9.99999999999 E499. Somehow, I think even HP wouldn't be that crazy. Pi !! came to about 7380.55555766, and Pi! comes to 7.1881-ish, or so my HP-34C told me back in the day. That might be closer to the scale that HP was originally thinking of.

(Post 244)

When did Pi become a natural number? Factorial is only defined for natural numbers.

While that's true, certain factorial implementations (hp34c, HP48-series, HP-50G and others) interpolate non-integer results by using the Gamma function, as the factorial function is merely the integer-based special case of the Gamma function. Pretty much: \( n! = Γ(n+1) \), if I remember rightly, and I'm sorry if I can't get that Gamma to come out correctly. I had fun trying to generate the inverse... of course that's not defined anywhere mathematically, so I was told.

(Post 245)

@hibiki, thanks for the link. I knew about this site but this article has been updated in May 2018 with much more detailed information than previously.

Edit: here is the link to the

original article from 2012.

The middle section of

this video is about the HP-35 - "Death of the Slide Rule"

See also this archived site, presenting an article from 1972

Made in USA...finally!
(06-18-2018 11:05 PM)brickviking Wrote: [ -> ]Pretty much: \( n! = Γ(n+1) \), if I remember rightly, and I'm sorry if I can't get that Gamma to come out correctly. I had fun trying to generate the inverse... of course that's not defined anywhere mathematically, so I was told.

Do you mean something like

that?

I prefer Inverse Factorial, however:

120 XEQ InvFact -> 5

PI SQRT 3 * 4 / XEQ InvFact -> 1.5

163 ENTER ENTER + 1/x + ENTER * 5 * 18 / XEQ InvFact XEQ InvFact -> 3.14159265359

(On Free42)

00 { 89-Byte Prgm }

01▸LBL "InvFact"

02 ENTER

03 LN

04 SQRT

05 0.16

06 RCL× ST L

07 X<>Y

08 2.21

09 ×

10 +

11 0.194

12 +

13 2

14 X<Y?

15 X<>Y

16 X<> ST T

17▸LBL 00

18 R↓

19 R↓

20 STO ST Z

21 X<>Y

22 STO ST T

23 GAMMA

24 ÷

25 +/-

26 1

27 +

28 R↑

29 RCL+ ST T

30 1/X

31 RCL ST T

32 LN

33 STO- ST Y

34 X<> ST L

35 R↓

36 +/-

37 ÷

38 STO- ST Z

39 ABS

40 1ᴇ-30

41 X<Y?

42 GTO 00

43 R↑

44 1

45 -

46 END
(06-18-2018 12:02 AM)brickviking Wrote: [ -> ] (06-17-2018 06:15 PM)mcquiggi Wrote: [ -> ]Great article!

I liked the company standard: selling price is (materials cost) * Pi !!!

Kevin

If I took that phrase literally (Pi !!!), HP-50G calculates that to be 9.99999999999 E499. Somehow, I think even HP wouldn't be that crazy. Pi !! came to about 7380.55555766, and Pi! comes to 7.1881-ish, or so my HP-34C told me back in the day. That might be closer to the scale that HP was originally thinking of.

(Post 244)

I am curious - How did you parse that expression?

X!! Is not the same as (X!)! If you have heard of double-factorials, although of course it is if you haven't, ! Being an ambiguous mathematical symbol.

Is that x!!! (A triple factorial?)

(X!!)! (Factorial of a double factorial)

(X!)!! (Double factorial of a factorial)

((X!)!)! (Factorial of a factorial of a factorial)

(06-19-2018 10:22 AM)StephenG1CMZ Wrote: [ -> ] (06-18-2018 12:02 AM)brickviking Wrote: [ -> ]Pi !!!

I am curious - How did you parse that expression?

X!! Is not the same as (X!)! If you have heard of double-factorials, although of course it is if you haven't, ! Being an ambiguous mathematical symbol.

Is that x!!! (A triple factorial?)

(X!!)! (Factorial of a double factorial)

(X!)!! (Double factorial of a factorial)

((X!)!)! (Factorial of a factorial of a factorial)

I'd vote for the

triple factorial interpretation. Although I noticed that Wolfram Alpha interprets it as (Pi !!)! instead, so it recognizes the double factorial but not higher-order multifactorials. Also interesting is that it appears to have an

analytic continuation of the double factorial; I wonder if such continuations exist for higher-order multifactorials as well?

(06-19-2018 10:22 AM)StephenG1CMZ Wrote: [ -> ] (06-18-2018 12:02 AM)brickviking Wrote: [ -> ]If I took that phrase literally (Pi !!!), HP-50G calculates that to be 9.99999999999 E499. Somehow, I think even HP wouldn't be that crazy. Pi !! came to about 7380.55555766, and Pi! comes to 7.1881-ish, or so my HP-34C told me back in the day. That might be closer to the scale that HP was originally thinking of.

(Post 244)

I am curious - How did you parse that expression?

X!! Is not the same as (X!)! If you have heard of double-factorials, although of course it is if you haven't, ! Being an ambiguous mathematical symbol.

Is that x!!! (A triple factorial?)

(X!!)! (Factorial of a double factorial)

(X!)!! (Double factorial of a factorial)

((X!)!)! (Factorial of a factorial of a factorial)

I parsed that as the following procedure would indicate:

\((((\pi!)!)!)\), therefore would have approximately been:

\(\pi! = 7.18808272898\)

\(7.18808272898! = 7380.55555766 \)

\(7380.55555766! = OVERFLOW \)(at least for my 50G)

And I'd have to check what on earth are double-factorials or triple-factorials. I haven't heard of such a beast.

(Later) Oh, so that's what those are. Interesting.

(Post 246)

(06-16-2018 10:58 PM)hibiki Wrote: [ -> ]http://codex99.com/design/the-hp35.html

I found this site about the HP 35 history. I know that there are a lot of pages about the same matter and sorry if it was already posted here. I did not know how HP priced its products: the cost multiplied by a factor of "PI" or "e", that was curious to me. For those who do not know the page, it´s very cool.

On a journey to get the story about HP35 and forward until the TITAN with the SATURN, i noticed your links in this stream.

The PI was once explained to me like this

1/3 for Components and MFG

1/3 for Cost of Sales / Admin

1/3 for Profits

(06-20-2018 07:31 PM)brickviking Wrote: [ -> ]I parsed that as the following procedure would indicate:

\((((\pi!)!)!)\), therefore would have approximately been:

\(\pi! = 7.18808272898\)

\(7.18808272898! = 7380.55555766 \)

\(7380.55555766! = OVERFLOW \)(at least for my 50G)

That’s a job for super-wp34s:

pi ! ! 1 + LNgamma 10 LN / IP RCL L FP 10^x —> 4.41316713166

x<>y —> 25345

=> ((pi!)!)! = 4.41316713166*10^25345
or, approximately,

490347/111110*10^25345
Notice that

(pi!)! ~ 66425/9 is much nicer.

PS: LOGGAMMA on the HP 50g gives a less accurate mantissa:

4.4131694182
(06-18-2018 07:47 PM)Harald Wrote: [ -> ] (06-18-2018 12:02 AM)brickviking Wrote: [ -> ]If I took that phrase literally (Pi !!!), HP-50G calculates that to be 9.99999999999 E499. Somehow, I think even HP wouldn't be that crazy. Pi !! came to about 7380.55555766, and Pi! comes to 7.1881-ish, or so my HP-34C told me back in the day. That might be closer to the scale that HP was originally thinking of.

(Post 244)

When did Pi become a natural number? Factorial is only defined for natural numbers.

The Gamma function is defined for reals (and complex numbers). It agrees with the factorial on the positive integers.