Calculate! June 2005
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P R E S E N T E D B Y C A L C G A M E S
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TABLE OF CONTENTS
...The.Future.of.TI.Calculators..........................
...Programming.Tutorial.of.the.Month.....................
...The.History.of.Calculators:.Reverse.Polish.Notation...
...Letter.from.the.Editor................................
Newsletter Staff
Newsletter Editor:
Andy Janata <andy@calcgames.org>
Contributing Editor:
George Limpert <redux@calcgames.org>
Also Contributing:
Matthew Offner <darksideprogramming@yahoo.com>
Neil F. <korkow@gmail.com>
----- The Future of TI Calculators ---------------------------------------------
by George Limpert <redux@calcgames.org>
We've had the poll up for quite some time asking what people want to see added
to a new calculator. And when the question is asked, the usual responses are
given. People want a faster processor, more memory, or even a color screen.
Those are certainly nice improvements. But if TI released a calculator with all
of those, I wouldn't be impressed.
I'm the proud owner of one of the first TI-89s to roll off the assembly line. I
bought my calculator late in 1998 and haven't bought a new TI calculator since.
While one might think a six and a half year old calculator would be obsolete, I
don't feel like I'm missing much. Sure, TI calculators have bulked up on memory
and faster processors like Jose Canseco using steroids, but there's not really
any amazing new features for a long time.
My first calculator was a TI-85. I remember its predecessor, the TI-81, and the
TI-85 was a huge leap in functionality, memory, and processor speed. The link
port was a great addition as well. And then came the TI-92. While I'm not too
impressed with three dimensional graphing now, it was a cool new feature. Throw
in an improved computer algebra system that can give me answers with variables,
some flash ROM, put it in a handheld form, and you have the TI-89. Since then,
TI has put the car in neutral. They've got the pedal to the metal but aren't
going anywhere.
You can put a powerful engine in a car and give it a nice new paint job but if
I have no clue how to drive it, it's useless to me. That's exactly how most
users view TI calculators. It's nice if my calculator can solve a math problem
in five seconds instead of ten. But if it still takes me five minutes to figure
out how to type in the problem, I'm not going to be very impressed. While new
calculators are faster and have more memory, they're still as difficult to use
as ever.
TI has made some efforts to reach out to ordinary users. They've made an effort
to make calculators more useful through flash applications. And while that's a
great idea, most of the added functionality was impractical and only available
if you pay money to buy the applications. It was about as successful as the New
York Yankees this year in April.
Most users don't know how fast the processor in their calculator is or how much
memory the calculator has. And they don't care. All most people care about is
using their calculator for math help and to play a few games in class. If it
just works, they're happy. They'll never notice the added power under the hood.
It's not that TI shouldn't add better hardware to their calculators, but calcu-
lators have fast enough processors and enough memory to do most math problems
and run some pretty good games. I know that's dangerously close to an infamous
line about 640 kilobytes being enough for anyone, but in this case it's true.
Instead, TI ought to concentrate on making their calculators more useful and
usable.
The catalog menu hasn't changed much in the past ten years. Sure, there's more
options on newer calculators, but it's the same old menu. And when I scroll
through it, I have no idea what most of the functions do. I'm sure most of them
are very useful, but I don't know what they are let alone how to use them. That
makes it pretty useless to me unless I already have some knowledge of what I'm
looking for. Unless I carry my manual around with me, I'm missing out on most of
my calculator's functoinality. And it's just annoying if I know what function I
want, but I don't know what arguments it expects. Sure, my TI-89 gives me a
message in my status bar telling me if the function wants a string, a matrix, or
something else, but that doesn't really tell me what those arguments are. Take
the substr function for example. It's pretty obvious by its name that it takes a
string and returns a portion of that string. And it's nice to know it takes a
string and two integers. But I don't know what those integers are. Is it asking
for the starting point of the substring and its length, or is it asking for the
staring point and the ending point? The calculator isn't that intuitive to use.
I'm not asking for TI to store a copy of the manual on my calculator. All I want
is a little more guidance about what things do and how to use them. A little
help goes a long way in making the calculator more useful.
The calculator's interface could use a little work, too. There are keys on my
TI-89 which can have up to five different functions from the same screen. That's
confusing. While it's somewhat unavoidable in a compact design, an effort could
be made to simplify the keyboard layout. Adding a few extra keys isn't a bad
thing if it makes the keyboard more intuitive to use.
One of the nice things about the TI-85 was the custom menu. Instead of hunting
through the catalog menu, I could just add a few functions which would be just a
few simple key presses away. And while the custom menu still exists on newer
calculators, it's difficult to configure and just isn't very useful anymore. The
custom menu is a great idea, but it's been way too complicated.
I absolutely hate it when I type out a long equation only to find out I missed a
parentheses somewhere and have to search through it to find out where. HP had
the wonderful idea of adding an equation writer. Sure, it's not as simple as it
could be, but it saves a lot of typing. It's hardly a new idea and it could make
the calculator a lot easier to use, but TI has avoided adding the feature.
There's one recurring theme in all of these ideas. Make the calculator easier to
use. I don't care how much memory my calculator has or how fast the processor
runs. I'm not interested in a more powerful calculator. But if you show me a
calculator that's easier to use, I just might be interested. This is the atti-
tude most ordinary calculator users have. This is what people have been saying
for a long time. If TI wants to sell more calculators, they just might have to
listen.
----- Programing Tutorial of the Month: Text Output ----------------------------
by Matthew Offner <darksideprogramming@yahoo.com>
Editor's note: This is the first of a series of BASIC programming tutorials.
Next month: Input Methods.
Hello, my name is Matt Offner, alias Lord Mathias of Dark Side Programming, and
I'm one of the new content managers for CalcGames. I've been put in charge of
doing a monthly feature on programming tutorials. Note that this is for the 8x
series (83/83+/83+SE/84+/84+SE), so if you have something different, the syntax
will be different. It is also possible that in the near future this and other
programming tutorials will be authored by other news staff or members for the
other calcs.
This month we're going to cover display methods. This is the most important
part of programming, because without displaying anything, the user won't know
what's going on, and will not be able to make an intelligible input.
The easiest way to display output is using the Disp command. The Disp command
outputs to the homescreen. Of course, there are two types of output: text, and
everything else. For example, to display the real variable A, the code would be:
Disp A
To display the matrix A, the code would be:
Disp [A]
To display the text CALCGAMES.ORG, the code would be:
Disp "CALCGAMES.ORG"
Now, the Disp command has a very useful feature: the programmer can "connect"
things to be displayed using a single Disp command. So instead of using:
Disp A
Disp [A]
Disp "CALCGAMES.ORG"
you can use:
Disp A,[A],"CALCGAMES.ORG"
If you have more than 7 things to display, use the Pause command to pause the
display so the screen doesn't scroll after 7 displays:
Disp A,B,C,D,E,F,G
Pause
Disp H
Now, using the Disp command without anything after it displays the home screen.
Another way to display information is using the Output command. The Output
command is used as follows:
Output(X,Y,output)
where X is the row, 1 to 8, and Y is the column, 1 to 16. So to display
"CALCGAMES.ORG" at row 4, column 2, you would use:
Output(4,2,"CALCGAMES.ORG")
The Output command can be used to display the same variables as the Disp
command.
To display output to the graph screen, use the Text command:
Text(A,B,Output)
where A is an integer between 0 and 57 and B is an integer between 0 and 94.
The Text command can be used to display the same formats as the other commands.
The Text command may be used in a similar way to the Disp command:
Text(0,0,"CALCGAMES.ORG ",?)
Now, for the 83+/84+, the Text command has a little-known feature: the ability
to display regular size text on the graphscreen! This text is the same size as
the text you see on the homescreen, and is used as follows:
Text(-1,0,0,"CALCGAMES.ORG")
This concludes the first lesson. Stay tuned for new lessons in each month's
newsletter. Happy programming!
----- The History of Calculators: Reverse Polish Notation ----------------------
by Neil F. <korkow@gmail.com>
When pocket calculators were first introduced to the public, and HP led the way,
the method by which you would evaluate a problem on a calculator was much
different than we do today. This new method of computing, called Reverse Polish
Notation, or RPN, was much a much cheaper and easier to program way of solving
problems. If you look at almost any HP calculator earlier than about 1985,
chances are, it will use this method.
So, what exactly is RPN? Invented by a Polish mathematician named Jan
Lukasiewicz in the 1920's, his original intention was of course nothing to do
with computers, but rather to quickly simplifly complex equations, and remove
brackets entirely. In the 1950's, an Australian computer scientist realized how
much easier RPN would make programming calculators be. By 1962, RPN was being
used to make one of the first calculators ever... although they still was about
the size of a room!
Enough history... How does it work? To evaluate a simple equation on a modern
calculator such as '4+5', you would type in 4+5=, and it would output '9'. But
with Reverse Polish Notation, you would type 4[enter]5+. Why is this? To under-
stand how RPN works, you should have some number shaped pieces of paper and some
operand (eg. +,-,sin,sqrt) shaped pieces of paper. Let's assume that you want to
do 17+5. First you would take the '17' piece of paper and put it on floor. Then
you would put a '5' piece of paper on top of it. Finally, you take out a '+'
piece and the magic inside of it makes the first two pieces on the stack add
together. Do you get it now? Time for some "more complex" equations. Now say you
want to do '(5+2)*4'. Okay, let's get jiggy with this problem! Because '4' is
the last number to be evaluated, we put it on first. Next we put on 2, then 5.
So the stack would look this (let's say you put the number shaped papers under
each other instead.)
3. 4
2. 2
1. 5
When you take out your magical '+' piece, it adds the first two numbers (5,2)
together! So now the stack looks like this:
2. 4
1. 7
Next, you take the '*' piece and it multiplies the first two numbers together.
Now we have our answer and the stack looks like:
1. 28
If you were to do that on a calculator, you would type 4[enter]2[enter]5+*
One last thing. To evaluate problems like 'the sin of 5' you would type in
5[sin]. Also, if you haven't noticed, you never push [enter] for the last
number. If you are having trouble with an old HP, keep in mind that most HP's
can only have 4 numbers on the stack! I hope you have learned much from this.
----- Letter from the Editor ---------------------------------------------------
by Andy Janata <andy@calcgames.org>
I apologize for this newsletter being so late. The original plan called for
redux to do the next one, with a lot of interviews. That was months ago by now.
I'm putting this together now simply because there hasn't been much activity
lately. I also apologize for the lack of content. I was hoping to have more for
you, but people haven't been delivering like I'd hoped. I'll have an interview
(or two) for you next month, and we'll have our sections back.
My plans for the newsletter include interviews of prominent programmers as well
as our own staff. Some of you probably know very little about us, so we'll tell
you a bit about us. We have another tutorial already written for next month, and
work will start on the third part soon. "The History of Calculators" very well
may become a monthly staple of the newsletter. Of course, there's always going
to be a Letter from the Editor. Other possible sections include articles that
look closely at one or two projects over a couple months. We're working on set-
ting up a Top Program of the Month award. There are a lot of changes in the
works here at CalcGames.
Barrett may have gone on a mission and redux may be moving on, but there are
plenty of new people moving in to take their place. We hope you've enjoyed this
newsletter and look forward to next month's edition.
As always, we're open to questions from our readers about community history,
calculator help, or anything else of interest. If you've got something you'd
like to ask or contribute to the site (as a content page, news item, or news-
letter article), please mail it to editors@calcgames.org.
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The parts of the newsletter not written by CalcGames
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