I have (2) TI 36X's and an 85. One of the 36x's is almost 20 years old and is still a work horse for me. Its been in mud, in rain, stepped on, rolled over, sat on (and we're talking some weight here boys & girls) and it keeps on calculating. I killed a 35 a few years ago by spilling soda on it but for $35 you can't beat them.
Here's how to decode your HP calculator serial number:
Numbers are in the format YYWWC##### where
YY
Is the number of years since 1960.
WW
Is the week (roughly) in which the unit was made. YYWW is not always exact and sometimes may have gone weeks or months without changing.
C
Is the country code: A = America (USA), B = Brazil, G = Germany, J = Japan, S = Singapore, M = Malaysia or Indonesia.
#####
The serial number within the specified week and year. (This is not included in the Earliest Serial Numbers section because all are assumed to start at 0 or 1.)
Example: The museum's HP-94F is serial number 2622J00025 indicating that it is the 25th unit made in Japan in the 22nd week of 1986.
HP 48GX and it is my work horse. The only thing that I have ever done was change the AAA's. It's about 15 years old and keeps on working when it dies I will be lost. I only have a TI-30 for thwe PE test.
Chris
"In this house, we obey the laws of thermodynamics." Homer Simpson
I use the TI-30 SLR every day for all of my calculations. It's a cheap and simple calculator. If I need something more powerful, I would probably do the calculation in MathCAD.
After burning through an assortment of Casios and TI's, I decided to take the plunge about 15 years ago to HP's. I started with a 32II (with a hard plastic carrying case, very slick), moved on to a 48GX and currently use it and a 35s.
The 48GX will solve equations with multiple unknowns that I can't even do on my desktop. It's a shame that Carly Fiorina de-emphasized the HP calculator business. It made me happy when she was fired. I think there's a still a place for top quality HP class calculators.
I keep replacing the batteries in my TI-30Xa. It works great. Has all the functions I need. It is not a high falutin' calculator like the high end graphing jobs. I am old school. Used slide rules when I was in college and my first jobs.