Recently, much to my joy, my son got to that special level of mathematics that require a calculator a bit more powerful than Window’s calc.exe. I knew I wanted the kids to learn RPN, primarily as a way to deconstruct problems and segment them. I found that using RPN in college helped me see calculus equations a bit differently, and as such, I did a much better job and avoiding sign inversion (my kids biggest problem). So since I had a captured audience, I started with the RPN indoctrination before a Casio or TI could object. Before there could be the chance for suggestions on the matter, I went for my old hp48gx from college. This did not go over well. After a bit of reflection on the matter, I decided that the hp48gx was a bit too much for his current workload, so I started looking for some smaller options

Here’s some of what I stumbled on:

  1. Android Free42 - By far, one of the best hpCalc simulators I have found to date. The software is all open sourced, and doesn’t use any pirated hp ROMs. I was very impressed with this effort and pleased to see it is receiving active development, and seems to have a huge following. Best of all, the hp42s is the perfect size to simulate on a smart-phone. Although the hp48sx emulators/simulators seem solid enough, they are just a bit too busy for my tastes. I immediately installed this on all the kids smart-phones. Of all the options, this was the best fit, except for the fact that no algebra teacher would ever allow a kid to take a test with a smart-phone. That aside, this product is very solid. Nice features include:
    • Program Import / Export - Fantastic feature. I can write programs on my smart-phone then import them on the kids.
    • Program Listing / Printing - Good for sharing programs with others… like you guys.
    • Program ‘Compiler’ in Perl - Haven’t dabbled with it much, but seems solid enough.
  2. Used HP 42s - After falling in love with the Free42 project, I figured I just get him a throwback HP 42s. MISTAKE. Although they retailed for $100 back in the late 80s, these things go for $500 today. INSANE. OK, I like the 42s, but not that much.
  3. HP Prime Calculator - If the 48gx didn’t work for them, the Prime wouldn’t either, but since I was on the calc page, I looked it up. This one seems to be their flagship calculator and and has a pretty big following. I just about bought one for myself, purely on calculator nostalgia, but noticed the HP Store was sold-out (panic). I was not pleased, and this raised some alarms. Is HP leaving the calculator market? Are they discontinuing their flagship? I did see some on Amazon, but wasn’t going to shell out that kind of money.
  4. HP 50g - Yes, I had to get one. Partly for nostalgia, and partly from the panic of seeing the HP Prime sold-out. I figure, if I force my kids into the RPN mindset, I better make sure they have a calculator for Calculus. So my 50g is my backup plan. No complaints. Looks and feels a lot like my ‘48gx’ with some impressive ‘CAS’ capabilities that the 48gx did, but reluctantly.
  5. HP 35s (WINNER) - This was the right form factor, handled complex numbers, equations, programmable, and most other stuff I thought the kids might need for the next few years. Although this is a newer calculator than the 42s, it is not nearly as featured, but since I was looking for a smaller option, it was perfect for my needs. Few likes and dislikes:
    • Likes:
      • 800 Indirect Variables - At first I didn’t dabble with the indirect variables, but as I began to write more programs on it, they became very useful. I generally leave these variables to programs and I don’t have to worry about clobbering them. I also consider I and J as volatile and assume that any program may clobber them.
      • User Flag Annunciator - This allows me to work around some of the dislikes I have. I can light a user flag annunciator ant that lets me know certain conditions happened in my program, and how to remedy it.
      • Programmable - This, above all others, fixes any shortfall. Almost anything the calculator “can’t do” can be fixed with the right program. Almost…
      • Complex Number Support - This solves so many problems and am grateful for it’s inclusion in this model, though it is a bit kludgey.
      • Fraction Display - I could care less, but my son loves this feature above all others. I include it for his sake.
      • Form Factor - Frankly, this is why I got it. It looks like a standard puny Casio. No real indication of the power within.
      • Full HP Support - Full set of manuals, full set of features, full warranty. Everything a father could ask for.
    • Dislikes:
      • Single Letter Program Names - I thought this would be a nightmare, but my solution was simple. Write a program to display what the other programs are. I call this program H for [H]elp. It requires a bit of extra work to add a entry in the Help program whenever I write a new one, but this is simple enough.
      • No Export - Would have been nice to have a USB cable. I’ve written about 5-6 programs and would have liked an export capability, but as it stands, I’ll have to transcribe. Not a really big deal, but an annoyance.
      • Kludgey Complex Support - Complex math is only supported on a few functions. X^Y supports complex but X^2 doesn’t. Silly really. OK, so I just have to do X^(1/2) then. Ohh well.
      • No Continue On Error - Previous HP calcs have Overflow Halt and Overflow Status flags, but on previous ones clearing them had a wonderful side effect. Previous generations would allow you to Continue On Error if Overflow Halt was cleared. This means you could trap errors and recover in your programs. Try as I might, I could not get the HP 35s to do this. Overflow is only for Overflow, nothing else. What I did settle upon was to make programs Restartable. Before I do operations that could trigger an error, I set a flag (and clear it after). If the error halts the program, I restart it and can tell what error happened and then jump to some trap code. Kludgey but workable.

All in all, I love the HP nostalgia and have had a lot of fun recalling all my RPL mad skills. Even went through a few program listings with the kids. They were patient, but not really that interested. Ohh well. I still have some toys to fool around with.