A gift from my Calculus teacher upon graduation.
Yes manual included. Sadly the 0 (zero) button no longer works, due to battery corrosion… ☹️
I had one of these in highschool in the 90s! Mine was either the 82 or the 85 I can’t remember now since that was like 25 years ago lol
You might have gotten an 83, as it fixed some sort of issue with the 82
Probably the 0 button going bad XD
IIRC, the 83 model fixed some issue with the accuracy of fractions or something like that.
Already said that in my original post, but thank you Mr Quicksand!
I might manage to fully fix it one day, I think it’s a corroded via.
You mean with a 5 button zero
(1-1)LOL, I like the way you think 👍
Open that bad boy up and grab some vinegar and a qtip. It’ll remove the corrosion!
Already been there and basically done that actually, but with rubbing alcohol and a pencil eraser.
If vinegar is used (yes I’ve done that before as well), then it needs to be followed by a baking soda/water solution to neutralize the acid.
I believe the remaining problem is a corroded via, which connects the layers of the board together.
It’s only a 2 layer board, so I might get it fully fixed one of these days. Totally within my skill set, just not high on my priority list…
Humanity went centuries without 0s, you’ll probably be fine!
LMFAO!
I actually did two videos on my two rounds of trying to restore this thing…
https://youtube.com/watch?v=im33lQ2To_Q
https://youtube.com/watch?v=CwX4KItBJjU
More to come, maybe, someday…
That’s a damn shame about the corrosion, given that the outside of the device is in pristine condition.
One extra unusual thing about this particular calculator, Texas Instruments didn’t even bother to etch a serial number on the back. And these calculators didn’t use stickers for the serial number, they melted the numbers right into the plastic. But mine, blank.
The only thing they put on the back of mine is a big capital R above the serial number field. It took me a bit of research to find out what that means.
It’s a refurbished unit straight from Texas Instruments.
