Originally posted by Suzianne
Well, the last three sound about right, even though I've seen little evidence of the last one. I'm surprised you managed to spell the first one right.
Ain't spelchekers great? Suz, total off topic: you asked me why the reverse polish calculator was such a big deal, remember? A guy and his wife who live near where I work, I am recording their band, getting paid evenπ anyway, I saw he had a Hewlett Packard calculator I had wanted for a long time, a reverse polish model, the HP11C. I have the HP12C which looks just like the 11 but is used for financial calculations, how much do I owe after 23 payments out of a 30 payment schedule and so forth.
For engineering work it is not so great so I wanted the 11, and Jon had one and gave it to me.
I downloaded the manual, still around on the net, even though the 11 and 12 are from around 1985.
The manual explains RPN really well, which surprised me.
One of the calculations I used to make was figuring out where to put the frets on a guitar fretboard. One a regular calculator with number storage you need to do this:
Find the 12th root of 2, which is 1.059 (that is the fundamental number used to figure out frequencies of notes, then invert and you get 0.9438 and change and this number can help in figuring out just where frets go on a guitar (they get slightly closer together as the notes get higher but at the first octave, the number is exactly half the distance).
So with a normal calculator, you first get to that .9438 thing, hit STO A (puts that number in memory location A) and then you enter the max size of the fretboard, in this case for simplicity, 1000 mm or one meter.
Using that calculator, you go RCL A times 1000, and you get 943.8 mm which is where fret # 1 goes. Then you again go RCL A times that 943 and you get 890 mm and for fret 3, 890 times RCL A, get the picture? By the time you get to the 12th fret, you have done 36 button pushes. At the 12th fret it is exactly at 500 mm.
But in RPN, you do the math to get 0.9438 (inverse of the 12th root of 2) and you hit Enter, enter, enter. That puts that number at the top of the "Stack", which is just 4 memory locations arranged where hitting enter puts a number in the first lowest level of the stack, hitting enter again reproduces the same number one stack higher and so forth till all 4 stacks have that number in it.
So that takes 3 button pushes.
Then you just put in 1000, now just hit the X button (multiplication) and you get that first fret number 943.8 mm then just keep hitting X and the next number appears, X again and the third and so forth, so by the time you get to the 12th fret, you only have pushed 12 button pushes plus the 3 enters, so 15 keystrokes to do what normal calculators takes over twice the keystrokes. You get the answer as soon as you hit the next X and no futzing around with recalls and such.
That is just one small example of how RPN is superior to regular parenthesis based arithmetic. When you were taught arithmetic in grade school you wrote down the first number, put the next number below it and put the operation next to the second number and did the math. That is exactly how RPN works, no parenthesis needed for long chained math like this: (3X8)+(5-98)/(8X6)+(5-67). RPN handles all the internal details of doing that math without having to resort to all those parentheses, and it gets even more complex if you have multiple embedded stuff like ((8x7)+(3/4))/ (((7+3)x(6+4))X (4-8)/(3+8)) RPN eliminates the need for all that faldarah of nested parentheses.
I know this belongs somewhere else but I know this is a recent post you made so spilling it all hereπ