A community centered around handheld calculators. Show off your collections, ask questions, or trade benchmarks and torture tests.
Icon snagged from here.
Found my old grade school calculator while going through some drawers. It's not programmable or retro (yet) or valuable, but it served me well for many, many years.
Pretty sure I learned the pattern for incrementing binary numbers on this thing while I was sitting bored in study hall before I even knew what binary was.
Spotted this at my local flea market. My first VFD display!
Yes it might not appear to align right, but that's only because the ruler is slightly above the calculator.
My calculator is exactly 178mm long, which is the definition of the length of one banana...
http://bananaforscale.info/#!/convert/length/1/bananas/millimeters
I couldn't find the exact pixel dimensions for this calculator, so I just measured it myself.
1 Centimeter = 22 Pixels, exactly.
Edit: It might not appear in the photo to be an exact alignment with centimeters, but that's all because of the ruler sitting a little higher than the screen and the camera optical focus and crap.
Indeed, it's exactly 22px/cm
Yes, 355÷113 is very close to π, but is not equal to π
So how does it get things 'right' for cos(355÷113), but not right for sin(355÷113)?
And why is the error of π-355÷113 exactly the same as the error of sin(355÷113)?
I sense some fuckiness of how they handle π...
The calculator as a whole seems to work perfectly, but can anyone explain Casio's choice of the shape of their flashing text entry cursor?
Does anyone happen to know where to find the manual or additional info on this calculator? I found very little info on this site, but that was it (http://www.calcuseum.com/SCRAPBOOK/BONUS/15091/1.htm)
The electronics seem to work, but the printer only feeds up to a certain point, where the paper is right below the ribbon. Then it stops feeding even when I press the up button. If something is wrong with the printer, I admit that I don't know where to start with troubleshooting it. The metal parts that push the ribbon against the spinning numbers also don't move at all, but the two plastic wheels spin the ribbon around.
I've tested all configurations of the switches above the keypad, and I can't seem to turn off the printer either. That probably is just a result of me not knowing how to use it though. If anyone has troubleshooting advice or even just ideas on what sources to use for further research, it'd be much appreciated!
It's the one on the left. We're allowed any calculator that's not programmable and cannot store text. The Elektronika can be programmed though it cannot store a program when turned off.
Nevermind the Casio's ability to solve, integrate, derivate, deal with complex numbers and matrices and more
cross-posted from: https://lemmy.world/post/23724729
My dad says he's never replaced the battery in it. We saw this in a home video and laughed when we found the still uses it 40 years later.
For testing:
The official Swissmicros 2-line firmware dropped on the Winter Solstice as an early Christmas present. It also has a nice set of constants and conversions.
I'd been toying with the idea of what RPN calculator a kid could use at school here in the UK. I thought the sticking point would be that most RPNs are programmable, but turns out that isn't an explicit exclusion on the JCQ calculator guidance for GCSE and A-level exams. They can also use graphic calculators. There is a hard no on CAS. The HP-15c seemed the least likely to cause issues with invigilators, so went for this. We'll have to see if it works out though.
This is the calculator that my father bought for his senior year of high school in 1974. He showed it to me when I was four and I remember being amazed that a little box could add and subtract, captivated by the tiny red numbers. It was a few months later that he brought home our first computer, a Texas Instruments TI-99/4A, and I was again smitten. So much of the trajectory of my life can be traced back to those two objects.
When I opened the unit up I was not too terribly surprised to see a set of four AA batteries from the late 80's still installed, but I was very lucky that they hadn't leaked. I popped a new set in and it powered on with no issues. I played with it for a moment, the first time I had ever pushed the buttons on it, and placed it in the closet. I know it will be the perfect phylactery when I become a lich.
The HP-65 was not only HP's first programmable scientific, but it could also read and write magnetic cards. There were several 'pac's of cards allowing it to tackle financial, astronomical, aviation, electrical and other speciality field calculations. The buttons were double shot and have a lovely tactile click. The red LED screen is remarkably crisp and easy to read.
These are the tests which can give you quite a good profile and accuracy rating for your financial calculator. Any more contributions and confirmation are very much appreciated and I will update the swissmicros page (though I may need to move it off there at some point).
| # | Ref | N | I%YR | PV | PMT | FV | P/YR | Mode |
|----|------------|--------------|-----------|----------|--------------|-----------|------|-------|
| 1 | DM | 38 x 12 | 5.25% | 270'000 | ? | 0 | 12 | end |
| 1b | DM | 38 x 12 | ? | 270'000 | -14'584/12 | 0 | 12 | end |
| 2 | SlideRule | 360 | 15% → 12% | 100'000 | ?-? | 0 | 12 | end |
| 3 | Kahan 1983 | 60x60x24x365 | 10% | 0 | -0.01 | ? | =N | end |
| 4 | DM | 480 | 0 → ? | 100'000 | ?→ PMT | 0 | 12 | end |
| 5 | Dieter | 10 | ? | 50 | -30 | 400 | 1 | end |
| 6 | Dieter | 10 | ? | 50 | -30 | 80 | 1 | end |
| 7 | A Chan | 10 | ? | -100 | 10 | 1e-10 | 12 | end |
| 8 | Miguel | 32 | ? | -999'999 | 0 | 1e6 | 1 | end |
| 9 | DM | ? | 25 | 100000 | -2083.333334 | 0 | 12 | end |
| 10 | DM | ? | 25 | 100000 | -2040.816327 | 0 | 12 | begin |
| 11 | robve | 60x24x365 | 1/6% → ? | 0 | -0.01 | ?→ FV | =N | end |
| 12 | robve | 40 | ? → I%YR | 900 | -400 | -1000 → ? | 1 | begin |
2: https://www.hpmuseum.org/forum/thread-20707.html
3: https://www.hpmuseum.org/forum/thread-1012.html
5, 6: https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv021.cgi?read=234439
7: https://www.hpmuseum.org/forum/thread-18359-post-161549.html#pid161549
8: https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv017.cgi?read=120592
11, 12: https://www.hpmuseum.org/forum/thread-16565-page-2.html
Puzzle 2 is from here, and needs you to calculate PMT given n = 360, I%YR = 15%, PV = 100'000, FV = 0, then calculate PMT, but with I%YR = 12%. Subtract the two results, and put that back into PMT, then change n = 36 and I%YR = 15% again, and calculate PV.
Puzzle 3: you may need to divide I%PY by N depending on how your calculator handles i vs I%YR and what the limit is on P/YR.
Puzzle 4 needs you to calculate PMT first given I%YR = 0, then re-input this back into PMT and calculate I%YR. On the HP-12c this is best done by pressing x<>y twice before putting back into PMT.
Puzzle 11: calculate for FV first, re-input back to FV and compute I%YR.
Puzzle 12: calculate for i first, re-input back into i and compute FV.
The other puzzles are just a solve for '?'.
They can be a bit confusing, so I also did a couple of videos here and here solving them on a DM-42 and HP-12c.
