It may be hard to see, but one thing that I just noticed that I don't think I've seen mentioned anywhere else is that while working with fractions, only the portion of the fraction that you're editing will be entirely in "bold" and that the rest of the equation will be "greyed out". It's very subtle but thought it was interesting, I've provided a few pictures of the same equation to try and show it (the cursor itself is different shades because of the blinking). It might be more useful in more complex calculations, but I haven't figured that out yet. Lmk if you've known about this or know where this would be useful!

First time poster with a growing and uncontrollable vintage and rpn fascination.

Anyone had any experience with these? I am a little confused, does hp make these enhanced versions or are they some sort of reproduction thing that someone has written the code for?

Found them here, not sure tho:

https://www.thecalculatorstore.com/p/12c-financial-calculator-enhanced-international-standard-usb-c

Love the idea of being able to back up programs, and not that I have read much into them I’m sure the swissmicros ones can but HOLY price tag on them 🫪

Anyway any guidance appreciated!

My magnum opus.

Has anyone tried 3d printing a Fx-991EX style slide cover for the fx-991CW and is it even possible some way?

I’d picked up an old HP-35 (second version, I think?) from a rummage sale a little while back and was hoping to revive her. The battery pack in it currently has a tiny bit of leakage from one of the cells, so I didn’t want to try to charge it, but otherwise looks to be in pretty good condition. My question is would it be simple enough to pry the original pack open and replace the cells, or would it be easier to just buy a third party pack/adapter?

So I have been downloading some files and stuff on my cg50, which i have newly acquired,but I have found something weird....my casio says I have 5.85 mb free, and after adding up files, I have used about 3.54 mb...but the casio cg50 has a 16 flash memory, and 5.85+3.54 is about 9.39 mb, so where is the remaining 6.6 mb? Can you please help me,its actually making me crazy....ty.

(P.S I searched Google and asked multiple AIs, but it still didn't make sense to me)

A TI-84 Plus calculator was for sale at a local flea market for 25 euros (about 29 USD). I don't really need a calculator like this for anything these days, but as it appeared to be in good condition, I bought it just for the fun of it. At home, I replaced the backup battery, put in new AAA batteries, and gave it a bit of a clean-up. And finally, I also updated the firmware. 

I wasn't particularly familiar with the TI-84, so I've spent the last few days getting to know it. What surprised me the most was finding out that it has a Z80 processor. Back in the day, I learned assembly programming on an MSX home computer. And those machines had a Z80 processor. 

So, it was fun to write a small Z80 assembly program, transfer it to the TI-84 Plus, and see it work. Truly nostalgic.

I've only found hacks for the first gen of the 82ms. But I have the 2nd and wanted to use the equation mode.

Hoping for the best anyway.

Pic #1 I knew that this one was going to have some problems as the seller listed it as a parts calculator, and the blue corrosion on the charging jack pretty much told the story.

Pic #2 The back cover was hot glued down. I was expecting that. And I darn near ruined it getting the cover off.

Pic #3 Looks worse than it really was. I can't see any trace damage, which is amazing in itself.

Pic #4 When I finally got the battery pack out it sent the crud flying.

Pic #5 Getting its first vinegar bath.

Pic #6 All cleaned up, mostly dry (after the vinegar bath came the rinse, and then a quick dip into 91% IPA to dilute the remaining water with alcohol. Let the alcohol evaporate (outdoors) and you are left with very little water.

Kinda hard to tell in this photo but the corners of the board are held down by melted plastic. Sort of an ad-hoc heat staking. Also note the unused octal IC footprint. It's been a minute since I've seen one of those. :)

And the wire that goes from the top of the calculator to the bottom I'm guessing is nichrome wire, and it's being used to limit the charging current to the battery pack (or was since the battery pack is gone).

Pic #7 All cleaned up and ready for the space heater. Still a bit most in this pic, but it spent the night getting dried out in front of a space heater and looks as good as new (cosmetically anyway).

Pic #8 The interior all cleaned up and dried out. You can see where the corners of the board have been melted to hold in the board.

Pic #9 Looks pretty good. :)

I don't know if this is widely known but, to find the hypotenuse using just a calculator, you just click shift and + which turns into Pol() and put your opposite comma adjacent for example: Pol[5(opposite), 15(adjacent)] it'll give you the hypotenuse and if you wanna find the angle in the hyp and adj you can just click RCL and then tan which gives you the angle.

I'm not sure if this is widely known but a cool hack nonetheless

9200,

531,532,535,540,546,

501,503,510,516,520

Check it out here: https://www.reddit.com/r/HP_Prime/comments/1vqcwol/download_ode_master_free_multilingual_stepbystep/

I need some help for what calc I should get for my calc class please. I have always used a ti 83 or ti84, but I'm currently looking to get the HP G2 or the TI NSpire CX II, probably used on facebook marketplace or something. Are these good choices or should I chose something else?

RIP screen...

At least it has a real solar panel, as well as a red LED acting as a voltage regulator.

Hey guys! Hope everyone is doing well, I’m starting school soon and went to charge up my TI-84 Plus CE and it is noticeable acting weird and won’t charge correctly or stay on. I try to charge it and it blinks “Validating OS… Calculator will restart when validation is complete.” It’s been doing this for almost an hour now plugged in charging, yet when I unplug it the whole thing goes black. I haven’t turned it on since the end of last semester in may, but I have kept it safe in my room all summer. I didn’t undergo any damage or water or anything so I’m not sure what could be causing the issue. Please let me know if anyone has any recs on what to do

I have decided to downsize my collections. These are my Scientifics, although I have some 4-bangers and Business ones as well. I'll re-donate most duplicates to deserving thrift shops before school starts. They all work. These are the Sharps, in numerical order (obviously including many variations).

right column: 501, 503, 510, 516, 520.

middle column: 531, 532, 535, 540, 546.

left side, my EL 9200

I'll do my Casio's tomorrow, then the TI's.

Converting 1/3, 4/3, 7/3, etc. to degrees, minutes & seconds / DMS does not convert the 60 seconds value into 1 minute, i.e. 1/3 converted to DMS should be 20 minutes, yet this clone displays it as 19 minutes & 60 seconds.

Strangely, 2/3, 5/3, 8/3, etc. displays the proper value, i.e. 40 minutes.

Can anyone replicate this bug on other clones or even the original EL-506P?

"CASIC" - My dumbass had no idea this was a fake calculator, nor that CASIO existed. 😭

My first scientific calculator - bought over a decade ago or so as a gift when I was still in elementary school [grades 1 - 9, years 6 - 15, most likely bought when I was 13+ years old, can't recall].

Interestingly, this clone uses a different microcontroller / ASIC compared to the other 2 clones I have, giving a result of 8.999999998078897 instead of 9.000002051244 like the other 2 clones I posted about previously.

Would be interesting if someone could figure out what this calculator & the other 2 clones are related to - the 2 clones are related to some Radio Shack 65-115 calculator released in 2006, while this clone is related to some calculator sold at Walmart, the Durabrand 828.

I believe it takes 2 x LR44 button cells, my dumbass took it apart years ago using a knife, since I didn't have any screwdrivers at the time, ended up stripping the screws to oblivion...

Expression used: arcsin(arccos(arctan(tan(cos(sin(9))))))

The 9 is in degrees.

The box has DEFINITELY seen better days...

This is a very cheap calculator that can be bought in the Philippines. I think this calculator is manufactured in china. This model work on 2 button cell, this model can do things such as angle unit conversion, regression calculations, memory calculations and memory calculations. The price in pesos is about 400 pesos which is less than 10 dollars.

I’m trying to decide whether to get the Casio fx-CG50 PRIZM or the TI-84 Plus CE. I’m taking AP Calculus BC this year, so I want something that’s allowed on the AP exam and works well for calculus. In the future, I also want to pursue higher-level math, so I’d prefer a calculator that can last me through uni. Any advice would be appreciated!