Re: Poll - How long did it take you to gel with RPN/RPL? Message #9 Posted by James M. Prange on 21 Mar 2003, 5:42 a.m., in response to message #1 by Jeremy
With RPL, maybe a minute? Although of course I wasn't competent to write
a program in that time. But I knew, deep down, as soon I realized how
the display model worked, that a 28C was a "must have" calculator. By
the time that I had nearly convinced myself that I really "needed" it
and might be able to afford it, even though it didn't have nearly as
much memory as my Sharp EL-5520 or it's I/O (well the 28C does have
output, but no input) and it was pretty expensive for a calculator, and
went back to the store for another look, it had been replaced by the
28S. I was writing simple programs (well, at least copying them from the
Owner's Manual, understanding how and why they worked, and writing my
own slight variations) the first evening that I owned a 28S. So much
more straightforward than writing a BASIC program for the Sharp or
recording an algebraic entry keystroke program for my little Radio Shack
calculator. How could anyone ever go back to those?
After experiencing RPL, I could never go back to algebraic entry (or
writing a BASIC program) for anything that I could justify writing a
program for, although I do keep batteries in the Sharp and various cheap
calculators that I have. The Sharp mostly for old time's sake (and it's
easy on batteries when not being used), and the cheap ones because they
fit in a shirt pocket, although I have to think about how they work when
I use them. Actually, my old Lloyd's from around 1980 and my Radio Shack
from the late '80s still work on the original batteries; amazing, even
though they're rarely used.
I'd have to say that it was more the case that algebraic entry never
really "gelled" with me. It never did seem "natural" to press an
operation key like + before entering the next argument; how can you add
two numbers when you've only keyed one of them in? I kept pressing the =
key after keying in the first number and then keying in the next number
which replaced the first number and left me very frustrated, so I
considered calculators to be a pain in the neck to use, although they
were useful enough to be worth a little pain. RPN (or RPL) entry seems
natural for me. I did buy a TI SR-51A when they came out with that
(about 1975) with it's heavily advertised algebraic entry, but I found
it to be rather a disappointment (although quite useful), and stopped
rebuilding the battery pack when I got a cheaper scientific calculator.
With RPL, calculators are easy to use and program (and fun to play
with).
But of course, I had started out with pencil and paper and slide rule,
which pretty much force one to do numerical calculations in an RPN
manner.
And at various times I'd used adding machines. One of them in the front
office at work even did multiplication, but I don't remember whether it
did division as well. It didn't even need batteries or have to be
plugged in, you just cranked the handle to get the answer. I wish I
could've seen it with the covers removed. I hope that it didn't get
trashed and that someone treasures it; it was a very impressive machine
and I'd love to have it for my own.
The first electronic digital calculator that I ever got my fingers on
was a Canon which needed to be plugged in and used Nixie tubes for
display. Not programmable of course. It just did the basic arithmetic +,
-, X, and /; nothing so sophisticated as square root. That was around
1971, and it was certainly a wondrous device. I pretty quickly developed
a routine for finding square roots far more accurately than a slide rule
could, but as a practical matter, for "real world" problems our input
data was approximate (I doubt that it was accurate to three significant
digits) and slide rules were much faster and more convenient. But the
calculator was fun to play with. I found that it had a problem with
dividing by zero. When it did a calculation, the various cathodes in the
Nixie tubes flashed on and off while it was working on it. When I tried
dividing by zero just to see what it would "think" about that, the
cathodes in the tubes near the the right side began flashing, and the
flashing moved leftward until all of the cathodes in all of the tubes
were rapidly flashing. The only way that I found to get it to quit was
to turn it off. I left it going bonkers once for the owner (one of my
shipmates, who I guess had spent about a month's pay on it) to see when
he wandered into the shop. He looked as if he were about to have a heart
attack, but he more or less calmed down after I turned it off and back
on, tried it out, and found that it seemed to work perfectly. I never
did tell him that I had any idea of what had caused the problem; I
wonder whether he ever discovered how to make it do that. He's certainly
smart enough to know that it doesn't make any sense to divide by zero,
but I'm not so sure that he'd be curious enough to try it on a
calculator just to see what would happen or careless enough to do it by
accident.
Sure brings back a lot of memories.
Regards, James
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