The HP70 and it's limitations.
01-26-2018, 09:43 PM
Post: #1
 Harald Senior Member Posts: 657 Joined: Dec 2013
The HP70 and it's limitations.
Have you ever tried to calculate the square root on an HP 70? First you realise "oh, there is no sqrt key!". Then you think "ah, there is y^x". So you type a 2 and go in search of thea 1/X key. But you can't find it. So you hit enter, 1, /, y^x and finally get a result. But oh no... you pushed something off the stack... then you start wondering:
Ok, admittedly the HP 70 was never intended for engineering use, maybe there is no need for sqrt. But 1/X?!? Is that really never needed by financial people?

Any thoughts? I am still wondering...

Cheers,
Harald
01-26-2018, 10:08 PM (This post was last modified: 01-26-2018 10:09 PM by SlideRule.)
Post: #2
 SlideRule Senior Member Posts: 901 Joined: Dec 2013
RE: The HP70 and it's limitations.
Perhaps

4; Enter; 0.5; Y^x
or
4, Enter, 1, Enter, 2, /, Y^x
etc.

SlideRule

am I missing something?
01-26-2018, 10:08 PM
Post: #3
 Maximilian Hohmann Senior Member Posts: 602 Joined: Dec 2013
RE: The HP70 and it's limitations.
(01-26-2018 09:43 PM)Harald Wrote:  Any thoughts? I am still wondering...

It's all there: 1/x = y^-1 and sqrt = y^.5 :-)

BTW: There are contemporary financial calculators like this Victor V14 which do not even have y^x. It's either financial or nothing...

01-26-2018, 10:47 PM
Post: #4
 Harald Senior Member Posts: 657 Joined: Dec 2013
RE: The HP70 and it's limitations.
(01-26-2018 10:08 PM)SlideRule Wrote:  Perhaps

4; Enter; 0.5; Y^x
or
4, Enter, 1, Enter, 2, /, Y^x
etc.

SlideRule

am I missing something?

You are not missing anything, it is all there.
It is just that I forgot about square root not being available. So my next thought was y^(1/2). I usually prefer entering 0.5 as 2 1/X, don't ask me why, I don't know. And in attempting that I forgot 1/X isn't there either.
Both sqrt and 1/X are functions I use a lot. So it always surprises me they have been left of the HP 70.
01-26-2018, 10:50 PM
Post: #5
 Harald Senior Member Posts: 657 Joined: Dec 2013
RE: The HP70 and it's limitations.
(01-26-2018 10:08 PM)Maximilian Hohmann Wrote:
(01-26-2018 09:43 PM)Harald Wrote:  Any thoughts? I am still wondering...

It's all there: 1/x = y^-1 and sqrt = y^.5 :-)

BTW: There are contemporary financial calculators like this Victor V14 which do not even have y^x. It's either financial or nothing...

I would have tried ln 2 / e^x, but ln and e^x aren't there either.
Still, I am glad I have a 70
01-27-2018, 12:50 AM
Post: #6
 Michael de Estrada Senior Member Posts: 335 Joined: Dec 2013
RE: The HP70 and it's limitations.
Get a Victor V12. It’s all there, and RPN too.
01-27-2018, 02:43 AM
Post: #7
 Joe Horn Senior Member Posts: 1,478 Joined: Dec 2013
RE: The HP70 and it's limitations.
The HP-70 Manual, page 27, says to use 25 ENTER 1 ENTER 2 [÷] [y^x] to get the square root of 25.

<0|ɸ|0>
-Joe-
01-27-2018, 12:20 PM
Post: #8
 Maximilian Hohmann Senior Member Posts: 602 Joined: Dec 2013
RE: The HP70 and it's limitations.
(01-26-2018 10:50 PM)Harald Wrote:  Still, I am glad I have a 70

Me too. One of the real difficult ones to find.

By the way: Its "big brother", the HP-80 does not have sqrt and reciprocal either. And the HP-22 has sqrt but no 1/x. The first HP financial calculator which has them both must be the HP-27 (which is not a pure financial calculator) and the HP-37.
01-27-2018, 02:07 PM (This post was last modified: 01-27-2018 02:10 PM by Massimo Gnerucci.)
Post: #9
 Massimo Gnerucci Senior Member Posts: 1,778 Joined: Dec 2013
RE: The HP70 and it's limitations.
(01-27-2018 12:20 PM)Maximilian Hohmann Wrote:
(01-26-2018 10:50 PM)Harald Wrote:  Still, I am glad I have a 70

Me too. One of the real difficult ones to find.

By the way: Its "big brother", the HP-80 does not have sqrt and reciprocal either. And the HP-22 has sqrt but no 1/x. The first HP financial calculator which has them both must be the HP-27 (which is not a pure financial calculator) and the HP-37.

Another one with a 70

The HP-80 does have sqrt (shift y^x).

Greetings,
Massimo

-+×÷ ↔ left is right and right is wrong
01-27-2018, 02:43 PM
Post: #10
 rprosperi Senior Member Posts: 3,564 Joined: Dec 2013
RE: The HP70 and it's limitations.
(01-26-2018 10:50 PM)Harald Wrote:  Still, I am glad I have a 70

Me too! Of all the machines I've acquired that are too disappointing to use, this one made me the happiest. The limited feature set (compared to HP-80) is clearly why this machine was not popular, did not sell well and was quickly discontinued. The garish color scheme and unusual keyboard layout (CLX on bottom right!?!?!) surely didn't help either.

Still, I too am glad I have a 70! It's endearing in an ugly child kinda way.

--Bob Prosperi
01-27-2018, 03:21 PM
Post: #11
 Michael de Estrada Senior Member Posts: 335 Joined: Dec 2013
RE: The HP70 and it's limitations.
(01-27-2018 12:20 PM)Maximilian Hohmann Wrote:  By the way: Its "big brother", the HP-80 does not have sqrt and reciprocal either.

Incorrect. The HP-80 does have the sqrt function (yellow shift y^x), so it does not require the reciprocal operation to compute a square root.
01-27-2018, 06:33 PM (This post was last modified: 02-04-2018 05:23 PM by aurelio.)
Post: #12
 aurelio Senior Member Posts: 379 Joined: Dec 2013
RE: The HP70 and it's limitations.
anyway one of the most beatiful calculators ever made, the orange colour of the keyboard in lovely contrast with the military green/grey of the body
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