10  REM ***  HP TIME-SHARED BASIC PROGRAM LIBRARY  *********************
11  REM
12  REM         TUT02:  TUTOR SERIES BASIC LANGUAGE PROGRAMMING COURSE,
13  REM                 (PART 2 OF 25)
14  REM         36139 (A810) REV A -- 7/71
15  REM
16  REM ***  CONTRIBUTED PROGRAM  **************************************
17  REM
100  PRINT "WELL, I AM GLAD YOU MADE IT. I'VE BEEN WAITING FOR YOU"
110  PRINT "SO THAT WE COULD CONTINUE OUR LESSON. SO FAR WE HAVE COVERED"
120  PRINT "THE 'INPUT' STATEMENT, THE 'LET' STATEMENT (AND ITS SYMBOLS),"
130  PRINT "AND THE 'PRINT' STATEMENT. OUR SAMPLE PROGRAM LOOKS"
140  PRINT "LIKE THIS:"
145  PRINT 
160  PRINT "10 INPUT X,Y,Z"
170  PRINT "20 LET R=SQR(X^2+Y^2+Z^2)"
180  PRINT "30 PRINT R"
190  PRINT "40 END"
200  PRINT 
210  PRINT "WE CAN DO MUCH MORE WITH THE PRINT STATEMENT."
220  PRINT "BESIDES PRINTING THE VALUE OF A VARIABLE (IN OUR CASE 'R'),"
230  PRINT "IT CAN BE USED TO TYPE OUT LABELS. ANYTHING IN QUOTES FOLL-"
240  PRINT "OWING THE PRINT STATEMENT WILL BE TYPED OUT LITERALLY"
250  PRINT "SO WE ADD:"
251  PRINT 
260  PRINT "30 PRINT''THE RADIUS VECTOR EQUALS''R"
270  PRINT 
280  PRINT "BY USING STATEMENT NUMBER 30, WE CAN REPLACE THE EARLIER"
290  PRINT "ONE AND THIS IS THE WAY WE CAN MODIFY OR CORRECT OUR PROGRAM."
300  PRINT "THE PHRASE IN QUOTATION MARKS WILL 'LABEL' OUR VALUE FOR 'R'"
310  PRINT "WHICH FOLLOWS. WE CAN DO THE SAME KIND OF THING TO THE FRONT"
320  PRINT "OF OUR PROGRAM TO EXPLAIN IT TO A USER:"
330  PRINT 
340  PRINT "9 PRINT ''WHAT ARE YOUR VALUES FOR X,Y, AND Z''"
360  PRINT 
370  PRINT " (THE INPUT STATEMENT WHICH FOLLOWS WILL SUPPLY THE '?')"
380  PRINT "NOTICE THE '9' STATEMENT NUMBER. THIS STATEMENT WILL BE"
390  PRINT "EXECUTED BEFORE THE 'INPUT' STATEMENT IN 10. THIS DEMONSTRATES"
400  PRINT "WHY IT IS SO HANDY TO NUMBER STATEMENTS IN INCREMENTS. OUR NEW"
410  PRINT "PROGRAM NOW LISTS AS FOLLOWS:"
420  PRINT 
430  PRINT "9 PRINT''WHAT ARE YOUR VALUES FOR X,Y, AND Z''"
440  PRINT "10 INPUT X,Y,Z"
450  PRINT "20 LET R=SQR(X^2+Y^2+Z^2)"
460  PRINT "30 PRINT''THE RADIUS VECTOR EQUALS''R"
470  PRINT "40 END"
480  PRINT 
490  PRINT "WHEN 'RUN' IS TYPED, THE PROGRAM DOES THIS:"
500  PRINT 
510  PRINT "WHAT ARE YOUR VALUES FOR X,Y, AND Z";
520  PRINT "?"
521  PRINT " (TRY IT, TYPE THREE NUMBERS SEPARATED BY COMMAS)"
530  INPUT X,Y,Z
540  PRINT "THE RADIUS VECTOR EQUALS"SQR(X^2+Y^2+Z^2)
550  PRINT 
569  PRINT 
570  PRINT 
580  PRINT 
590  PRINT "NOW, IF YOU HAVE A NUMBER OF VALUES TO COMPUTE AND WANT"
600  PRINT "TO AUTOMATICALLY REPEAT A PORTION OF YOUR PROGRAM YOU"
610  PRINT "CAN DO THIS BY USING THIS STATEMENT:"
620  PRINT 
630  PRINT "35 GO TO 9"
640  PRINT 
650  PRINT "THIS WILL CAUSE THE COMPUTER TO RETURN TO THE BEGINNING AND"
660  PRINT "REPEAT AS LONG AS YOU HAVE VALUES OF X, Y, AND Z TO TYPE IN."
670  PRINT "DEPRESSING THE KEY MARKED 'CTRL' AND STRIKING THE KEY MARKED"
675  PRINT "'C' WILL HALT THE PROGRAM WHEN YOU ARE OUT OF VALUES FOR IT."
680  PRINT "  A FEW FINAL ITEMS AND I'LL TURN YOU LOOSE TO TRY YOUR OWN"
690  PRINT "HAND AT WRITING A PROGRAM. WHENEVER YOU START WRITING A"
700  PRINT "NEW PROGRAM,  YOU TELL THE COMPUTER BY TYPING 'SCRATCH'."
710  PRINT "YOU CAN NAME A PROGRAM FOR FUTURE REFERENCE BY TYPING"
720  PRINT "'NAME-(NAME)'. UP TO SIX LETTERS OR NUMBERS CAN BE USED"
730  PRINT "FOR THE PROGRAM NAME. IF YOU WANT THE COMPUTER TO SAVE IT"
740  PRINT "FOR YOU, SIMPLY TYPE THE WORD:"
750  PRINT 
760  PRINT "SAVE"
770  PRINT 
780  PRINT "THE COMPUTER WILL SAVE THE PROGRAM UNDER YOUR USER NUMBER"
790  PRINT "AND YOU CAN RECALL IT LATER BY TYPING 'GET-(NAME)'. IF YOU"
800  PRINT "FORGET THE NAME OF THE PROGRAM, TYPE 'CATALOG' AND THE COM-"
810  PRINT "PUTER WILL LIST THE PROGRAMS SAVED UNDER YOUR USER NUMBER."
820  PRINT "IF YOU WANT TO REMOVE A PROGRAM FROM YOUR LIBRARY, SIMPLY"
830  PRINT "TYPE 'KILL-(NAME)' AND THE PROGRAM WILL BE ERASED."
840  PRINT 
850  PRINT "WHEN YOU WANT TO SIGN OFF, TYPE 'BYE' AND THE COMPUTER WILL"
860  PRINT "LOG YOU OFF."
870  PRINT 
880  PRINT "  YOU HAVE COMPLETED ANOTHER LESSON WITH YOUR COMPUTER TUTOR"
890  PRINT "AND ARE READY TO TRY A FEW THINGS ON YOUR OWN."
900  PRINT "  THE BEST WAY TO BECOME COMFORTABLE WITH THE SYSTEM"
910  PRINT "IS TO TRY IT ON SOME OF YOUR OWN PROBLEMS. DON'T HESITATE"
920  PRINT "TO CALL ON YOUR H-P REPRESENTATIVE FOR ANY ASSISTANCE YOU"
930  PRINT "MIGHT REQUIRE."
940  PRINT "INCIDENTALLY, YOU CAN TYPE 'LIBRARY' FOR A LISTING OF COMMON"
950  PRINT "USER PROGRAMS (MATH, ENGINEERING, STATISTICS, ETC.), INFORMATIVE"
960  PRINT "LISTINGS, AND MORE TUTORIAL MATERIALS."
970  PRINT 
980  PRINT "WHEN YOU'RE READY FOR YOUR NEXT LESSON, TYPE 'GET-$TUT03',"
990  PRINT "AND WHEN THE COMPUTER RESPONDS WITH A LINE FEED, TYPE 'RUN'."
999  END 
