Doubt with exponents input in early HP35.

[isanchez]

Dear friends,
just to verify if my HP35 behaviour is normal when using exponential notation.

I have an early HP35 serial 1142Sxxxx, with the bug (ln2.02). It works great (supposedly), but different to other 35 later models, when using exponents.

I.e., to enter 3.0E-08, I have to press the following key sequence:
"3" the display shows: "3.0"
(exp)(chs) the display shows: "3.0" (no exponent "00" figures at all)
"8" the display shows: "3.0 -08"

so, the display only shows "3.0" until I enter the "8" in the sequence, only then "3.0 -08" is shown.

It doesn't allow to modify the exponent sign y pressing CHS...

In other HP35 (later models) right after pressing "EXP", the 00, in the extreme right of the display, are shown, then you can input the exponent figure and the sign. And even change the sign with the CHS key....

Do you know if this is the normal behaviour in these first models?

Thanks and kind regards

Ignacio

[EdS2]

Ashley Feniello's emulator runs in the browser and uses the original microcode or the fixed microcode, so you can compare. (Source on github.)

[isanchez]

Thanks Eds2!
The thing is that in all the rest of Hp35 I own and even in the User Manual the behaviour is different than in this early model.
the exponents "00" are shown right after "EXP" key is pressed, then you can "CHS" & enter the exponent figure. CHS can be pressed before or after entering the exponent figure.

[Didier Lachieze]

(02-07-2018 10:19 AM)isanchez Wrote:  Do you know if this is the normal behaviour in these first models?

This is how it is described in the HP Journal from June 1972:

Quote:The enter-exponent key, EEX, is used for entering numbers in scientific notation. For example, the number 612,000 may be entered as 6.12 EEX 5 or 612 EEX 3 or .0612 EEX 7 as well as 612000. The change-sign key, CHS, changes the sign of the mantissa or, if pressed immediately following EEX, the sign of the exponent.

[Jeff O.]

(02-07-2018 10:19 AM)isanchez Wrote:  Dear friends,
just to verify if my HP35 behaviour is normal when using exponential notation...

...Do you know if this is the normal behaviour in these first models?

Thanks and kind regards

Ignacio

The S/N 1143A5xxxx unit (with the ln 2.02 bug) I have at hand right now exhibits behavior between what you describe for yours and for the later models:

"3" - the display shows: "3."
(exp) - the display shows: "3." (no exponent "00" figures at all)
(chs) - the display shows: "3._____-00"
"8" the display shows: "3._____-08"
(chs) - the display shows: "3._____-08" (chs has no effect)

I do not have a later model 35 handy, but the 45 I have on hand exhibits (I believe) the behavior of later models, :

"3" - the display shows: "3."
(exp) - the display shows: "3._____00"
(chs) - the display shows: "3._____-00"
"8" - the display shows: "3._____-08"
(chs) - the display shows: "3._____08" (chs changes sign of exponent)

or:

"3" - the display shows: "3."
(exp) - the display shows: "3._____00"
"8" - the display shows: "3._____08"
(chs) - the display shows: "3._____-08" (chs changes sign of exponent)

[isanchez]

Hi Jeff,
Yessss! You are right! Sorry, i wrote the message by heart. The behaviour is exactly as you mention for your older HP35 calculator.
I have checked It a few moments ago.
The more recent HP35 models do behave like HP 45 you mention.
Thanks!!!!
Kind regards
Ignacio

[Michael de Estrada]

Yes, indeed, the Red Dot and early version 2 HP-35 with The Bug require the sign of the exponent to be entered before the value, and do not toggle with CH S. Later versions work “normally” with the CH S able to toggle the sign after the value is entered.

[isanchez]

Hi,
Thanks everybody!
Very clarifying inputs!
I was not aware of this behaviour, so I got very surprised, and firstly thought it was not working properly.
Thanks again!

My calculator comes for Singapur and implements de ln2.02 bug. I thought this bug was only present in USA made models, but no. Mine also has the back label in German with a couple of mistakes (detected also in early non-English labels)

Kind regards
Ignacio

Ignacio

[AndiGer]

On the German label you posted in the picture of the calc here
http://www.hpmuseum.org/forum/thread-9846.html
There is written that CHS must be entered first.
That's true with the older versions of the HP-35.
In newer version you can enter CHS also later. Guess the label was never adopted. Have a 1302S here that has this on the label as well.

Another interesting thing with CHS is documented under the description of the HP-35 on this website:
"The HP-35 allowed the user to press the CHS sign before or during number entry. If a number was in the display as a result of something other than digit entry, pressing CHS negated it, but if the CHS key was then followed by a digit, the calculator assumed the CHS was actually meant for the following entry. Thus the previous number displayed was pushed onto the stack without the (already displayed) sign change. This feature could be confusing and later models required the CHS key to be pressed after the first digit of a number."

Andi