[noise] Re: Sliderules, Logs, and Prodigies
Peter Trei wrote:
When I was in high school, slide rules and log tables were standard equipment - calculators started to come in towards the end. There was a *lot* of controversy over their use in exams, and in homework ('show your working...'). At one point, you could use a calculator, but only if you noted the fact (and model) on your exam paper.
If I remember my history right, the order that math was done often depended on the model of calculator it was done on. I remember being warned as late as 1991 how some calculators may still still add before they multiply, and to use those parenthesis for good measure, just to be safe.
I still treasure one of the heirlooms from my grandfather - a 12 inch bamboo rule, with his name carefully engraved in engineering lettering ( which he used during his 50+ years at Ma Bell).
I know where there used to be a basic model slide rule that spans about 10 feet, it was mounted on the wall of the math room where I spent junior high. My dad actually taught me basic arithemetic on it. (Ironically, on the opposite wall were the computers, an Apple IIe, a Commodore 64, two TI99/4a's and about 4 Tandy 1000/tx's, this did all take place before 1989) Sean Roach
(Someone renamed my thread with the "[noise]" prefix. I have removed this stupid prefix. Anything people think really is just noise should not even be posted. I favor picking descriptive thread names, and try to do it whenever I can, rather than cluttering up thread names with cutesy labels.) At 2:44 PM -0800 11/5/96, Sean Roach wrote:
If I remember my history right, the order that math was done often depended on the model of calculator it was done on. I remember being warned as late as 1991 how some calculators may still still add before they multiply, and to use those parenthesis for good measure, just to be safe.
Well, it ain't _history_ only--it's also current. Some of us use RPN (Reverse Polish Notation) calculators exclusively. (Even my screen calculator I use on my Mac is an RPN one.) The main split is between RPN and algebraic. Algebraic calculators use parentheses to establish operator precedence and to alter precedence, RPN calculators do not. (Yes, purists will note, advanced RPN calculators have options for parentheses, brackets, and other similar things, and can even process algebraically. But not in the basic models, and the RPN computational model, being stack-based, does not require them.) To see how RPN works, visit any electronics store that carries Hewlett-Packard calculators, especially the advanced ones like the H-P 48, and read the first 5 pages of the instruction manual. It will all become clear to you. --Tim May "The government announcement is disastrous," said Jim Bidzos,.."We warned IBM that the National Security Agency would try to twist their technology." [NYT, 1996-10-02] We got computers, we're tapping phone lines, I know that that ain't allowed. ---------:---------:---------:---------:---------:---------:---------:---- Timothy C. May | Crypto Anarchy: encryption, digital money, tcmay@got.net 408-728-0152 | anonymous networks, digital pseudonyms, zero W.A.S.T.E.: Corralitos, CA | knowledge, reputations, information markets, Higher Power: 2^1,257,787-1 | black markets, collapse of governments. "National borders aren't even speed bumps on the information superhighway."
On Wed, 6 Nov 1996, Timothy C. May wrote:
At 2:44 PM -0800 11/5/96, Sean Roach wrote:
If I remember my history right, the order that math was done often depended on the model of calculator it was done on. I remember being warned as late as 1991 how some calculators may still still add before they multiply, and to use those parenthesis for good measure, just to be safe.
Well, it ain't _history_ only--it's also current. Some of us use RPN (Reverse Polish Notation) calculators exclusively. (Even my screen calculator I use on my Mac is an RPN one.)
Yes, many calculators still have the add/multiply error also. Most of the newer generation (the one which I wish I didn't have to be a part of) doesn't know what RPN is, much less how to use it. A friend of mine found his father's RPN HP (don't know which model) from college a week or two ago, and you'd never beleive how long it took me to convince him that "RPN" really does stand for "Reverse Polish Notation". As for slide rules, I think I'm the only person at my school who knows what a slide rule _is_, much less how to use one ;) --Deviant Insufficient facts always invite danger. -- Spock, "Space Seed", stardate 3141.9
On the topic of slide rules: I am looking for a "teacher's" slide rule. The 5 feet long model that used to hang off the blackboard. Any idea where to get one? I pay cash. -- Lucky Green <mailto:shamrock@netcom.com> PGP encrypted mail preferred Member JPFO. "America's Aggressive Civil Rights Organization"
The Deviant wrote:
On Wed, 6 Nov 1996, Timothy C. May wrote:
At 2:44 PM -0800 11/5/96, Sean Roach wrote:
If I remember my history right, the order that math was done often depended on the model of calculator it was done on. I remember being warned as late as 1991 how some calculators may still still add before they multiply, and to use those parenthesis for good measure, just to be safe.
Well, it ain't _history_ only--it's also current. Some of us use RPN (Reverse Polish Notation) calculators exclusively. (Even my screen calculator I use on my Mac is an RPN one.)
Yes, many calculators still have the add/multiply error also. Most of the newer generation (the one which I wish I didn't have to be a part of) doesn't know what RPN is, much less how to use it.
A friend of mine found his father's RPN HP (don't know which model) from college a week or two ago, and you'd never beleive how long it took me to convince him that "RPN" really does stand for "Reverse Polish Notation". As for slide rules, I think I'm the only person at my school who knows what a slide rule _is_, much less how to use one ;)
According to HP, the "Polish" part of the term comes from a Polish mathematician whose name (I can't spell it, and I don't have the .DOC) is pronounced phonetically: WOOCASHEVITZ. The "reverse" part apparently means the inventor specified the operation before the parameters, instead of how HP implemented it.
At 10:33 AM -0800 11/7/96, Dale Thorn wrote:
According to HP, the "Polish" part of the term comes from a Polish mathematician whose name (I can't spell it, and I don't have the .DOC) is pronounced phonetically: WOOCASHEVITZ. The "reverse" part apparently means the inventor specified the operation before the parameters, instead of how HP implemented it.
Lucaciewicz, as I recall. His notation was originally that one would add two numbers, a and b, as "+ a b." A modified form, adapted for stack machines, was to add two numbers with "a b +." Hence, _reverse_ Polish notation, but equally sound. This involves entering a, then pushing it onto the stack with an ENTER, then entering b, then hitting the "+" key to pop the stack and place the sum in the main (X) register. For people who claim that (6 + 7) * 5 is the "natural" way to do things, I point out to them that the way one does it one's head is to take 6 and 7 and add them then to multiply by 5. Or I show them 6 + 7 ----- 13 * 5 ----- 65 Then they see that RPN is actually the way we do things in our head. Or on paper. Computers do things with parentheses, we don't. By the way, Polish notation is how LISP evaluates expressions. E.g. (+ 6 7) or, for the full problem above, (* 5 (+ 6 7)) And for those of you are not LISP or Scheme fans, the language FORTH also uses Polish notation. RPN, in fact. --Tim May "The government announcement is disastrous," said Jim Bidzos,.."We warned IBM that the National Security Agency would try to twist their technology." [NYT, 1996-10-02] We got computers, we're tapping phone lines, I know that that ain't allowed. ---------:---------:---------:---------:---------:---------:---------:---- Timothy C. May | Crypto Anarchy: encryption, digital money, tcmay@got.net 408-728-0152 | anonymous networks, digital pseudonyms, zero W.A.S.T.E.: Corralitos, CA | knowledge, reputations, information markets, Higher Power: 2^1,257,787-1 | black markets, collapse of governments. "National borders aren't even speed bumps on the information superhighway."
Timothy C. May wrote:
At 10:33 AM -0800 11/7/96, Dale Thorn wrote:
According to HP, the "Polish" part of the term comes from a Polish mathematician whose name (I can't spell it, and I don't have the .DOC) is pronounced phonetically: WOOCASHEVITZ. The "reverse" part apparently means the inventor specified the operation before the parameters, instead of how HP implemented it.
Lucaciewicz, as I recall. His notation was originally that one would add two numbers, a and b, as "+ a b." A modified form, adapted for stack machines, was to add two numbers with "a b +." Hence, _reverse_ Polish notation, but equally sound.
This involves entering a, then pushing it onto the stack with an ENTER, then entering b, then hitting the "+" key to pop the stack and place the sum in the main (X) register.
For people who claim that (6 + 7) * 5 is the "natural" way to do things, I point out to them that the way one does it one's head is to take 6 and 7 and add them then to multiply by 5. Or I show them
6 + 7 ----- 13 * 5 ----- 65
Then they see that RPN is actually the way we do things in our head. Or on paper.
Computers do things with parentheses, we don't.
By the way, Polish notation is how LISP evaluates expressions. E.g.
(+ 6 7)
or, for the full problem above,
(* 5 (+ 6 7))
And for those of you are not LISP or Scheme fans, the language FORTH also uses Polish notation. RPN, in fact.
I think claiming RPN for Forth is pushing it a little far. Admittedly it is stack-based (well, two-stack-based), and everything an operator can operate on is to the left, but the provision of arbitrary stack manipulation, "compile" mode (triggered by the '[' operator, if my memory serves) and so on make it rather a different beast. Incidentally, PostScript is Forth in disguise. Cheers, Ben. -- Ben Laurie Phone: +44 (181) 994 6435 Email: ben@algroup.co.uk Freelance Consultant and Fax: +44 (181) 994 6472 Technical Director URL: http://www.algroup.co.uk/Apache-SSL A.L. Digital Ltd, Apache Group member (http://www.apache.org) London, England. Apache-SSL author
Ben Laurie wrote:
Timothy C. May wrote:
At 10:33 AM -0800 11/7/96, Dale Thorn wrote:
[snip]
And for those of you are not LISP or Scheme fans, the language FORTH also uses Polish notation. RPN, in fact.
I think claiming RPN for Forth is pushing it a little far. Admittedly it is stack-based (well, two-stack-based), and everything an operator can operate on is to the left, but the provision of arbitrary stack manipulation, "compile" mode (triggered by the '[' operator, if my memory serves) and so on make it rather a different beast.
FORTH has fallen out of favor for most PC users of the mid 1990's, but then again, so have computer languages as a whole, since few persons write software today as compared to the early 1980's. But if you were privy to the inside of certain computing environments in those early days, like hanging around the PPC (handheld) guys, many of whom were UNIX users, you could appreciate their interest in FORTH. For one, handheld languages (Basic for example on the HP-71) and early PC languages were pretty slow, and FORTH added a lot of speed, and more access to system internals, which has been supplanted largely nowadays by 'C'.
-----BEGIN PGP SIGNED MESSAGE----- In message <v03007803aea873ff3acc@[207.167.93.63]>, "Timothy C. May" writes:
Lucaciewicz, as I recall. His notation was originally that one would add two numbers, a and b, as "+ a b." A modified form, adapted for stack machines, was to add two numbers with "a b +." Hence, _reverse_ Polish notation, but equally sound.
He also did some work on multi-valued logic, IIRC.
And for those of you are not LISP or Scheme fans, the language FORTH also uses Polish notation. RPN, in fact.
Yep, FORTH uses it for everything, including IF statements! e.g. < IF ." The Second on stack is smaller than Top Of Stack" THEN Derek http://www.maths.tcd.ie/~dbell/key.asc <- my public key here -----BEGIN PGP SIGNATURE----- Version: 2.6.3ia Charset: noconv iQCVAgUBMoNsLFXdSMogwMcZAQFtyQP+JIYnLgw754fE2Ku69ubk+yQolODBe2su KnQUOehxhZK2PvV0DQt7qWeMaKbbdmA8gxWKDBakX/2zuKuiUWbEzz2d53tEKt7s QGBgxOyaBNeWQVSACb5/rbKVH34rL7qUCxMatq5shsiBfvoPndePMeS/5qFjmt39 AbKJz+EDbuc= =SkNM -----END PGP SIGNATURE-----
As a HP-35 buyer when they first appeared in '72, I sonn found it simple to explain RPN by using a basic rule of good composition: avoid passive voice. The "+" key is not, of course "plus" rather it is the active voice term "add" and such.. And all commands are "active voice" unlike a TI where some were... Of course, I soon found far too many people had no grasp of active vs. passive voice........ -- A host is a host from coast to coast.................wb8foz@nrk.com & no one will talk to a host that's close........[v].(301) 56-LINUX Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433
At 8:19 PM -0500 11/8/96, David Lesher / hated by RBOC's in 5 states wrote:
As a HP-35 buyer when they first appeared in '72, I sonn found it simple to explain RPN by using a basic rule of good composition: avoid passive voice.
The "+" key is not, of course "plus" rather it is the active voice term "add" and such.. And all commands are "active voice" unlike a TI where some were...
Of course, I soon found far too many people had no grasp of active vs. passive voice........
Agreed. I think I adapted to RPN so quickly (less than 30 minutes at the university bookstore, which had H-P 35s on display) because of this. The problem "((5 + 7) * 4) / 3)" is easily understood as: 5 enter 7 add 4 multiply 3 divide Once one groks RPN, it clearly is a speed win over entering parentheses and that stuff. For any of you who are doubters, RPN usually produces far fewer errors in identical calculations than Algebraic produces (the user errors, not the hardware). I found RPN ideal for exploratory calculations, where the stack orientation was just so "natural." This is not RPNpunks, but it seems that many of the younger subscribers here really have not been exposed to RPN calculators. It's really worth the $40 or so to buy the cheapest H-P calculator that has RPN. (Be careful--not all H-P calculators are RPN these days. They bowed to market pressure several years ago and introduced algebraic entry on their low-end models.) --Tim May "The government announcement is disastrous," said Jim Bidzos,.."We warned IBM that the National Security Agency would try to twist their technology." [NYT, 1996-10-02] We got computers, we're tapping phone lines, I know that that ain't allowed. ---------:---------:---------:---------:---------:---------:---------:---- Timothy C. May | Crypto Anarchy: encryption, digital money, tcmay@got.net 408-728-0152 | anonymous networks, digital pseudonyms, zero W.A.S.T.E.: Corralitos, CA | knowledge, reputations, information markets, Higher Power: 2^1,257,787-1 | black markets, collapse of governments. "National borders aren't even speed bumps on the information superhighway."
Timothy C. May wrote:
I found RPN ideal for exploratory calculations, where the stack orientation was just so "natural."
This is not RPNpunks, but it seems that many of the younger subscribers here really have not been exposed to RPN calculators. It's really worth the $40 or so to buy the cheapest H-P calculator that has RPN.
I also used RPN calculators 10 years ago, in high school, in Russia. Still miss them. Which model (for no more than $40 or so) is the best around here? Sorry if this question has already been answered here, nowadays it is pretty tough list to read. thanks - Igor.
Igor Chudov @ home wrote:
Timothy C. May wrote:
I found RPN ideal for exploratory calculations, where the stack orientation was just so "natural." This is not RPNpunks, but it seems that many of the younger subscribers here really have not been exposed to RPN calculators. It's really worth the $40 or so to buy the cheapest H-P calculator that has RPN.
I also used RPN calculators 10 years ago, in high school, in Russia. Still miss them. Which model (for no more than $40 or so) is the best around here?
Don't waste the $40. Nowadays you can get an HP48G (without the ports) for $85-$90.
From: ichudov@algebra.com (Igor Chudov @ home):
I also used RPN calculators 10 years ago, in high school, in Russia. Still miss them. Which model (for no more than $40 or so) is the best around here?
Sorry if this question has already been answered here, nowadays it is pretty tough list to read.
I recommend the GNU emacs calculator. While not quite as portable as some of the HP calculators, it is free, and is definitely the best calculator I have ever seen, period.
participants (10)
-
Ben Laurie -
Dale Thorn -
David Lesher / hated by RBOC's in 5 states -
Derek Bell -
ichudov＠algebra.com -
Lucky Green -
nobody＠cypherpunks.ca -
Sean Roach -
The Deviant -
Timothy C. May