calculators without OFF

[vaklaff]

Accidentally I ran into the opening post of one old thread:

Quote:"Hewlett-Packard HP-15C calculator. I bought this new in July, 1985 ... The only real problem that I know of is that I can't turn it off unless I pull a battery. I don't see any 'off' function on the keyboard and I don't know if this has an auto-off feature after so many seconds of non-use."

("Ok... Own up! Who amongst you put this 15c description on eBay?")

The text and especially the subject gave me a good laugh. But then I realized I do have a calculator without any OFF function - CATIGA CS-110:
my picture
the manufacturer's page

There's no way to switch it off. It does it itself after something like 5-7 minutes of inactivity. Or just pull the batteries :-) Do you know other calculator without OFF?

Václav

[Maximilian Hohmann]

Hello!

(09-13-2020 05:05 PM)vaklaff Wrote:  Do you know other calculator without OFF?

One of the newer ones from HP would be the HP-6S Solar. It will turn itself off when the sun goes down :-)

Regards
Max

[Thomas Okken]

The HP-41C doesn't have OFF printed anywhere on the keyboard, either. And yet, I have always managed to turn mine off whenever I wanted to, without waiting 10 minutes. I don't remember having issues turning off my HP-10C and 16C, either, back in the day.

[vaklaff]

(09-13-2020 05:38 PM)Maximilian Hohmann Wrote:  Hello!

(09-13-2020 05:05 PM)vaklaff Wrote:  Do you know other calculator without OFF?

One of the newer ones from HP would be the HP-6S Solar. It will turn itself off when the sun goes down :-)

Regards
Max

Ah, of course, solar models! TBH I dislike them and currently don’t have any...

[vaklaff]

I’ve found several equivalents to the Catiga, e.g. TOOR TR-523. The only exception is the topmost pair of buttons: OFF and LRN. Funnily enough, the manual doesn’t mention the LRN key at all.

[vaklaff]

(09-13-2020 05:55 PM)Thomas Okken Wrote:  The HP-41C doesn't have OFF printed anywhere on the keyboard, either. And yet, I have always managed to turn mine off whenever I wanted to, without waiting 10 minutes. I don't remember having issues turning off my HP-10C and 16C, either, back in the day.

Yeah, yeah :-) I take my question back. My second attempt is: Do you know any calculator running on batteries that can’t be switched off from its keyboard?

[ijabbott]

My Casio fx-115D (dual powered, solar + battery) has no 'off' function apart from auto power off, or covering the solar panel if the battery is dead. I think the same is true for all the Casio "C-Power" calculators. There are some that have two 'on' buttons and no 'off' button!

[Dave Britten]

Most of the Casio fx-xxxW series with solar power (like the fx-115W) have no Off key, just the auto power off.

The purely-solar-powered TI-36X Solar (not Pro) and the Casio fx-260 Solar don't turn off at all if the solar panel is receiving adequate light. The Casio tends to power up gracefully, but the TI often needs a press of ON/AC to clear up a glitchy display and reset the machine. I believe the Casio CM-100 and other models that share that body style are the same way.

[Eddie W. Shore]

Most solar calculators of the 1980s and 1990s do not have an OFF button.

For the landscape HP calculators, such as the HP 41C, 11C, 12C, 15C, and 16C, the ON acts as both the ON and OFF key. That may be the case with the first Catiga calculator as well, not sure.

Side note: calculators such as the TOOR have a large screen but emulate the Casio fx-6300g and HP 9g have a small graphing calculator screen with no way to enlarge the graphing screen. I find that kind of annoying.

[johanw]

(09-13-2020 05:05 PM)vaklaff Wrote:  Do you know other calculator without OFF?

My old Casio fx-98 Solar. It remains ON while there isenough ligt to power it. And I have some cheap 4-function credit card sized solar calculator that behaves the same.

[vaklaff]

(09-14-2020 01:10 AM)Eddie W. Shore Wrote:  Most solar calculators of the 1980s and 1990s do not have an OFF button.

For the landscape HP calculators, such as the HP 41C, 11C, 12C, 15C, and 16C, the ON acts as both the ON and OFF key. That may be the case with the first Catiga calculator as well, not sure.

No, it isn't. When on, the button serves as Clear. I have a few HPs without OFF but so it was the first thing I tried :-) This Catiga was a flea market buy, without docs, long time ago. The missing OFF or anything acting like it baffled me. I tried everything I could think of, then searched the Internet for its manual (no luck). In the process I found a few 1:1 equivalents (TOOR TR-523, Procalc SC1000, Graph-09XC). They match every button and every label, except OFF and that LRN which seems useless. By the way, I used the TOOR's manual to learn the Catiga.

To my knowledge this is the only model of a battery-only powered calculator without an OFF or equivalent. My guess is the OFF and LRN pair was cut off for slightly cheaper production a maybe the smaller/nicer case.

Quote:Side note: calculators such as the TOOR have a large screen but emulate the Casio fx-6300g and HP 9g have a small graphing calculator screen with no way to enlarge the graphing screen. I find that kind of annoying.

I happen to own fx-6300g too. Not only the display is small but the graphing area is just part of it IIRC :-) I don't actually care about graphing but I imagine that limited display must upset people who do...

I bought the Catiga without really inspecting it. It was pretty cheap (3$ or so), at first glance a Casio knock-off, looked cute enough and most of all, I spotted "PROG" on the keyboard. Only later at home I found out it isn't "properly" programmable, you can just enter a list of formulae in it. And I couldn't find any Casio 1:1 equivalent. It ended up in the lowest drawer until today when I read the "Own up!" post.

[Albert Chan]

Early this year, I bid for Sharp EL-506W, for 50 cents ... and won ! (total price w/ shipping + tax = $3.73)
However, it seems to turn on by itself, whenever there is light.

Turns out button cell spring contact is weak. Calculator was running on solar only.
I fixed it by padding cardboard on top of button cell, then screw tight the cover.

Now, it run perfectly

[robve]

(09-13-2020 05:05 PM)vaklaff Wrote:  Do you know other calculator without OFF?

TI-36X Solar.

This is a solar calculator without battery backup, thus not really surprising to lack an OFF button. But I wonder if this isn't the case for all solar calculators without a backup battery? Is there any point to adding an OFF button?