Re: Please, I hope people do not complain...



#2

Luiz:

Not to worry. As a longtime Apple Macintosh user, I'm used to being alone in a sea of Windows users. It's the same story repeated time after time: Beta was superior to VHS, but VHS won. The Mac has always had a superior interface (in my opinion), but Windows won. RPN has many advantages over AOS, yet the latter won.

Why? It's not a question of product quality or merits; it's just marketing. There's little chance of reaching the masses of (usually) less-informed users and counter the effects of marketing. At least I've found it an impossible, quixotic task not worth trying for long.

-Ernie


#3

"The majority is the stupidity, knowledge was always with a few". Jean-Jaques Rousseau

Hehe, probabely there could be a better translation than mine,I suppose ;-)

Ciao.....Mike

#4

Ernie Malaga wrote:

> It's the same story repeated time after time: Beta was
superior to VHS, but VHS won. The Mac has always had a
superior interface (in my opinion), but Windows won. RPN
has many advantages over AOS, yet the latter won.
Why? It's not a question of product quality or merits;
it's just marketing.


That's not so clear cut, IMHO. Matter of fact, that's
what people on the losing side wish to believe, but that
doesn't make it necessarily true. It just may be that the
other people are right, yet one just won't consider the
possibility of being on the wrong side, out of all-too-human
stubbornness.

Just for instance, I worked at a video rental shop,
when Beta and VHS were 50-50 more or less, and it was our
experience that all Beta tapes would broke or become
defective long before the VHS ones. They might have a
slight edge in image quality, not noticeable at all in your
typical TV set, but they definitely were much less
physically reliable and VHS ones lasted much longer and
survived much more use and abuse.

As for the Macs vs. Windows, my humble experience
was that the Mac wouldn't let me do so simple a thing as
extracting a floppy disk when I needed to, and Apple would
force me to create programs following strict guidelines,
whether I wanted or not. And besides, I had to pay extra
for the 'privilege' and end up with an underspecified
product. No, thanks. Monopolies are always bad and Apple
has theirs with the Macs. No way.

Finally, 'RPN has many advantages over AOS' needs some
heavy qualification. Undoubtely, 4-level stack RPN was
a marvel when compared to early TI calculators, such as
the SR-52, TI-58 or TI-59, where you felt cramped and
absolutely lost as to just where you are in the middle
of a many-parenthesis expression. I think most RPN fans
always have in mind those kind of calculators when they
think 'algebraic'.

But next to more advanced pocket computers and
calculators of the time, such as the many worthwhile SHARPs,
classical 4-level RPN just doesn't hold a candle. Not when
you can type and see your full algebraic equation all at
once on the display, written on the display as it is in
the book, with named variables if necessary, and can go
forth and back inserting, deleting or changing anything
before you even press ENTER. Then after the result has
been computed you can recall the whole expression to the
display again, to edit or recompute with different values.
And if you think it merits being considered a program,
just stick a line number in front of it, press ENTER, and
there you are.

Only sheer stubbornness can claim than 4-level RPN
is better than such a typical, modern algebraic system.
And of course, if you take on someone having such a SHARP
and try to proselitize with your 4-level RPN calculator,
he or she will merely think you're pathetic at best, and
nuts at worse. Of course, SHARP is just an example, the
same can be argued for the CALC mode of the 71B, which has
the added advantage of showing intermediate results and
is capable of backstepping a calculation one step at a time
(but has the serious disadvantages of a 21-character
display and no multicharacter names for variables).

RPL
machines has some of those features as well, but RPL
programs and expressions are always much more cryptic and
difficult to create and understand than the equivalent
algebraic expression, specially if you must reorder terms
and/or use stack operations. If anything goes wrong, it
will take much longer and more effort to locate the fault
than in the purely algebraic version. No wonder masses
tend to stay apart from such unnecessary complications.

By the way, don't take this as any sort of
'attack' on RPN. I was doing and proselitizing RPN before
some of you were even born, and I like it very much. But
that doesn't blind me as to its shortcomings and other
system's advantages, to the point of thinking everyone
else is wrong and marketing is to blame. People are never
fool, assuming that they are just shows who the real fool is,
and if a product succeeds and flourishes against
the competence, you can bet there's something to it
apart from marketing hype.

My 3 cents.


#5

Well, I can't say I agree totally with John, but:

1; VHS is more durable in a physical sense, yes. VHS is essentially the same cartridge design as the data tapes used on a P3 Orion. The cartridges differ somewhat (like being made out of plastics vs various metals)- but the durability of the design is there.

2; (going back to the original post) Fully half the people I know have non-pc laptops, and most of those are Macs. I'm not sure when or how it got perceived that mac was dead. But I've been hearing it about unix, mac, and sun for over a decade anddon't even listen anymore. 5% or 10% marketshare is not dead. It's just what people like carly perceive as not worth even trying to keep. One can build a very successful and strong business on a smaller market share. Ask Porsche. or Ducati. or Alpine.

3; I see some other uses and advantages to RPN and HP calculators in general. Mostly based on computer science and programming.(then again, the only time I turn on a non-programmable is if I need to know its basic setup to help someone with math.)
I'll agree that if *all* you want to do is basic math and chemistry, the $15-$20 Casio is really a nice machine. Or the 30s. (and the programming capabilities of anything short of a ti83 aren't worth complaining about. For the ti-83/98/92 typs machines it is absolutely ugly, though.)
RPN has uses, advantages, and a "reason to be learned" in computing. Anything more than perl and Visual Basic, at any rate.
I won't get into RPL per se, I don't use it in an advanced sense very much. It isn't any more difficult than TI "basic"- and works in "algebraic" mode to some extent- and is similar to some other computer languages.
Small memory footprint keystroke programming with lots of math is (as I'm sure ahs been mentioned before) a great way to improve/develop programming skills. keeping 300 lines of code straight on a 2 line display, fitting a decent set of statistics programs into 384 bytes, programming the decision structures needed for blackjack (with a decent UI) on something with the chip for chip computing power of a coffee machine, having an accessible and usable device to do machine code on- these are all things you won't get form the Sharp, the Casio, nor (in quality where it's not actual availability) TI basic.

and that's my couple pennies :)
-C

PS- no, I don't think any non programmable has, or ever will have, an adequate set of stats functions. programmability (and matrices & solver) seems to me to be a requirement there.

#6

As far as the RPN versus AOS debate goes, I don't think we do ourselves any favours by assuming stupidity on the part of AOS users. We need to address the very real problem of the constant requirement to move between the steadfastly algebraic world of mathematics and our "preferred" world of RPN/RPL. There's always going to be an implied translation and thus conflict.

I would like to ask if anyone here regularly commutes between these worlds, and would like to share their views. For my own part, I've started using a TI92 as well as my HP machines.

Thanks and best wishes, David


#7

David,

I agree with you. The notion of assumed stupidity you mentioned is a result of the simple exclusivity seen regarding the relationship between RPN, HP calcs and their users; this exclusivity (always a precursor to superiority) is now enhanced by the perceived rarity of the calculators themselves. I use both systems on a daily basis, and even use a slide rule on occasion. Doing such helps me to focus on mathematics, not transient ideas like entry logic.

Thank you,

Marc.

#8

RPN better than AOS? That is simply a matter of opinion. Some prefer one and others prefer the other. My like of RPN has nothing to do with it being superior over AOS. Both provide correct answers.

#9

Hi;

for those who lost the first part of the thread (that is resting in the Archives), the title "Please, I hope people do not complain..." is because I made a reference to TI calculators in an HP-Only (far from being a restriction; just a matter of selected subject) Forum. So, I decided to continue the conversation by e-mails rather t

#10

Hi;

for those who lost the first part of the thread (that is resting in the Archives), the title "Please, I hope people do not complain..." is because I made a reference to TI calculators in an HP-Only (far from being a restriction; just a matter of selected subject) Forum. So, I decided to continue the conversation by e-mails rather than by the Forum; that's the reason for the former apologies.

Some comments over these posts. I referred to RPN and AOS some months ago, in other thread, as, respectively, math solution procedures and math notation. I see the difference between both like this:

 13 + 28 = 41  (math notation)

1 (carry)
13
+28
---
41 (solution procedure)

There are ways to get to a solution by using both, descriptive solution and math notation. It's far well known that math notation is not the best way to "describe the way to get to the solution". When we have to deal with a math expression and find its solution (numeric result), each of us will find our own way to solve it. Many will have the same procedure, others will have particular, shorter or longer versions. The math expression (notation) itself will not need to be changed anyway.

By exclusively analyzing one of the right solution procedures, maybe it's possible to restore the original math expression. In some cases, this task will be annoying, hard and time consuming, when inefficient; if we are lucky enough to grab the best explained, full of references solution, it's easier to reach the original math expression.

I think this is the "beauty" of RPN/RPL programming: having access to the inner thoughts of the programmer. I'm not going to comment direct, keystroke procedures to solve a general or particular problem, because they are based on usage principles not specifically related to the text I wrote here; my focus IS programming.

There is always a programmer's "signature" hidden in an RPN/RPL program. We can also identify this signature in an AOS program, because in many situations, simply typing in the keys that are equivalent to the math expression will not do the job. I do not mean that this is always this way, but sometimes it is easier to write a program based in AOS logic; it can also be hard because of the same reasons.

I owned and programmed AOS calculators (TI57, 58, 59), also BASIC-style Casio handheld (I remember I firstly tried C in one Casio handheld that amazed me at the time I was in the University; 1986?). Depending on the knowledge and understanding of the programmer, RPN/RPL allow him to create his own path, to fully use the stack registers to get to the results or simply use x- and y-registers contents, to explore all possibilities in order to reduce program steps (memory space), among other possibilities. The same is valid in an AOS-based calculator, and the fact that I do not know how to use them deeply enough does not mean they do not have their inner, surprisingly secrets.
(A note: I know the stack registers will always be used in the moment a number is typed in, but many programmers barely use Z and T registers, meaning they did not have to OR didn't get too deep inside the calculator's resources)

Anyway, there are some "tricks" RPN allows the programmer to use that I do not know if AOS does. In 1988 I was asked by a topographer to develop a program to compute a triangle area given its three sides in an HP11C. He asked the program to be as small as possible, and he also wanted to understand what the h... was that stack. I wrote him the following program:

001- 42 21 11  LBL A
002 - 36 ENTER
003 - 43 33 R^
004 - 40 +
005 - 43 33 R^
006 - 43 36 LSTx
007 - 33 Rv
008 - 40 +
009 - 43 36 LSTx
010 - 33 Rv
011 - 33 Rv
012 - 20 ×
013 - 34 x<>y
014 - 43 33 R^
015 - 2 2
016 - 16 CHS
017 - 10 ÷
018 - 20 ×
019 - 43 36 LSTx
020 - 43 11 x^2
021 - 40 +
022 - 34 x<>y
023 - 10 ÷
024 - 11 SQRT
025 - 43 24 COS-1
026 - 2 2
027 - 20 ×
028 - 23 SIN
029 - 20 ×
030 - 2 2
031 - 10 ÷

Just enter the sides in X, Y and Z and run the program: the area of the triangle is the resulting data. I remember I fused two or three algebraic expressions in only one to get to the program. Some months ago (about 13 years later), when collecting my precious data, I found the program listing and tried to restore the original expressions. Who in Heaven wonder what did I do... I simply cannot figure out the original expressions. I depicted the program step by step and I found an 'I-never-saw-that-before' algebraic expression that does not even resemble any triangle-area computing procedure. And I know this is the way I've been programming since I saw one of the most beautiful use of RPN: Paul Baker's program to find the roots of a second-degree equation using FOCAL (HP41). I'd be proud of myself if I wrote it. I include its listing here.

01 LBL "SOL"
02 ST/ Z
03 /
04 -2
05 /
06 ENTER^
07 ENTER^
08 X^2
09 R^
10 CF 00
11 X>Y?
12 SF 00
13 -
14 ABS
15 SQRT
16 ST- Z
17 X<>Y
18 FC? 00
19 +
.END.
I depicted the program as deeply as I could, and sometimes it's easy to identify parts of the expressions for the two roots, sometimes mixing both real and complex parts. After this program, my programming style changed because I was always trying to find the shortest, fastest, more efficient program. And by doing this, the solution procedure always goes farther than the math notation.

I believe everything else I write from now on will be more based on my own thoughts (as if I didn't do it since the first words in here...) than in the subject itself. Many thoughts expressed in this thread are against my own preferences, but they are right. In more than one time the word "option" was used; after this, any particular preference is, indeed, a matter of preference. If any path leads to Rome, all of them are correct.

I know this does not exhaust the major theme, so I expect comments, suggestions...

Cheers.


#11

right on.

Regarding RPN vs AOS speed of entry, I must note that most adding machine type of financial desktop calculators use an rpn style of addition and subraction. Ten-key as I learned it isn't taught strictly AOs for a very good reason.

Regarding RPN vs AOS and education. Sure, my $20 casio will solve a lot of problems for linear algebra, some trig, and even some basic stats in AOS. but I don't have to *understand* the equation to "WYSIWYT" (T for type) it into a claculator. Educationally, I get a LOT more out of rpn, or even old ti-59 AOS than I do the modern variants. (I include DAL in this)

For programmming- thanks for that thought treain, Luiz! I was thinking strictly in "CS theory" instead of programming practices, documentaion, and style. I'll still claim the 41 and/or 48 teach a lot more about computer science than VB6 on a winders box, though :)

-C


#12

HI;

When I was attending classes for Neural Networks I used an HP49G to develop all programs, even the final implementation. It did not run this particular implememtation till the end (too slow), but we compared the values for the weights after 20 loops and they were exactly the same as the ones obtained by a C-program. The detail: the C-program directory was about 80KBytes long (text based, no graphics) and its listing was about 5 pages long. The HP49G equivalent was less then 300 bytes long and, by using the same font type and sheet size, half a page long.

Cheers.

#13

Hi Luiz,

Thanks for your interesting triangle area program, using only stack manipulations and Lastx. It certainly illustrates what clever things can be done with the stack alone, but also -- as you have said -- how difficult it is to decipher it later.

As far as I can see, you chose in the program not to use the 3 sides directly in the Area = SQRT(s(s-a)(s-b)(s-c)) formula (where s=(a+b+c)/2), but rather to solve for an angle first, using a half-angle formula combined with the law of cosines, and then to use the formula Area=
(bc*sinA)/2. That's the way it seems to me at first look, but I may be way off the mark -- I need to review how the stack works.

Trying to figure out your creative little invention reminds me of what John Smith said a few days ago about RPN programming, and of why I largely abandoned programming on my HP 25 and HP 15 when the HP 71 came around, allowing me to use BASIC on a pocket-sized computer/calculator. For on the HP 71 the program for the triangle would look something like this:

10 INPUT "a=";a

20 INPUT "b=";b

30 INPUT "c=";c

40 s=(a+b+c)/2

50 x=SQR(s*(s-a)*(s-b)*(s-c))

60 PRINT "Area=";x

My feeble imagination finds this easier to view, if maybe not quite so much fun!

Cheers, Tom

P.S. My wife is from Brasil, but please don't try Portuguese on me! Your English is superb!


#14

Hi again Luiz,

I checked the stack operations, and they confirm that you probably used the following expressions when you wrote your triangle program 13 years ago:

(Using a half-angle formula), cos(B/2) squared = 1/2(1+cosB) = (using the law of cosines) what winds up on the stack before you take cos-1 to get B/2, then B, then sinB

Area = ac(sinB)/2

How in heaven's wonders did you see how to translate this into stack operations?

All the best, Tom


#15

Hello, Tom. (say 'ôi' to your wife, please)

Thank you for adding this information to my post. Now that you mentioned, I remember the topographer gave me these formulas (the ones he used) and asked me to use them, so he would try to understand the stack operations.

Now I understand why did he took so long to call me back...

The first version of the program used R0 to hold 2*S (or [a + b + c]), but I changed it so it would not use R0 anymore, just the stack. If you look again at the program, steps 2 to 14 are there just to "organize" stack contents; previous version used R0 and only 7 steps to do so.

The program became 4 steps longer (4 bytes); a good choice instead using R0, that is 7 bytes long: 3 bytes won (in a time when 300 GigaBytes HardDisk space is the least for a reasonable machine, what can be done with 3 bytes...)

Well, time will tell about RPN/RPL and the new RPN appeal that Hewlett-Packard is about to call to its new machines. I'll be waiting to see...

Thank you for your enhanced comments. I hope I can keep my English under improvemment, also (thank you, D.B.!). Please, allow yuor wife to read this and answer:
"Eu sou de Minas Gerais, Araguari, perto de Uberlândia. De onde você é?"

Best regards.

#16

When debugging programs that make stack gymnastics, I have found the "stack trace" option to be invaluable.

To avoid wasting miles of thermal paper, I use the HP-IL serial interface linked to my PC. I designate the serial adaptor as the printer and set flags 15 and 16 to activate
the stack trace.

What it does is that after *every* instruction, it prints the instruction and all the stack registers.

**vp

#17

I never even used a VCR until VHS was well entrenched, but I read a very interesting book about the development of the VCR which discussed the competition between VHS and Beta. I think the main title is "Fast Forward" - I don't find it on my bookshelf right now. As I recall, the book said the thing that gave VHS an edge was the 2 hour recording capability compared to 1 hour for Beta, a limitation imposed by the smaller physical size of the Beta cartridge. Since most movies on TV last 2 hours, Beta couldn't be relied on for unattended recording. Beta was later extended to 2 hours at lower resolution, but VHS was extended to 6 hours. So VHS won on a price/performance basis, performance including recording time. In my opinion, NTSC[the North American composite video standard] video (at least - I haven't used PAL or SECAM) has such poor resolution, the signal degradation introduced by the VCR doesn't matter much - the viewer's imagination is doing most of the work. I think HiFi audio recording makes the 6 hour (EP or SLP) recording rate essentially as good as the 2 hour (SP) rate, and better if you have commercials to fast-forward through!

BTW, is it true that in Germany TV broadcasts include a signal to pause the VCR during commercials while recording?

Actually, I have a tiny bit of experience with PAL: I have viewed PAL satellite signals and the output of my recently acquired BBC Model B (without color) on an old NTSC television with manual controls. I understand PAL is quite similar to NTSC except for the number of lines per field (and correspondingly different vertical scan rate) and the color subcarrier frequency. I have read that SECAM is a lot different and American TV people say SECAM stands for "System Essentially Contrary to the American Method"!

The book I mentioned has a very interesting history of Sony. After the war, during American occupation (I believe this is when Sony was founded), plastics of all kinds were in short supply in Japan. Sony was working on a home video recorder and since they couldn't get plastic, they used paper as the substrate for the recording tape. Sony was one of the companies that paid Bell Labs a $25,000 license fee to learn all there was to know about transistors. When they developed the 3/4 inch U-Matic system, their goal was a home VCR. It became a standard for broadcasters and made the "Minicam" possible. I think the book said U-Matic didn't make it in the home market because of a combination of cost and the large size of the tape cartridge - maybe ironically, reducing the size of the cartridge was one of the efforts to make a system more adaptable to home use.

Another interesting book which I also found on a cut-out table (a third one is titled "Five Billion Vodka Bottles to the Moon", by a Russian radio astronomer) is "Game Over", about how Nintendo took over the video game market (this was before the N64 and PlayStation)(although I read somewhere else recently that PlayStation started out as a prototype submitted to Nintendo for a CD-ROM storage system when they were developing the N64, before they decided to stick with semiconductor ROMs, which live on cards, which might be telling- ). This book has an interesting history of Nintendo and the family that runs it. They had been in the business of making playing cards for a traditional Japanese game for a long time. In recent years, Japanese gangsters had adopted the game for gambling and developed the habit of using a fresh pack of cards for every game, to cut down on charges of cheating. The family's business expanded so much, they found automated methods to make the cards and became very wealthy. They went into arcade games and this led them to electronic games. I think it is very interesting that while they are not at the top of the video game business anymore, they had a lot of success with PokeMon, which, once the kids were hooked, became the habit of collecting cards!


#18

Just a "technopolitical" factoid regarding broadcast formats:

I learned of the existence of different braodcast formats while stationed in then-West Germany in the late '80s, using a multi-format VCR with my American (NTSC) TV. The format listing showed that West Germany used one type of PAL (there was PAL-1 and PAL-2), while France and East Germany used SECAM. The Communist East German government, you see, didn't want its captive populace to get West German news.


#19

actually the difference between PAL and SECAM is not the oscillating frequency, but in the colour coding.

So looking to a PAL (SECAM) boradcast with a SECAM (PAL) tuner will give a B&W image.

Now most tuners are PAL and SECAM compatible, and a good part of them also include NSTC...


#20

There are different PAL species. PAL means "phase alternating line", and is a method of coding the color information in a manner which averages phase information between two successive lines, to so cancel some of the error these signals may have. This correction means that PAL TV sets don't have the Tint adjustment NTSC equipment have.

Differences in AC mains frequency (60 Hz -> 525 video lines; 50 Hz -> 625 video lines) and channel frequencies allocation also create subtypes of video standards, often designated by a single letter. Some cases I know:

Germany (and many european countries): PAL-B (625 lines)

USA (and many other countries): NTSC-M (525 lines)

Brazil: PAL-M (525 lines)

Argentina: PAL-N (625 lines)

These values may seem arbitrary, and some think, as mentioned in the previous posting about East and West Germany, that politics had here a role to play. Some people believed in the same way about the different standards set for Argentina and Brazil in the 70's. But the true is that the geographical location (America, Europe) and the mains frequency had a lot more to do with this. Given a slight technical advantage for PAL over NTSC; almost all the game is set. (At least until digital TV gains more momentum).

Most TV sets and home VCRs in Argentina are tristandard, to be seamlessly compatible with NTSC and Brazilian PAL-M, apart from the local PAL-N signals. Camcorders tend here to be just plain NTSC.


#21

Although a PAL receiver can display a SECAM broadcast in black-and-white and vice versa, there was another difference between Western and Eastern European broadcasts: the frequency of the audio subcarrier (6.5 MHz in the East, OIRT standard, 5.5 MHz in the West, CCIR.) So the poor unfortunate East German, stuck with a SECAM-only television set, was not only stuck with watching Western broadcasts in black and white, he also had no audio.

I don't know about East Germany, but in Hungary where I used to live, most TV sets sold were already PAL/SECAM capable; and even those that were SECAM-only (and many older black-and-white sets) had the extra filter needed for 5.5 MHz audio. And if you had a set that didn't, there was a small cottage industry of TV servicemen happy to "upgrade" your set with a home-made solution. I imagine it wasn't that hard to come by a PAL/SECAM set in East Germany either, or one with CCIR audio.

This (to keep the subject somewhat on-topic) came very handy in the early 80s when home computers began to appear on the market, making it possible to use existing TV sets with Western home computers producing a PAL signal. It was not at all unusual in Hungary to see a Commodore 64 or some other early home computer hooked up to a 1970s or late 60s vintage black-and-white tube TV set. The lack of color was a great deal more tolerable when you at least had sound!


Viktor


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