Thanks for the tip on the HP32 calculator!

Yeah, but you can no longer buy an RPN calculator that will comfortabley fit in your pocket (except used, for big $). I really miss the HP42S that I lost years ago. It was perfect for my needs and nobody makes one like it now.

Aaron, Hang on to that HP32! I'm jealous.

-Greg

Is that HP 32 reverse polish notation. I have used a RPN HP since about

Check with Radio Shack. They sell "fractions" capable calculators for around $15.

HP is coming out with a replacement for the 32SII, the HP 33S. It doesn't seem to be widely available but some people have been able to buy them. There's some discussion of this new model over on comp.sys.hp48.

Hey, thanks for the tip! I'll keep my eyes out for it.

-G

Yes, the HP32S is RPN. I purchased a HP41C in 1981 and have been using that daily as I was more still more comfortable with it than the HP32. After finding the fraction feature on the 32S, I think it will be seeing more use. And my HP 11C stays by my bedstand for those back of the envelope kind of problems that keep me up at night ;-)

Also, there are several HP RPN emulators for Palms and Windows CE devices. I've got an HP41CX emulator on my Palm, but the only problem is that it lacks the wonderful feel of the real HP keyboards.

I'll have to look into the HP33S. Wonder if I can still sell the

See

-ask

I know what you mean - have a 28C clamshell and a TI 81 for the shop . The 28 is for the office.

At work I use a software version of an HP on my PDA.

Martin

Yes. At one time years ago they were in the clearance bin at Wal-Mart for $10. Should have bought more. Hands off mine!

You may be able to buy it direct from HP's website.

Greg sez:

Hey! No problem. I was never "comfortable" with RPN all along. IMO, RPN was developed (HP probably) to accommodate the shortcomings of early microprocessors. It takes a helluva lot more processing power to enter equations "the natural way". Again, and IMO, those that became "comfortable" with RPN were deluding themselves into thinking they were some sort of math geniuses for doing so. On the other hand -- I assume anyone that could be "comfortable" with the awkward back and forth motion of a slide rule might not agree. Now, before anyone jumps on me for that statement - I have several slide rules and know how to use them. Expertise with a slide rule did not dupe me into learning RPN - I chose to wait until AE came along.

Bob Swinney

I think it was developed by engineers with programming experience who thought it was more efficient. It is. Forth and Postscript both are stack-based computer languages. Languages such as C generally re-arrange things at compile time so that they can execute similarly at run time. That re-arrangement is somewhat non-trivial (recursion) but that's not what AE calculators do- they just store intermediate results and pending operators.

Eg. 2 * sin(43°) + 0.5

RPN AE

--- --

• sin .5 +
• 0.5 =

Eg. 4 * ( 5 + 7)

RPN AE

--- --

• (

• + 7 ) =

Nah, the stack on early HP calculators was 4 levels. If you want to use "the natural way", the calc chip needs to store one intermediate result for each level of paren or implied paren, and the operator. So it is just a tiny bit more RAM (to hold the operators) and probably a few more intermediate results (depending on how many levels of paren the calculator can handle).

Entering things from the "inside out" rather than from "left to right" always seemed easier to me, fewer keystrokes and less chance of making an error. The results you need for the next step often seem to right there from the last step. The fact that people would avoid borrowing your calculator was just a bonus. ;-)

Too bad no manufacturer (AFAIK) has offered RPN as a simply set

Best regards, Spehro Pefhany

I think the newer HP calculators can be operated in either mode.

Jim

================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================

HP48 is the latest I have, and it's RPN only, but I've got a (n even older?) clamshell HP financial calculator HP19B that is AE only.

Best regards, Spehro Pefhany

I think it is more efficient for many calculations, if you can keep track of what's on the stack. It's also fun when some engineer borrows it at a meeting and can't figure out how to multiply two numbers.

comfortabley

HP48 is the latest I have, and it's RPN only, but I've got a (n even

See, HP finally realized that basically non-math types wouldn't want to mess with all that complexity so they put in AE. But we know the real reason don't we.

Bob Swinney

My point exactly. The engineer is unable to re-learn his math under pressure (and he is math trained). So, the ordinary mortal is in for a ton of confusion if he tries to figure out RPN. True, it makes lots of folks break arms patting themselves on their backs over how smart they are - but - the fact remains, RPN was introduced because of electronic limitations of the time. Sphero explained it very well when he said that AE takes more interim memory.

Bob Sw> > Greg sez:

In my opinion, the HP-27 was the best pocket calculator of its day -- perhaps the best of all time. It could do algebraic, statistical, and financial routines -- all hard wired. Yes, it had a LED display, and needed to be recharged often, but it could do it all. Mine won't any more, because the key contacts have been worn out. I would pay dearly for the same capabilities in a similar wonder machine with LCD display.