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I think I bought this (at the time, to me, the best invention in the Universe) in 1971. No more trig tables! Needs battery pack.
How many of y’all remember using trig tables, and what we did with them???? ????
What is the difference with the HP48 & HP48?
There were several different versions of the HP48
The main difference was the number of card slots in the calculator
The HP48GX had two, one for a program card and one for saving data files for different projects.
I was going to say “I’ll see your HP-41s and HP-48s and raise you an HP-34C that will be 40 years old this coming December.” But @flga kind of beat me to it with his great HP-35. Anyway, here’s a video I shot this evening of my HP-34C running a program, using its built-in numerical integration function, to compute a Bessel function of the first kind of order 2, for an argument of 6.5. The HP-34C was the first calculator to have numerical integration and root finding built-in, and it had a lot of other functions for an inexpensive calculator (compared to other HP calculators). It had so many functions on the keyboard that it was one of the few HP calculators to have *three* shift keys: f, g, and h. Of course, the red LED display that goes nuts while a program is running is wonderfully retro.
After having coveted HP-35, HP-65, and HP-67 calculators for 8 years since the introduction of the HP-35, I was able to buy an HP-34C in the fall of 1980 while I was an undergraduate. That first one failed within a few months, the only professional HP product I’ve ever had fail (I’m not talking about the later consumer HP PCs and cheap printers). So the HP-34C I have to this day, shown in the video, is the warranty replacement that came in early 1981. The beginning of the serial number is 2051S, which according to the scheme used for all HP products at that time, means it was manufactured during the 51st week of 1980 (1960 + 20), in Singapore (S = Singapore, A = USA, etc).
The original NiCd battery pack long ago gave up the ghost, so several years ago I bought two after-market packs, in order to fire up this calculator once a year or so for nostalgia’s sake.
This little, nearly 40-year-old machine took 3 minutes 42 seconds to compute that Bessel function (I cut the video down to 45 seconds). By the choice of display setting, I told the calculator that the integrand was accurate to only the nearest 0.0001. In actuality, the integrand function is exact (within the precision of the calculator), but the more precise you say the integrand is, the longer the calculator will spend computing the integral. At the end of the video, you see the result and the upper bound for the uncertainty of the result (the integration function returns both, in the x and y stack registers, respectively). I momentarily display the full mantissa of both.
The calculator got the result correct to 6 significant digits, giving -0.30743030… compared to the true -0.30743039…
I’ve realized that in the program, I forgot to scale the computed upper bound of the uncertainty by the same factor of 1/pi that multiplies the result of the integral, so the shown 0.00015708… in the video should really be 0.000050000… which is still far bigger than the difference between the calculator’s result for the Bessel function and the true value.
I meant an HP42 & HP48. Someone needs to take me out of the typing pool.
@john-putnam The two main differences are the the HP-42S was a traditional RPN calculator with keystroke programming, with no expansion or I/O capability (other than IR printing), and the HP-48 series offered the RPL LISP-like programming (that was introduced with the HP-28 series) with an “infinite” stack and had card slots and wired, serial I/O.
I have an HP-50, not used a lot.
I have two HP48’s, one TDS and one SMI card.
I have a HP41GX, had to fix it, is stored away and
still works, it was a gift.
I have a HP15c really used a lot.
I had an HP11c (stolen)
I have a newer HP35
and a newer HP33I guess I should have purchased some HP stock but never did. 🙂
I am still in deep with HP15 and a handful of 41s.
the best part is the iPhone i41cx+ app. I still write stuff for it. The HP15 iPhone app by HP is a front line app when my original is out of reach.
Q: does anyone recall a COGO app for 41 called KO?
Many a field crew, laid out many a project and was hook line and sinker to that full featured cogo program. Particularly since ray-outs for everything was hard copy from the office. It saved my ass on test day. (1991).
I have KO running on i41CX and it??s wonderful. (Available to those familiar with KO)
I??m curious if anybody else had used that program.
And I had 2 41s with battery terminal corrosion. There are replacement parts for that since it was a killer to 1/2 of all 41s.
I have repaired those 41s. Still the best that ever was.
I just inherited a couple of new HPs from a friend and former employer whom passed away in March. A 48GX with TDS Cogo card and a 41CX with Survey I, Navigation, Aviation & memory modules. The 41 has a cracked screen but still fires up.
It is kind of fitting that his ex-wife sent them to me since he is the one who lost my 48 years ago. And no, this is not the same one.
I think these should last me. I can’t imagine using anything other than a RPN.
My HP48GX from college gave up the ghost about 4 years ago. It was about 4 months after an engineer colleague of mine gave he his 48GX because he didn’t use it anymore. That was close!
I should look around and figure out how to get my original one repaired, because I suspect it to be 20+ years before I retire.
The 48’s usually aren’t really dead. Push down on the bezel above the screen then try to power on with fresh batteries. If that fires it back up take 2 nickles and put them where you pushed then double wrap a strong rubber band around them and the calculator and it will last a good while longer. I have 3 48GX’s that I’ve stopped trying to MacGyver and just use the app on my phone now but the 48 and RPN changed my life in college having only known TI’s before that.
Never used any desktop calculator other than an HP. Long live RPN!
I had an ongoing battle with my roommate in college regarding TI versus HP.
A bit of trivia…HP was the source of the original GPS design that became Trimble. Charlie Trimble and others left HP to start a new company when HP decided to not pursue GPS. At least that is how I remember the story that was told to me long ago.
And who remembers HP EDM’s and total stations. The 3805 (with T2) and 3810 (total station) were the first EDM’s I used when I started in surveying in 1980.
I used a 3810 as an EDM on my first job out of school. We were a fill in crew from the office and all of our total stations were out of the office (T2000s & T2002s). We used it as an EDM for a T-2. Kind of kludgy but it worked.
only a kludge in hindsight. There was a time when having one was a competitive edge. And glad to have it.
I’m sure they were great at the time. Hell it beat pulling chain for the job we used it on. I feel very fortunate that I came into the profession at the end of chaining. Besides school, I only had to pull chain for layout within 50 feet of the gun.
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