Large characters


Senior Member
I inadvertenly hit some keyboard combination and i have now large characters that i could not get rid of, how do go back to normal?Large.jpg


Technical Support
Staff member
Hold the Control key and press "-" (minus) key to decrease font size
Hold the Control key and press "+" (plus) key to increase font size
Hold the Control key and press "0" through "9" keys for a specific font size


Senior Member
Hi Everyone
I inadvertenly hit some keypad combination and look what I did to my calculator! I held Control (+...-) nothing changed!
Anyway its been a while since I had time to add my horrible knowledge ...just for fun ...other then the (+) sign on the calculator there is only one other key that has not been changed and I would never know it if I didn't take it apart and use it for my billing because I do charge by the hour :)
Any way hopefully this winter I can FIND time and get more projects done with your help
your unknowledgable friend



Technical Support
Staff member
The Sinclair Scientific was a gem which appeared broken without moving keys about. It was the safest calculator to leave lying around at school as anyone who 'borrowed it' soon returned it, totally mystified by the lack of any "=" button.

That used Reverse Polish Notation (RPN) for calculations which was something of a pain to use. I still have mine though, being over 45 years old, it's now worse for wear. The battery contacts suffer stress fractures and snap off while the power switch was a slide-over-PCB-pad affair which wears away the pads - That's the blue spigot with metal flanges between the upper left battery contacts.

I still think it's a beautifully-styled design.


Senior Member
...That used Reverse Polish Notation (RPN) for calculations which was something of a pain to use ....
I had one, and RPN was a pain to use, but I can now go one better.

Somewhere in my loft I've got a Russian rip-off of an HP calculator from back in the day.

It uses RPN, and all the keys are in Cyrillic.


Well-known member
I jumped at the HP-21 when it came out. RPN was super-fast for tests in school and then on to engineering projects, and I still have it somewhere around here. (RPN is actually called postfix notation. Interesting read at The Museum of HP Calculators.)


Senior Member
@ Hippy that is a cool calculator ... i never seen/used one like it and would have did the same (gave it back) if i tried to borrow it... but used many with the old red led display

@ techElder its funny how things were back in the day if my kid went to school with the HP-21 ...they'ed think its a windup typewritter.

Since I am here ...I friend of mine gave me some none working 125w led grow lights the corn bulb style and one of them has no driver at all! just wires to the in series 28 leds in strips which is totally unsafe and prolly a scam ...but they have colors like red blue and white question is ...are the grow leds the same as any leds like blue or red etc? or are they special leds ... now that i has grow leds ...North Dakota is going to be growing some picaxed controlled trees the wind speeds slow down to the lower 55 mph range :)