HP reverse polish notation scientific calculator

me | today | me

[KC Burke]

I have noticed that a couple of their new calculators have switchable RPN addressablity. I beleive one of the 12c business versions and one of their scientific versions. I think some of their current graphing calculators are RPN but I do agree that their build quality for the new units isn’t what it was for the old ones.

I have an old 12c algebraic which I am used to. I have dropped it from my shirt pocket into water (I won’t say where or how I rinsed it off) and it still works after 18 years. Will use it till it dies.

[starlifter]

That is indeed extremely manly. It goes well with this:

[mamelukesabre]

I think the reason for the switchable RPN is twofold:

Firstly...they are trying to attract the customer base that doesn’t comprehend RPN

Secondly...as I understand it, the REAL purpose of RPN back in the beginning was NOT to help out engineers and others that can do long tedious calcs faster with RPN. The real purpose was that the memory and the CPU were used more efficiently with a system designed around RPN. Nowdays, there’s no reason to worry about conserving computing power and there’s no such thing as a scientific calculator designed around RPN. If the calculator has RPN at all, it’s actually an RPN emulator that hogs more computing resources than if the RPN is switched off.

Computing power is all a moot point when it comes to a handheld calculator.

For instance...the HP 50G that I just bought for $60 has a 203 megahertz 32 bit CPU that is factory underclocked(presumably because there’s no cooling system in a pocket calculator and the power supply is limited to 4 AAA batteries) to 75 MHz and 512 Kilobytes of RAM. And it will accept a 2gigabyte SD flash memory card.

Compare that to my first IBM compatible computer that came with a 4 point something megahertz 8088 CPU(8 bit, iirc) and I forget how much RAM but I think it was 128K. The hard drive was under 20 megabytes...I wanna say 16MB but I can’t remember for sure.

This is my understanding, I’m sure someone will correct me if I got something wrong.

[huskerjim]

I bought my HP11C in 1983. It still works great. I just don’t use it for programming any more. Other computers are much better. I love teh HP11C.

[huskerjim]

I bought my HP11C in 1983. It still works great. I just don't use it for programming any more. Other computers are much better. I love the HP11C.

[mamelukesabre]

Well, I figured out the secret shortcut for “swap” and “review”. But I still havn’t figured out where the function is that converts a decimal into a quotient. I’m afraid they left it out.

Boy! This thing is really slow. One very deadly flaw of the 50G is that I can tap the buttons faster than the thing can register them. That’s not good.

[saundby]

I’ve been looking around to see if I an pick a 50g up for mysself at anything near the price you got. No luck so far.

On the keyboard, I’d been warned the default key response time is too slow. The fix is to set the KEYTIME variable to something like 1/3 to 1/4 the default time, e.g.:

400 ->KEYTIME (when in RPN)

You can write it as a short program and set it to run at startup (by naming it STARTUP, I’m told.) I understand that there’s an enhancement request in at HP to make the default time shorter, and user settable without resorting to a program.

I’m not familiar with the fraction functions, I’m afraid.

[mamelukesabre]

I guess I need you to walk me through this.

I typed in:

(alpha)(alpha) KEYTIME(alpha) (orange shift) (arrow) 400 (enter)

Then I typed:

’ (alpha)(alpha)STARTUP(alpha)(space)(STO)

Now there is a variable named “STARTUP” with the value “KEYTIME(arrow)400’

Turn off the calculator. start up the calculator.

Still no good. I can still tap the buttons too fast for them to register.

Then I trid this:

(orange shift)<<>> (orange shift)(CAT) (down scroll to “keytime->”) (ok)400(enter)’(alpha)(alpha)STARTUP(space) (STO)

still no good.

Then I tried:

(orange shift) <<>> 400(orange shift) CAT (scroll down) (keytime->) (ok)(space)(enter) ‘STARTUP’ (STO)

Then turn off HPm, then turn on HP.

Still no good.

[saundby]

If I had a 50g I’d write it down keystroke by keystroke. I just remembered having a coworker warn me about the problem when I was thinking of picking one up some time ago.

I found some info online, though:

Near the bottom of this document (item 9), it describes things:
http://www.student.montefiore.ulg.ac.be/~merciadri/docs/hp50g/hp50g.pdf

This talks about keystrokes when entering the commands some:
http://home.gwu.edu/~mvolz/hpcalc/

There’s a message in this thread that gives details, too:
http://www.physicsforums.com/showthread.php?t=157969

If I don’t turn up an HP-50g at something <$80 soon, I’ll probably pick up a 35s. I know it doesn’t have everything the 50g does, or even my HP-41CV/CX’s, but I’ve heard it’s as close as you can get to the “classic” HPs these days, and they go for ~$40.

[mamelukesabre]

Awesome dude.

That first link is crap. Their instructions DO NOT WORK.

The second link is the correct method. It works. And it appears to be permanent. I thought it would reset itself when you turn off the calculator, but it does not.

So apparently, who ever told you to store the program in “startup” is incorrect. This is totally not necessary. Perhaps if you pull out the batteries, THEN the calculator will reset itself. That I dont’ know. I didn’t try it.

The important thing to remember is to delete the automatic spaces inserted when you use the (orange shift) (zero key) sequence...makes you wonder what the purpose of those spaces is anyway?

Using the method in your second link, I thought maybe that series of keystrokes was merely a shortcut method of defining a variable named “keytime” and assigning it a value of 500. WRONG. After doing it i searched low and high for a new variable named “keytime”. None to be found anywhere in calculator. Creating a variable named “keytime” obviously does NOT work.

After you told me you are having trouble finding one of these little guys for $60.99 or even under 80bucks, I’m sitting here wishing there had been a bunch of them at best buy and I bought them all up. They only had one left though. Maybe that’s why it was so cheap...marked down from $139.99

I’m finding another annoyance with the 50G. The “purge” command is in a very unfortunate and inappropriate place...unless there’s another super secret shortcut I don’t know about. I’m gonna scour those links you gave me. I already searched the CD that came with it. Nothing.

And my eyes seem to be unwilling to adjust to the 50G’s “divided by” button. They really did screw up when they layed out the keys on the 50G. It’s obvious the enter button was originally meant to be in the same old HP standard location. But then they moved it to the “+” key and then shifted all the operator keys(+,-,x,*,/) up one spot. Doing so pushed the “/” key up into the smaller buttons. My eyes can’t find it. they insist on looking for a large button the same size as all the other operators.

The other thing that I can’t adjust to is the spacing between the buttons. The older HPs had more space between the buttons, and the buttons felt like they stuck out higher. That made it easier to find the buttons quickly(by feel) without needing to focus your eyes directly on each button as you tapped each one.

And finally, the color yellow was a really dumb idea. ON the 50G, the alphabet is printed in dull yellow. I CANNOT SEE IT. Really aggravating.