Simpleton Geek Teaches Computer Programming Book 2 Ch 9

9. Arithmetic
9.1 Simple calculator
“Does anybody know what a computer does?” asked the teacher.

“It plays game!” “It makes music!” “It does web and e-mail!” answered the students.

“He computes.” said the teacher.

“HE computes?” the students were confused.

“Sure. We're talking about the original computer. Computer as a profession, instead of a machine. So, this is all before Charles Babbage and his Differential Engine.” Of course, the explanation went over the head of the students. They're still in high school, after all.

“And what about modern computers. You say it plays games?” asked the teacher.

“Yes.”

“Well, underneath, it's still the same: shuffling numbers. Loading and saving data, but shuffling numbers, mostly. There is an exception to that, however. In the future, we may not be dealing with bits and bytes.” He surveyed the class. “We may be dealing with qubits.”

“Qubits? What are they?”

“It's like a bit, but it can be 0,1 or both.”

“I'm sorry, teacher, but I don't understand.”

“That's fine. Neither do I, to be honest. As the venerable Richard Feynman said, 'if you think you understand quantum physic, it means you don't.' So, don't be too hard on yourself.”

The students are all waiting patiently for the other shoe to drop. They are now used to long periods of peace, punctuated by moments of sheer terror.

“Of course, that doesn't mean that you can slack off and not understand basic skills necessary to the functioning of every day life! With that comment, I think we should explore STRING functions. I hope you understand that once you learned strings, you will find that it is a better solution to your data storage as to make RESTORE-DATA keyword obsolete!”

“What? You mean we can't use them anymore?” The students are having trouble accepting the fact. “But teacher! We spent so much time learning them, and we're really good at it! Why can't we use them anymore?” The students were disappointed. Does that mean they're spending a lot of time learning obsolete concept? Why even bother?

“Of course, you can still use it. It's just that I don't think you want to do it when the alternative is much better than that. Why bother learning how to crawl, when you will be walking eventually? Because you need to! It's too much to try to learn everything all at once, so you need to be eased into the concept. Remember when I talked to you about growing?” The student remembered. Broken branches and all that. “There are many ways to do something, and the problem is everybody is different. So, the only way to PROPERLY learn computer programming, is to learn as many different techniques as possible, and pick the best one for your use.”

“Which one is the best one?” asked Nancy.

The teacher stamped her head immediately. “Didn't I just tell you to pick the best one? Do you even think about what you're saying?” Of course, with Nancy, that doesn't happen too often.

“Anyway, in the course of developing your computer programming skill, you will learn so many different languages, each with its own strength and weakness. No one can tell you what's the best language to learn. If he does, he's wrong!” 

Simpleton Geek Teaches Computer Programming Book 2 Ch 8D

8.4 Learning vs. Practice
“That was quite a fun session.” Peter admitted. He was in the teacher's office after class, per usual.

“Sure is. The songs you guys wrote are rather stilted, but it can't be helped. Playing it by ear is difficult enough, but without proper music theory, the tempo is rather robotic.”

“But the programming demands that the tempo is robotic.”

“Of course, not! The way I showed you is that tempo is a ratio of one note over another. However, it can easily be the number of jiffies.”

Peter did a face palm. “That's true. I didn't think of it!”

“Ha, it's best if you try to think of three different solutions to a problem. Each and every time.”

“So, each new problem will demand 3 different solutions?”

“Nope. Each problem. Even if you have encountered the problem before, try to come up with 3 different solutions.” said the teacher.

“But what good is it? I'll just come up with the same 3 solutions. So the time is wasted.”

“Not quite true. As your computer programming skills grow, you will come up with better solutions. The number of answers far outnumber the number of problems. Trust me in this that you will think of many new and novel solutions to existing problem.”

“Can you give an example?”

“Take the piano program. Do you see the text on top screen?”

“Sure, you had us print those characters in the shape of the keys.”

“That's a new solution. Traditionally, you would have computed the regions, and do a lot of calculations. Alternatively, you would have stored the data in arrays. Furthermore, you wouldn't be using letters to represents the notes. You would have been using numbers.”

“But your solution uses musical letters and you print them up on top screen.” said Peter.

“Exactly. That's new. Something I came up with. The reason is because you're just learning arrays, and frankly, without proper loops programming, it's just a pain. Loops make array programming an easy task, indeed.”

“So why not learn loops now?”

“Because, believe it or not, BEEP is a whole lot easier to learn than loops.”

“Well, I've learned some loops before, and it's not too bad.”

“In fact, they're rather easy. The reason is that they are conforming to structure. Well-structured programs are rather easy to do. However, compared to BEEP command, BEEP command is hands down way more simpler than loops.”

“Hmmm. It's true that BEEP is simpler than loops.”

“Also, the reason that I'm using musical letters is to facilitate your eventual lessons in music using MML.”

“MML? There's something about that in the Help menu. It looks extremely difficult.”

“It's rather confusing. However, at the heart, it's very simple. Notes are given by letters, tempo by numbers. There's more to it. Some commands for octave shifting, for example. But in simple terms, that's about it.”

“And this is not taught in school? Only you would do it this way?”

“That's correct. That's the difference between me and academia. You see sound and music are being put last. That's academia. I simply concentrate on what's doable and FUN.”

Simpleton Geek Teaches Computer Programming Book2 Ch 8C

8.3 CLS,PRINT,LOCATE,CSRX,CSRY+On screen keyboard
“Does everybody have their design on the journal?” asked the teacher. He asked the student to draw some lines and squares on the 32x24 graph paper.

“Yes, teacher.”

“Good. Now, I'm going to show you this program, and you're going to program it. This here is a good test to see if you can convert from English to Computerese. Or, as any professional will tell you, from Pseudocode to Smile Basic (Petit Computer).”

ASCII ART PAINTER

1. Clear top and bottom screen

2. Set array for text graphic characters

3. Main Loop

1. left/right changes character.

2. Print character on top at (0,0)

3. if touch screen then

1. Print character on X,Y.

“And that's it! Pretty simple, eh? Any question?” the teacher asked.

“What kind of array for text graphic characters?” asked a student.

“You look at the design, then find corresponding characters on the character sheet. Note the number, and store that into an array. Don't forget DIM, and choose your own variable name.”

“What do you mean left/right changes character?”

“You need to have a variable for array index. The value of the variable will vary between 0-max array. Remember that the value of max array is one less than the DIM value. You may use modulus arithmetic to do it. I'll show it to you later.”

“Where do we print the character if touch screen?”

“The touch screen condition is activated when the bottom screen is touched with a stylus. You want to print the character that is indicated on the array, as shown on the top screen, on the stylus location. One more thing: Make sure to include the character 0, so you can erase your drawing.”

As there are no more question, the students all started their programming. When the students reached the button reading code, the teacher showed a little piece of code to cycle the array index.

REM ASCII ART PAINTER

CLS:PNLTYPE “OFF”

CLEAR:DIM T[14]

T[0]=0:T[1]=144

T[2]=145:T[3]=146

T[4]=147:T[5]=148

T[6]=149:T[7]=150

T[8]=151:T[9]=152

T[10]=153:T[11]=154

T[12]=155:T[13]=156

U=0:'U=0-13

@LOOP

VSYNC 1:BT=BTRIG()

TX=TCHX:TY=TCHY:TS=TCHST

IF BT AND 4 THEN U=U-1

IF BT AND 8 THEN U=U+1

U=(U+14)%14:'KEEPING IT IN 0-13

LOCATE 0,0:?CHR$(T[U])

IF TS THEN PNLSTR TX/8,TY/8,CHR$(T[U])

GOTO @LOOP

Ten minutes later, most of the students have finished their programming, and started drawing their design on the computer. Some students, who have opted to get standard size, instead of XL version were struggling. They were not amused when their teacher showed a picture of magnifying glass holder. The teacher just laughed.

“Oh, by the way, in case you're having trouble with the small screen size,” the teacher showed his darkside, “you can easily modify the program to use the DPad for a cursor for the bottom screen. A button to print the character. B button to erase the character. X and Y button to cycle through the character, respectively. In fact, that'll be a good homework for you. Not that I'll be grading it! Gya ha ha ha!”

“Don't we need to show cursor for that?” asked Peter.

“Not really. Just erase the character if you draw it wrong! Although, if you really want to, you can use either BG command or Sprite command to show a cursor.”

“BG command?”

“Short for background. I supposed I should teach you about it one of these days, but not anytime soon! Gya ha ha ha!”

The students were feeling rather unappreciated. All these ungraded homework. Yet, they were resigned to do all of them, since failure to do the homework will result in low test scores. Mind you, their quiz scores were rather dismal even after doing all the homeworks, they dared not to imagine what their scores will be if they skipped doing their homework.

“Everybody got it?” asked the teacher.

“Yes, teacher. How can we save it?”

“You can't. There's no way to read the bottom screen. You need to save it in a separate array for it. I suggest a double dimension array to do it, although you certainly can do it using single dimensional array.”

“Double dimension array? What's that means?”

“Are you kidding me? You don't know what 'double dimension' means?” The teacher was looking around the class. Clueless faces abound. “Okay, you know that when you want to have more of the same variables, you use array? DIM and all that? Well, so far, we've been using single dimensional array. So, imagine that all variables are all in a line.”

The teacher drew a line, and put some numbers on it. Just like an axis.

“Now, a double dimensional array, will have another line.” He drew another axis. In fact, it looks suspiciously like the 32x24 grid representing the character screen.

“So, instead of having a single array index, we're using two array indexes. See this thing here? PNLSTR X,Y,CHR$()? If you have a two dimensional array representing a character screen, you can have it like this:

DIM SCR[32,24]

SCR[TX/8,TY/8]=T[U]

“You need to insert them in the appropriate places, but I'm sure you can do that easy!” Of course, the student were still ignorant of the issue, but with some not so gentle guidance, they were able to finally figure out what to do, and be able to modify the program so that the program will output a series of numbers so that they can copy the numbers into DATA commands for future drawing.

“This is actually the hard way to do things. It would be much simpler once you've learned loops.” said the teacher. “But I want you to suffer some more still! Gya ha ha ha!”

“So, how good are you at reading help file? We're going to skip to the end real quick and make some music! Not REAL music. We're going to do with using BEEP. That's right. Old computer 8-bit music. Now, I want you to write this program displaying the set of characters on top screen, and an ASCII picture of the piano keyboard on the bottom screen.” (Appendix E)

“For the main loop,” the teacher continued, “I want you to check whether or not the user touched the bottom screen, and if so, shows the corresponding character on the top screen. Let me know when you're done.”

Some of the students were having a little difficulty in implementing the program. The teacher encourage student discussions and help. “The best way to learn things is to teach things, so why don't you help your fellow students? By the way, here's the pseudocode I'm looking for:”

@LOOP

1. READ TCHX,TCHY,TCHTIME

2. CHKCHR(CURSOR LOCATION)

3. PNLSTR 0,15,CHR$

4. GOTO @LOOP

After some trial and error, all the students finally got it. “Great! Now I want to to open up the help menu and see the help page number 43, specifically the BEEP command. First, you notice that there is waveform number (0-69) and pitch. Scroll down to the bottom of the page and there is an instruction on how to do the pitch. Specifically, how P=4096/12. Also notice that there is a table called 'Changes to Musical Interval'. I think we all agree that it doesn't take a genius to realize that the letters are pretty much self explanatory. Notice that I put in the letter H at the end. That's equivalent to P*12, by the way. So, now, what we need to do is to create some look up table.

C=0 c=1 D=2 d=3

E=4 F=5 f=6 G=7

g=8 A=9 a=10 B=11

H=12

“Fortunately, when we do CLEAR command, all the variables are set to zero. So, when we do DIM notes later on, all the variables are still zero and all we need to do is implement the values above. I suggest that you create an array with 256 elements, and for each corresponding value in the table above, set the values in the character code entry. You know how to determine the character code for a character, right? Use ASC command! Here's the pseudocode that I want you to use:”

DIM N[256]

SET N[] ENTRIES PER ABOVE * P

@LOOP

1. READ TCHX,TCHY,TCHTIME,BTRIG

2. IF TCHTIME==1 THEN

1. A=CHKCHR(CURSOR LOCATION)

2. IF A!=0 THEN BEEP WAVEFORM,N[A]

3. SET WAVEFORM ACCORDING TO L/R DPAD

4. GOTO @LOOP

“Of course, I do not expect you to start from scratch! I expect you to modify the existing program! Now get to it! First find out what the character code values are using ASC command, then fill in the details.”

The students are busy typing '?ASC(“C”)' and other characters. After finishing the table, then they began to modify their program. All in all, it only took them about 10 minutes to do. Soon, the class is filled with electronic music!

“Now, does anybody know how to do karaoke?” asked the teacher. Of course, no one does. The students all stared blankly at the teacher. “Come on, now, show and tell time! What does a karaoke system entails?”

“Well, there's music.” said a student.

“Which is note and tempo. What else?”

“Words?”

“Correct, so we have note, tempo and words. Would this covers it?”

1. Note

2. Wait time (tempo)

3. Text

“So, what I want you to do next is to create DATA statements, consisting of those 3 different elements. We can just use the same program and simply write it after the original data. Press 'A' for automatic music! How's that?”

The students are all getting excited! Soon, they were getting busy. It's rather interesting how little it takes to write a worth while program. Animated text! Who would have thought of it?

IF BT AND 4 THEN DELAY=DELAY-1

IF BT AND 8 THEN DELAY=DELAY+1

DELAY=(DELAY+60)%60

@AUTOPLAY

READ NT$,WT,XT$

IF XT$==”END” GOTO @MAIN

BEEP W,N[ASC(NT$)]

PNLSTR 0,17,XT$

VSYNC DELAY*WT

GOTO @AUTOPLAY

Of course, there is more than one way to do it. This particular implementation, Appendix F, relies on the fact that notes are given in string. However, it can easily be done that the notes are given in multiple P blocks.

The data is set in @MUSIC DATA segment, and it does take a long time to do, even with copy and paste. The tempo is rather rough because it's very difficult, unless one is reading musical notation from song book. The text is currently limited to just one line, but there is no reason why the data cannot include text cursor positioning as well.

It does illustrate the point that computer programming, coding the program, doesn't take a lot of time. Once the design is decided, there is nothing to stop the computer programmer to just code the program quickly and easily. It is much more difficult and time consuming to write the data than it is writing the program itself.

The students were really having fun. In fact, some students decided to form an impromptu band. Some playing the beep, others playing drums. Some cat's meow can be heard as well.

The teacher simply leaned back on his chair. He enjoyed the situation. Of course, it would have been better with ear phone, but there's nothing inherently bad about making music with the computer, especially using the computer program the students wrote themselves. It is very encouraging to have the students write the tools as opposed to just give them the completed tools, a mysterious black box if you will, that is all-powerful but with all the features hidden.

“By the way, guys, you know that the sound can have up to 7 sounds? You can have polyphonic. Simply add an extra note, and READ statement, and there you have it!”

Simpleton Geek Teaches Computer Programming Book 2 Ch 8B

8.2 Debugging, TCHX,TCHY
“Alright, class, listen up!” The teacher was dumping a huge stack of paper on the desk. “Due to your extremely low performance last time, I decided to lower my expectation, yet again.” He was scanning the class angrily. “You know what that means, don't you?”

The whole class trembled with fear. There can be only one meaning: Terminator on the prowl. Their foreheads shall be stamped with 'FAIL'. It's not a question of if. It's a question of how many.

“So, I'm going to set my expectation to the lowest possible level. Failures to do this will mean being whacked on the head with this stamp!” He holds up a stamped marked with the words 'FAIL' on it. Except this one happened to be twice the usual size. Apparently the teacher has upgraded his stamper over the weekend. Fear descended upon the classroom.

“So, distribute this program. What I want you to do is simple: Copy the program exactly! Then tell me what's wrong with the program. The first one to give me the right answer will get 100 points. The rest will get zero. That's normal.” said the teacher. “However, I must tell you that you have to copy the program EXACTLY!” His eagle stare was really scary. “The ones who give me the wrong answer will get stamped on the forehead!”

The teacher smiled. “So get going! Remember, only one of you will get 100 points. The rest of you will get zero!”

All the students are busy copying the program. There are 3 pages of long, dense code. Definitely very hard to copy correctly. Written on the top of the page, is the task the the students must do: “There is exactly one thing wrong with this program. What is it?”

All the student furiously copied the program, trying to be the first to figure out what's wrong with the code. Somewhere by the bottom half of the first page, the students were shocked to see commands not covered in class. On the top of the second page, the students are surprised even more that some lines did not look like a normal structure. But when they got to the third page, they're in the shock of their life. So many nested parenthesis and digits! They must really, really be vigilant there! One missed digit, and it's head whacking time!

“Teacher! I got it! I found the mistake!” said Nancy.

“Great. What is it?” said the teacher.

“There's a syntax error on line 23.”

“Wrong!” said the teacher as he stamped 'FAIL' on her forehead.

“But teacher! It's true! See here? It says there 'Syntax Error'!” said Nancy.

The teacher stamped her forehead the second time. “Obviously, you need to check the code well, because that's not the mistake I'm looking for!” said the teacher. “Check your code.”

Sure enough, Nancy mistyped the command. Once pointed out by the teacher, it was easy enough fix.

“The real error lies on line 27!” said Nancy.

That earned her another stamp on the forehead.

“You need to fix that one as well. 3 stamps in one minute? Gya ha ha ha!” No doubt about it: Terminator on the prowl. “Yes, you found the mistake?” he asked another student who was raising his hand.

“Uh, let me check real quick. Nope. False error. I mistyped the code.” said the student.

“Good thing you caught that. Would have been bad if you didn't.” The student gulped.

“Teacher, I found it! Error on line 35!” said a student.

The teacher bounded quickly to the student. “Show me.” he said.

The student proudly showed the teacher the error message. That earned him a stamp on the forehead. “Show me the code next.” The student coiled in fear. Sure enough once the code is shown, the teacher pointed out the student's mistake. “You forgot to put enclosing quotation mark here.” The student almost cried in shame and embarassment.

“Teacher, I found the mistake! Syntax error on line 157!”

Another stamped forehead. “How many times do I have to tell you? Comparison takes 2 equal signs! Assignment only takes one. Whenever you do comparison, you need to put down 2 equal signs, not just one.”

“Teacher, I found the mistake!” said a student. The teacher was homing in with glaring eyes. “But, I better double check before I show it to you.” the student amended hastily.

“Sure.” the teacher wasn't pleased at all. “Just don't bother me until you're ready. Got it?”

“Yes, teacher. Sorry.”

The students are checking and double checking the code. Finally, a student raised his hand. “Teacher, I have it here!” said a student. The teacher, who by this time was snoozing, with his feet on his desk, woke up and walked to the student in question.

“So? What's the mistake?” asked the teacher.

“The program prints out garbage!” said the student. That earned him a stamped forehead. The teacher then went back to sleep at his desk.

“The program actually runs?” asked another student.

“Sure. You don't think I'll be giving you a program with a syntax error, do you? That would have been too easy! Gya ha ha ha!” said the teacher. All the students wailed in frustration! “Tell you what. Just work on it, and when the class ends, just show me what you got.”

It was close to the end of the class. “Teacher, will you check this out?” asked Peter.

“Sure.” the teacher went to Peter to see his program running. The display of shows the screen slowly filled with letters. It stops running when the screen showing “HELLO” in big letters. “So, what's the question?” asked the teacher.

“I can't find the mistake.” said Peter. All the student paused in their work. Of course, there is a mistake! That's the assignment!

“So, what you're saying then is, the program has no mistake?” asked the teacher.

Peter gulped in fear. He thought for a while. For a long while. Finally, he said, “Yes. I guess so.” he resigned to be stamped on the forehead. All the other students held their breath, waiting for it.

“Well, then I guess I need to give you 100 points, and the rest of the class got zero.” The teacher smiled.

“Huh?” said Peter. “Doesn't it say here there is a mistake?”

“Sure does.”

“But if the mistake isn't in the code...” Peter was thinking about it.

“Where could it be?” prodded the teacher.

“It can only be in the statement that 'there is a mistake' because there really isn't.” said Peter. The teacher just laughed. All the rest of the students threw up their hands in frustration.

“Teacher! What is the point of having us do this if there's no mistake?” asked Nancy, the most-stamped girl.

“The point is, you guys are all careless! You need to pay attention to details! You cannot skip a variable, a letter, or even a space! All the symbols must be accurate! Do you know what happens when you missed a mathematical sign?” asked the teacher.

“The program gives reverse answer?” said a student.

“In case of NASA, the rocket flipped over and there goes hundreds of millions of dollars in a flash!” said the teacher.

The students just don't know what to say.

“In another instance, the airplane in question was flipped upside-down as it crossed the equator!” The students were all silent. “Can you imagine what happens when such program is running a nuclear reactor?” The student shuddered. They don't need to be told the grave consequences that may arise from such scenarios.

“But teacher! How can we do it?” asked the students. “It's too difficult!”

“So, Peter, how do you do it? I assume you have a secret technique for counting those parenthesis.” asked the teacher.

“I counted the parenthesis. Add one for left parenthesis, and subtract one for right parenthesis. If I end the line, and it's not zero, I know I made a mistake somewhere.” said Peter.

“See? Easy as counting.” said the teacher. “How about the digits?” Copying numerous digits accurately is very difficult.

“I look for the most common digits in the sequence, then I counted the number of digits in-between that digit. Finally, I memorize the sequence 5 digits at a time. If I arrive at the digit separator and still have fingers left, I know I skipped some digit. If I ran out, then I know I double counted some.”

“And there you go. That's how you do it. By the way, there is a way to memorize long sequence of digits. Using mnemonic.”

“Mnemonic?” The students were unfamiliar with the technique.

“Do you know the song 'This old man?' That's a sample of mnemonic. 1-wand. 2-shoe. 3-knee. 4-floor. So for a sequence 33241, you can create a sentence 'Double knees knocking the a shoe off to the floor, to be fetch with a wand.' When you say the sentence, you imagine the action. Then, when you repeat the sentence, you'll write '33' for 'double knees', followed by '2' for 'shoe', followed by '4' for 'floor', followed by '1' for 'wand'. Very effective technique.

“There are many different techniques. Benjamin Franklin designed one, where consonants stands for digits. All that's left is to choose words with the right consonants to memorize the numbers. With these kind of techniques, it's easy to memorize long sequences of digits.

“Of course, you need to memorize the key, and then you need to practice so that you can come up with the words effortlessly. But once you do, it's easy to memorize numbers.”

“So, teacher, that's how you memorize numbers?” asked a student.

“Not really. I developed a system where I use arithmetic operations. For that example 33241, I would memorize 'Two 3s, which is 2. 2 when squared is 4. 4-3, which is doubled in the beginning is 1. Something like that.”

“That's really a long way to memorize digits.”

“Sure, but you know, with practice, it'll take only 2-3 seconds. And I can memorize up to 9 digits, easy.”

“Really? Can you really do that?” asked the student.

The teacher shrugged. “That's the number of digits I have to memorize in Big Brain Academy. Sure.”

“Did I mention I scored rather high on Big Brain Academy?” the teacher asked. I forget exactly how high, but definitely over 2200 points. Of course, that's over a period of 10 weeks. You should try it sometimes. Big improvement for the first 6 weeks, and trickling improvement thereafter.”

The students were speechless. They have nothing to say.

“Anyway, we still have a few minutes, so let's write a program real quick. You remember TCHX and TCHY? Write this program:”

CLS:PNLTYPE “OFF”

?

?”A”*8;”B”*8;”C*8”;”D”*8

@LOOP

VSYNC 1

TX=TCHX:TY=TCHY:TT=TCHTIME

TX=FLOOR(TX/8):TY=FLOOR(TY/8)

IF TT==0 THEN P=0

IF TT==1 THEN P=CHKCHR(TX,TY)

LOCATE TX,TY:?CHR$(P);

GOTO @LOOP

“Now, tell me what you see.” asked the teacher.

“The bottom screen went blank and when we put the stylus on the position where the letters are, we get to see the letters repeated.”

“Correct. PNLTYPE “OFF” means to turn off the keyboard. Now, we're going to put some characters on the bottom screen. Add this line just after the line LOCATE:PRINT”

PNLSTR TX,TY,CHR$(P)

“Teacher! Now there's text on the bottom screen, just like the one on top!”

“That's because we echo print the line on the bottom screen. However, you can tell that these two lines are identical, except one goes to the top screen, and the other goes to the bottom screen. That's how you print on the bottom screen.”

LOCATE TX,TY:?CHR$(P);

PNLSTR TX,TY,CHR$(P)

“How do you read the character on the bottom screen?” asked Peter.

“There's no way to do that. It's not supported by the language. You need to keep track of that yourself. We'll do more of these things tomorrow. For now, though, you have a rough draft for a simple ASCII painter program.”

The students played with it some more. They tried to understand the program but there's nothing difficult about it. There are only two different commands: PNLTYPE and PNLSTR.

“Homework will be to figure out how to clear the bottom screen. Knowing that there isn't PNLCLS command available to clear the bottom screen. That's right. You have to do it yourself!” said the teacher.

“More homework. You want to copy these until you get 100% accuracy. I won't be scoring these, by the way.” The teacher began to distribute papers filled with program listings. There are various commands written down on paper, and they look random.

“What kind of program is this?” asked a student.

“It's not a program. Just some random lines. It won't run.”

“Then why are we doing this?”

“You need to familiarize yourself with the different commands. Practice these to avoid syntax error! You certainly don't want to forget how to spell certain commands. Also, it's good to introduce you to commands you may otherwise will miss. Remember, practice makes perfect. Gya ha ha ha!”

Simpleton Geek Teaches Computer Programming Book 2 Ch 8A

8. Panel Str + Complicated program
8.1 Do what you did, only different

“Nancy, how come the Princess killed the Dragon AND the Prince?” asked Linda. “Shouldn't the Princess end up marrying the Prince?” Linda was seated next to Nancy, and was trying out her text adventure program.

“That's a bad ending. I need to put in a bad ending in there, right? So, you need to bring the flower to the Prince, and kiss him, and hug him. Only then the Prince won't be drinking poisoned wine, becomes insane and tried to kill you!” Nancy currently holds the distinction of “having her head stamped with 'FAIL' the most.” The next closest student isn't even close.

“But, Nancy, I did all that! Something must be wrong with your program!”

“But I tried it and it works!” said Nancy.

“Let's see.” said Linda. She stopped the program and looked through the source code.

“Eh, you're not supposed to do that! You're looking through the source code! That's cheating!”

“I just want to make sure that I do it right.” said Linda. “Let's see. I was in the top of tower right after I kissed him. See here? There's only bad ending possible from here! You have a mistake in your program!”

“What?” asked Nancy. “Let me see that! Oh, that's because you haven't hugged the prince!”

“But I did!” said Linda.

“See, you kiss the Prince, and hug him!”

“No way! Hugs happens way before kissing!”

“Really? But it's the Prince! You don't hug him before kissing!”

“That's just in the movies! That's not what I do.”

“Well,” said Nancy. “That's why the Prince went insane and kill you!”

“That's not a very good story then!” said Linda.

“What's that?” asked Peter, who was just sitting down. “Your program is buggy?”

“There's no bug. Just a bone-headed story!” said Linda.

“There's nothing wrong with my program, and it's certainly not buggy!” insisted Nancy.

The bell rang, and the class settled down. The teacher walked in. “Bunch of failures like usual! There's only one passing score. Peter's. Everybody else can't even score a decent grade. Any question?”

“If the program doesn't work as it should, does that qualify as 'buggy'?” asked Peter.

“No.” said Nancy the ever optimist.

“Of course. Any deviation from planned performance can be considered a bug. Why do you ask?”

“Nancy's program is buggy.” said Peter. Linda nodded her head enthusiastically.

“But the program ran fine? There should be no bug.” said the teacher.

“Hugging before kissing is punished with death!” said Linda. The class was filled with laughter. The teacher thought for a while, trying to remember which story it was. “The dragon killing princess, right? That's not a bug.” Nancy stuck her tongue at Linda. “That's poor game design, with the usual outcome having the game dumped in discount bin.” Linda stuck her tongue at Nancy.

“By the way,” the teacher asked. “Does anybody know what's the first bug?” Nobody knows. “A moth.” said the teacher, smiling.