Here - 1000 BiT

More documents

Recommendations

Info

INSTRUCTOR NOTES 33 DEBUGGING, STOP, CONT uThe "sigh and moan" technique being a loser, our students need a bag of tricks which [^jhelp isolate program bugs, and should practice on programs they are writing as they gothrough this book. ^JThe inexperienced debugger feels hopeless inertia when "it doesn't work right." Rather ^than sit and stare, it is more useful to try some changes. Any changes are better than ^none, but random changes are very inefficient. The best changes are those which eliminatesections of the program from the list of possible hiding places for the bug. ^jAs programs grow in complexity, more of the bugs result from unforseen interactions Obetween separated parts of the program. The bag of tricks we offer helps find these also.Delay loops, PRINT commands and STOP statements help the student see how the ^program is functioning. t,Don't overlook those techniques you can use after the program is stopped with a STOP ^jstatement or a STOP key press. You can PRINT out any variable values you like so as tosee what the program has done. You can also do arithmetic in the PRINT command to ^Jcheck what the program should be doing. You can even change variable values (forexample, the value of a loop variable). When you are ready, CONTinue the program run. ^QUESTIONS:w1. How can you make the computer print ^JBREAK IN LINE 55 ^by adding a line in the program?2. How are the STOP and the END commands different?3. How are the STOP command and the STOP key different?4. What does the CONT command do? ^5. Why would you put STOP commands into your program? k^j6. How do delay loops help you debug a program? ^J7. How do extra PRINT commands help you debug a program? ^8. Why do you take the STOP and extra PRINT commands out of the program after youhave fixed the errors?^j9. Can you pick in what line the STOP key will stop the program? Can you pick using ^the STOP command?190
LESSON 33DEBUGGING, STOP, CONTTHE STOP COMMANDEnter and run:10 REM SECRET STOP20 PRINT "clr"25 R=INT(RND(8)*200)30 FOR l=0 TO 20040 IF I=R THEN STOP50 NEXT IThe program will stop, and the computer will peep and print a message:BREAK IN LINE 40What do you suppose the secret value of I was?Enter PRINT I (No line number)and find out.HOW TO START IT AGAINEnter the command CONT. Try it!"STOP" IS LIKE "END"STOP makes the computer stop and enter the Edit mode.It is like END except it prints the number of the line that the STOP is in.You can have as many STOP commands in your program as you like.STOP is used for debugging your program.191
Page 3 and 4:
KIDSAND THECOMMODORE 64
Page 5 and 6:
KIDSAND THECOMMODORE 64neoartment o
Page 7 and 8:
nTABLE OF CONTENTSAcknowledgements
Page 9 and 10:
nACKNOWLEDGEMENTS^My sincere thanks
Page 11 and 12:
nTO THE PARENTSThis book is designe
Page 13 and 14:
n~ ABOUT PROGRAMMINGThere is a comm
Page 15 and 16:
nn INSTRUCTOR NOTES 1 NEW, PRINT, R
Page 17 and 18:
COMMAND THE COMPUTERTry this. Type
Page 19 and 20:
THE NUMBER ZERO AND THE LETTER "O"T
Page 21 and 22:
nINSTRUCTOR NOTES 2COLOR AND THE KE
Page 23 and 24:
There are eight colors on the numbe
Page 25 and 26:
OTHER COMMANDS IN PRINT STATEMENTSJ
Page 27 and 28:
LESSON 3 LIST, BOXES IN MEMORYClear
Page 29:
ADDING A LINEYou can add a new line
Page 35 and 36:
THE DELETE KEYThe DEL key is your "
Page 37 and 38:
INSTRUCTOR NOTES 5 TRICKS WITH PRIN
Page 39 and 40:
RULE: The semicolon makes the invis
Page 41 and 42:
Assignment 5:1- Write a program whi
Page 43 and 44:
LESSON 6THE INPUT COMMANDUse INPUT
Page 45 and 46:
YOU WEAR TWO HATS, USER AND PROGRAM
Page 47 and 48:
LESSON 7THE LET COMMAND, GLUING STR
Page 49 and 50:
GLUING THE STRINGSHere is how to st
Page 51 and 52:
LESSON 8THE GOTO COMMAND AND THE ST
Page 53 and 54:
A CAN OF SPAGHETTILook at this: 10
Page 55 and 56:
Assignment 8:1. Just for practice i
Page 57 and 58:
LESSON 9 THE IF COMMANDClear the me
Page 59 and 60:
JtTHE "NOT EQUAL" SIGNTwo signs:= m
Page 61 and 62:
INSTRUCTOR NOTES 10 INTRODUCING NUM
Page 63 and 64:
The thing which is put into the box
Page 65 and 66:
MIXTURES IN PRINTYou can print numb
Page 67 and 68:
INSTRUCTOR NOTES 11TAB AND DELAY LO
Page 69 and 70:
HOW BIG A SPACE CAN TAB( ) MAKE?The
Page 71 and 72:
INSTRUCTOR NOTES 12 THE IF COMMAND
Page 73 and 74:
AN IF INSIDE AN IFThe "teenager" pr
Page 75 and 76:
2. Here is another program. What wi
Page 77 and 78:
LESSON 13RANDOM NUMBERS AND THE INT
Page 79 and 80:
ROUNDING OFF NUMBERSPerhaps you kno
Page 81 and 82:
INSTRUCTOR NOTES 14SAVING TO TAPEWe
Page 83 and 84:
The computer automatically turned o
Page 85 and 86:
nnr^nnnnnr^nnLOADING A PROGRAM FROM
Page 87 and 88:
5. We are ready to put in the next
Page 89 and 90:
n INSTRUCTOR NOTES 15 SOME SHORTCUT
Page 91 and 92:
AN INPUT SHORTCUTInstead of10 PRINT
Page 93 and 94:
WHEN TO USE THE COLON SHORTCUTUse t
Page 95 and 96:
But if we write this line in a prog
Page 97 and 98:
LESSON 16 MOVING PICTURESMOVING THE
Page 99 and 100:
Line 40 waits for you to see this b
Page 101 and 102:
LESSON 17FOR-NEXT LOOPSRemember the
Page 103 and 104:
LOOP VARIABLESTo make sure that eac
Page 105 and 106:
^ INSTRUCTOR NOTES 18 DATA, READ, R
Page 107 and 108:
STRANGE RULES1. It doesn't matter w
Page 109 and 110:
MIXTURES OF DATAThe DATA statement
Page 111 and 112:
LESSON 19SOUND EFFECTSTurn up the s
Page 113 and 114:
TONES BY THE BUSHELEnter: 10 REM **
Page 115 and 116:
"TM" stands for "timbre." Timbre is
Page 117 and 118:
INSTRUCTOR NOTES 20NAMES, CLOCKS AN
Page 119 and 120:
cAnytimeyou type, the characters ar
Page 121 and 122:
LESSON 21COLOR GRAPHICSADJUST YOUR
Page 123 and 124:
Add these lines to the above progra
Page 125 and 126:
INSTRUCTOR NOTES 22POKEing GRAPHICS
Page 127 and 128:
Try this: Change the number 83 to a
Page 129 and 130:
We can number the streets and house
Page 131 and 132:
n INSTRUCTOR NOTES 23 SECRET WRITIN
Page 133 and 134:
THE COMPUTER ISIMPATIENTThe compute
Page 135 and 136:
^ INSTRUCTOR NOTES 24 PRETTY PROGRA
Page 137 and 138:
Assignment 24A:1. The delay loop is
Page 139 and 140: Assignment 24B:1. Write a short pro
Page 141 and 142: LESSON 25 LOGIC: AND, OR, NOTANOTHE
Page 143 and 144: THE IF COMMAND TELLS LITTLE WHITE L
Page 145 and 146: THE LOGIC SIGNSYou can use these si
Page 147 and 148: LESSON 26 SNIPPING STRINGS: LEFTS,
Page 149 and 150: CUTTING A PIECE OUT OF THE MIDDLETh
Page 151 and 152: nnO INSTRUCTOR NOTES 27 SWITCHING N
Page 153 and 154: MAKING NUMBERS INTO STRINGSRun10 RE
Page 155 and 156: Assignment 27:1. Write a program wh
Page 157 and 158: LESSON 28ACTION GAMES AND THE FUNCT
Page 159 and 160: LOOKING IN THE KEYBOARD'S BOXHere i
Page 161 and 162: Run it. It puts a white diamond on
Page 163 and 164: cTHETARGETS ARE HEARTSAdd these lin
Page 165 and 166: LESSON 29MUSICGo back and review th
Page 167 and 168: REGISTER ADDRESSES Base address is
Page 169 and 170: D^ INSTRUCTOR NOTES 30 ARRAYS AND T
Page 171 and 172: The DIM... command tells the comput
Page 173 and 174: 1 REM *** EIGHT QUEENS ***2 GOTO 10
Page 175 and 176: Assignment 30:1. Write a program wh
Page 177 and 178: LESSON 31SPRITES FOR ACTION GRAPHIC
Page 179 and 180: Then use the CRSR keys to move the
Page 181 and 182: MANY SPRITES AT ONCEHere are the bo
Page 183 and 184: WATCH OUT, TWO SPRITES ARE GOING TO
Page 185 and 186: LESSON 32USER FRIENDLY PROGRAMSTher
Page 187 and 188: TIE A STRING AROUND THE USER'S FING
Page 189: SET TRAPS FOR ERRORSExample: Add th
Page 193 and 194: Use the PRINT command to look at va
Page 195 and 196: RESERVED WORDSABSAND ASC ATNCHR$CLR
Page 197 and 198: ells and whistlesA phrase going bac
Page 199 and 200: error trapPart of a program which c
Page 201 and 202: listingA list of all the lines in a
Page 203 and 204: emarkA comment you make in the prog
Page 205 and 206: variableA name given to a box in me
Page 207 and 208: FORMULA TOO COMPLEXYou wrote a stri
Page 209 and 210: SYNTAXYou "spelled" the line wrong.
Page 211 and 212: 1 REM A4-310 REM*** SMILE***13 POKE
Page 213 and 214: 1 REM A6-210 REM*** FAVORITE***15 P
Page 215 and 216: ~ 40 INPUT C$1 REM A9B-210 REM ***
Page 217 and 218: ^ 1 REM A11A-210 REM !"#$% INSULTS
Page 219 and 220: 1 REM A12B-410 REM *** PICK A CARD
Page 221 and 222: ^ 1 REM A15-210 REM!!! VACATION!!!r
Page 223 and 224: ■1 REMA17B-510 REM*** OPERA SOPRA
Page 225 and 226: 1 REM A22-110 REM *** COLORED BOX *
Page 227 and 228: 1 REM A24B-1r> 10 REM*** SUBROUTINE
Page 229 and 230: 1 REM A26-210 REM*** ANSWERER***12
Page 231 and 232: 1 REM A27-110 REM *** BACKWARD ***1
Page 233 and 234: 441 FOR l=2 TO LEN(A$]442L1$=MID$(F
Page 235 and 236: INDEX OF TOPICSaddition 59,74ADSR 1
Page 237 and 238: memory 16, 24-26, 45, 59, 81, 83,11
Page 239: nnnnnnonnnOnooonnnnnnnnonnnHnonnOn
show all

Here - 1000 BiT

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?