Calculators I actually use.

[knife31]

Hi everyone
I was looking at my collection and there’s a couple I don’t use at all. So decided to make a list of ones that I actually use for work, etc.…
1970’s thru 1980’s: HP-45/67/97, HP-11C, Jeppeson CR-2 Flt Computer (Circular Slide Rule).
Late 80’s thru early 90’s: HP-11C, HP-42
Mid 90’s thru 2000: HP-11C, Military E6B
Home Office: HP-42
Garage Office, HP-28S, HP-35S
On my person : (Depending on the day) HP-11C, PX11C/15C, Hemmi 32 Slide Rule, and now the DM15C Credit Card Calc.
Calc I use the least HP-18C
Calc used most for fun: HP-41CV
Wife uses a HP-12C. (she was at work and the big boss from corporate walked by and said “Wow you use a HP”, upped here creds with the staff.
For the ones that are just in my collection I need to start rotating them or at least pull the batteries.
Randy

[Maximilian Hohmann]

Hello!

(12-11-2024 07:35 PM)knife31 Wrote:  So decided to make a list of ones that I actually use for work, etc.…

My list is quite short compared to yours. The only one I really use is the smartphone app shown below that can add and subtract times (and nothing else). I only need that at work, so I don't make stupid mistakes when filling in logbooks. I would prefer to have it in hardware, but unfortunately nothing like it was ever made.
Of the other 1,000 calculators, I don't really us any, apart from occasionally trying one out, but this is all. What a waste of keys and displays!

Regards
Max

[John Garza (3665)]

Almost all of my machines are in storage.
Most of my mathematical work is done on spreadsheets these days, not calculators.
I do keep a small assortment of restored machines on hand in case I have the urge to use one or write a program. But that falls more under 'recreation' than anything else.

-J

[BobVA]

An HP-97 or my DM42/HP-25LP (with a printer) is still my best survival option for balancing my checkbook, or doing taxes. :-) So one of those is always on the desk for quick calculations. And as a bonus it keeps the printer on the '97 exercised.

I may make a new year's resolution to carry a real calculator in my bag. Plenty of good emulators, but I miss the click of the keys.

[Idnarn]

Hi Maximilian

(12-11-2024 09:42 PM)Maximilian Hohmann Wrote:  My list is quite short compared to yours. The only one I really use is the smartphone app shown below that can add and subtract times (and nothing else). I only need that at work, so I don't make stupid mistakes when filling in logbooks. I would prefer to have it in hardware, but unfortunately nothing like it was ever made.

https://imgur.com/a/U8ztecd

[John Garza (3665)]

And the HP-67/97 has an H.MS+ key...

[AnnoyedOne]

(12-12-2024 03:25 PM)John Garza (3665) Wrote:  And the HP-67/97 has an H.MS+ key...

As do many calculators.

The HP-12C does date addition/subtraction. Time probably not.

A1

PS:

Code:

1.25
g ->H
2.12
g ->H
+
f ->H.MS

[John Garza (3665)]

I thought of mentioning the fact you can write a program to do it with H.MS alone. But decided against it as anyone not willing to dig out a calculator from storage is probably not willing to program it. So I kept it simple.

[AnnoyedOne]

(12-12-2024 06:39 PM)John Garza (3665) Wrote:  I thought of mentioning the fact you can write a program to do it with H.MS alone.

Really? I'm intrigued. I've always used ->h and ->H.MS as above for time calculations.

A1

[John Garza (3665)]

H.MS+ and H.MS- are used to directly add/subtract time without having to convert to decimal hours, do the math, then convert back to H.MS format. I believe the HP-91, 27, 55, 65, 67, 97, and the 41C series had it. Probably some of the newer ones too.

And of course the 'hard way' of doing it involves slicing off digits with INT/FRAC and multiplication/division on machines without even H.MS conversions.
I'll leave that as an exercise for the CS majors out there...

-J

[c3d]

(12-11-2024 09:42 PM)Maximilian Hohmann Wrote:  My list is quite short compared to yours. The only one I really use is the smartphone app shown below that can add and subtract times (and nothing else). I only need that at work, so I don't make stupid mistakes when filling in logbooks. I would prefer to have it in hardware, but unfortunately nothing like it was ever made.

On SwissMicros DM32, DM42 or DM42n with DB48x / DB50x, the key sequence to perform the addition in your example is:

[1][.][2][5][.][ENTER]
[2][.][1][2][.][+]

The second dot transforms something like 1.25 into 1°25′_dms on the command line. You can obviously add seconds and, if you type one more [.], fractions of a second.

[bxparks]

(12-12-2024 10:36 PM)c3d Wrote:  On SwissMicros DM32, DM42 or DM42n with DB48x / DB50x, the key sequence to perform the addition in your example is:

[1][.][2][5][.][ENTER]
[2][.][1][2][.][+]

On RPN83P, this would be:

[{] [0] [,] [1] [,] [25] [ENTER]
[{] [0] [,] [2] [,] [12] [+]

The Duration object has 4 components {days, hours, minutes, seconds} which forces the initial 0.

If calculations with only 3 components (`hh:mm:ss`) are the most common, I suppose I could add a special case in the command line parser, to allow this to be entered as:

[1] [:] [25] [:] [ENTER]
[2] [:] [12] [:] [+]

[nickapos]

(12-11-2024 09:42 PM)Maximilian Hohmann Wrote:  Hello!

(12-11-2024 07:35 PM)knife31 Wrote:  So decided to make a list of ones that I actually use for work, etc.…

My list is quite short compared to yours. The only one I really use is the smartphone app shown below that can add and subtract times (and nothing else). I only need that at work, so I don't make stupid mistakes when filling in logbooks. I would prefer to have it in hardware, but unfortunately nothing like it was ever made.
Of the other 1,000 calculators, I don't really us any, apart from occasionally trying one out, but this is all. What a waste of keys and displays!

Regards
Max

Hp prime can also do this

[Steve Simpkin]

(12-13-2024 03:27 AM)nickapos Wrote:  ...
Hp prime can also do this

Here is an example of the keystrokes used for DMS calculations on the Prime:
https://www.hpmuseum.org/forum/thread-34...l#pid31084

[Steve Simpkin]

(12-13-2024 03:51 AM)Steve Simpkin Wrote:  

(12-13-2024 03:27 AM)nickapos Wrote:  ...
Hp prime can also do this

Here is an example of the keystrokes used for DMS calculations on the Prime:
https://www.hpmuseum.org/forum/thread-34...l#pid31084

A number of the Casio models such as the fx-115 and fx-991 series can do this as well. They feature an unshifted [° ' "] key that works similar to the shifted equivalent key on the HP Prime.
For example: 1 [° ' "] 25 [° ' "] +2 [° ' "] 12 [° ' "] = 3° 37' 0"

[Maximilian Hohmann]

Hello!

(12-12-2024 10:36 PM)c3d Wrote:  On SwissMicros DM32, DM42 or DM42n with DB48x / DB50x, the key sequence to perform the addition in your example is:

[1][.][2][5][.][ENTER]
[2][.][1][2][.][+]

The second dot transforms something like 1.25 into 1°25′_dms on the command line. You can obviously add seconds and, if you type one more [.], fractions of a second.

A smart way of doing it without (much) extra effort and one more reason to get one of these calculators.

(12-12-2024 03:25 PM)John Garza (3665) Wrote:  And the HP-67/97 has an H.MS+ key...

Yes, and because of that, the HP-67 is one of my favorite calculators. But not for practical everyday use. Too valuable and delicate to be carried around in a (flight) bag and left in a car or plane overnight. And then you need to carry a charger or a spare battery pack.

(12-13-2024 07:04 AM)Steve Simpkin Wrote:  A number of the Casio models such as the fx-115 and fx-991 series can do this as well. They feature an unshifted [° ' "] key that works similar to the shifted equivalent key on the HP Prime.
For example: 1 [° ' "] 25 [° ' "] +2 [° ' "] 12 [° ' "] = 3° 37' 0"

The famous "droplet key"... (the flying students call it „Tröpchentaste“ here) because the symbols look like small drops of water. This is actually a clever solution, the calculators are cheap and often solar-powered.

But Casio had something even better, the LC-403LU "Time Calculations":



If you press the "%" key with the "HMS" second function in the right moment, it switches to time mode permanently (until turned off at least). No extra keystrokes required from there on, all inputs are treated as H.M(.S) values. Just like my smartphone app.
I carried this calculator with me for about a decade, but it has developed an issue with battery contacts and display segments and I had to retire it to the collection. These calculators are quite rare now and unfortunately there never was a successor. Currently there are only two on eBay worldwide and each would cost me over 50 Euros if I include shipping and import duties...

Regards
Max

[AnnoyedOne]

(12-12-2024 08:58 PM)John Garza (3665) Wrote:  H.MS+ and H.MS- are used to directly add/subtract time without having to convert to decimal hours...

I'd never heard of those functions before but you're right.

Quote:Time calculations could be done directly with the H.MS+ and - functions, or times could be converted to/from decimal hours.

https://www.hpmuseum.org/hp55.htm

Interesting.

As for the "hard" method I've always owned a calculator with ->H and ->H.MS functions I'm lazy.

At the time I purchased a HP-15C the HP-41C was about 3x the price and the base calculator seemingly had less functions. So...

A1

PS: FYI reading p96 (p100 in the PDF) of

HP-67 Owner's Handbook and Programming Guide (00067-90011, Rev. E, 10-78)

in the section "Adding and Subtracting Time and Angles" explains the H.MS+/H.MS- functions very well.

[naddy]

(12-11-2024 07:35 PM)knife31 Wrote:  So decided to make a list of ones that I actually use for work, etc.…

Things have been very much in flux since I discovered the HP-15C CE a few months ago, which rekindled my interest in HP calculators. As of the moment of writing, both my HP-15C and CE are in Barcelona for servicing, and my go-to calculator is an HP-32S.