100' NAME--BASICT 110' 120' DESCRIPTION--FIRST PROGRAM IN A SEQUENCE THAT TEACHES 130' THE BASIC LANGUAGE. 140' 150' SOURCE--UNKNOWN 160' 170' INSTRUCTIONS--TYPE "RUN" AND FOLLOW INSTRUCTIONS. 180' 190' 200' * * * * * MAIN PROGRAM * * * * * * * * * * * 210' 220 PRINT" ***PREFACE***" 230 PRINT 240 PRINT 250 PRINT" SECTIONS OF THE FOLLOWING PROGRAM ARE NOW AVAILABLE IN " 260 PRINT"A BOOKLET ENTITLED *BEGINNING BASIC*. DO YOU HAVE A COPY?" 270 PRINT"ANSWER THE QUESTION YES OR NO AND PRESS THE (RETURN KEY)"; 280 INPUT A$ 290 IF A$ = "YES" THEN 430 300 PRINT"" 310 PRINT" YOU SHOULD TYPE NO WHENEVER THE MACHINE ASKS YOU IF YOU" 320 PRINT"HAVE A BOOKLET. THE MACHINE WILL THEN PRINT OUT EXACTLY" 330 PRINT"WHAT IS IN THE BOOKLET. IN OTHER WORDS, EVERYTHING YOU NEED TO" 340 PRINT"KNOW IS AVAILABLE ON THE TELETYPE. IT JUST TAKES A FEW MINUTES" 350 PRINT"LONGER TO PRINT OUT." 360 PRINT 370 PRINT 380 PRINT" * * * * * * *" 390 PRINT 400 PRINT 410 PRINT 420 GO TO 530 430 PRINT 440 PRINT" YOU SHOULD TYPE YES WHENEVER THE MACHINE ASKS YOU IF" 450 PRINT"YOU HAVE A BOOKLET. THEN YOU SHOULD READ THE EXPLANATION" 460 PRINT"IN THE BOOKLET FOLLOWED BY THE ASSIGNMENT THAT IS" 470 PRINT"PRINTED OUT ON THE TELETYPE." 480 PRINT 490 PRINT" NOW READ YOUR FIRST EXPLANATION AND DO YOUR FIRST ASSIGNMENT." 500 PRINT"BE SURE TO READ *THINGS TO KEEP IN MIND WHILE WRITING A PROGRAM*" 510 PRINT"GOOD LUCK..." 520 STOP 530 PRINT " BASIC, AND THE PDP 10 TIME SHARING SYSTEM" 540 PRINT 550 PRINT " BASIC IS A VERY SIMPLE LANGUAGE FOR 'SPEAKING' TO THE" 560 PRINT"COMPUTER. THE FORMULAS FOR CARRYING OUT ALMOST ANY NUMERICAL" 570 PRINT"CALCULATION CAN BE EXPRESSED IN BASIC. THE SET OF INSTRUCTIONS" 580 PRINT "TO THE COMPUTER IS CALLED A 'PROGRAM'. THE PROGRAM CONSISTS OF" 590 PRINT "A NUMBER OF 'STATEMENTS'. THESE STATEMENTS ARE EXECUTED OR" 600 PRINT "CARRIED OUT BY THE COMPUTER ONE BY ONE, IN ORDER, AND IN MUCH" 610 PRINT "THE SAME WAY ONE FOLLOWS A RECIPE FOR BAKING A CAKE." 620 PRINT 630 PRINT " THERE ARE A NUMBER OF DIFFERENT KINDS OF BASIC STATEMENTS," 640 PRINT "ALL OF WHICH WILL BE EXPLAINED IN THE COURSE OF THESE LESSONS." 650 PRINT "WE WILL START BY EXPLAINING A SIMPLE PROGRAM BUILT AROUND" 660 PRINT "THE FOLLOWING KINDS OF STATEMENTS: LET, PRINT, AND END." 670 PRINT 680 PRINT " LET US 'WRITE' A PROGRAM FOR COMPUTING THE AVERAGE" 690 PRINT "OF THE NUMBERS 1, 2, 5, 8 AND PRINTING THE ANSWER. ONE" 700 PRINT "POSSIBLE PROGRAM MIGHT GO AS FOLLOWS:" 710 PRINT " 10 LET A = (1 + 2 + 5 + 8)/4" 720 PRINT " 20 PRINT A" 730 PRINT " 30 END" 740 PRINT 750 PRINT " NOTICE HOW THE DESIRED CALCULATION IS PERFORMED IN" 760 PRINT "STATEMENT NUMBER 10, AND THE ANSWER IS ASSIGNED TO THE " 770 PRINT "VARIABLE CALLED A. IN STATEMENT 20 THE VALUE OF A IS" 780 PRINT "PRINTED OUT. STATEMENT 30 IS AN END STATEMENT THAT TELLS THE" 790 PRINT "COMPUTER THAT THERE IS NO MORE PROGRAM." 800 PRINT 810 PRINT " YOUR FIRST ASSIGNMENT IS TO COPY THE ABOVE PROGRAM, AND" 820 PRINT "TO RUN IT AND GET THE ANSWER. YOU SHOULD PROCEED AS FOLLOWS:" 830 PRINT " 1. TYPE THE WORD NEW THEN PRESS THE (RETURN) KEY." 840 PRINT " 2. WHEN THE COMPUTER ASKS FOR THE NEW PROBLEM NAME--" 850 PRINT" TYPE THE TITLE AVRAGE AND THEN PRESS THE" 860 PRINT " (RETURN) KEY." 870 PRINT " 3. AFTER THE COMPUTER TYPES READY., SIMPLY COPY THE" 880 PRINT " PROGRAM AS IT IS GIVEN ABOVE, PRESSING THE (RETURN)" 890 PRINT " KEY AFTER EACH LINE, INCLUDING THE LAST." 900 PRINT" 4. TYPE THE WORD LIST AND (RETURN) TO SEE WHAT THE" 910 PRINT" MACHINE UNDERSTANDS YOUR PROGRAM TO BE." 920 PRINT " 5. TYPE THE WORD RUN FOLLOWED BY PRESSING" 930 PRINT " THE (RETURN) KEY." 940 PRINT " 6. IF YOU HAVE COPIED THE PROGRAM CORRECTLY, THE TELETYPE" 950 PRINT " MACHINE SHOULD PRINT OUT THE NUMBER 4 ." 960 PRINT " IF YOU HAVE MADE A MISTAKE, LOCATE THE INCORRECT" 970 PRINT " STATEMENT AND RETYPE IT JUST AS YOU SHOULD HAVE BEFORE." 980 PRINT " DO NOT, REPEAT, NOT TYPE OVER THE WHOLE PROGRAM --" 990 PRINT " ONLY THOSE STATEMENTS THAT ARE IN ERROR. AFTER YOU" 1000 PRINT " HAVE MADE THE CORRECTIONS, TYPE RUN AND" 1010 PRINT " (RETURN) AS STATED IN STEP 4. ABOVE." 1020 PRINT " 7. AFTER YOU ARE SATISFIED THAT YOU HAVE SUCCESSFULLY" 1030 PRINT " DONE THIS PROBLEM, TYPE TEST AND (RETURN)." 1040 PRINT"" 1050 PRINT 1060 PRINT" BEFORE DOING YOUR FIRST ASSIGNMENT;" 1070 PRINT 1080 PRINT" A) TYPE OLD AND HIT THE (RETURN) KEY." 1090 PRINT 1100 PRINT" B) TYPE THE OLD PROBLEM NAME THINGS*** AND (RETURN)." 1110 PRINT 1120 PRINT" C) WHEN THE MACHINE IS READY, TYPE RUN AND (RETURN)." 1130 PRINT 1140 PRINT" D) WHEN THE PRINTOUT IS FINISHED, DO STEP 1) OF YOUR" 1150 PRINT" ASSIGNMENT LISTED IN BASICT." 1160 PRINT 1170 PRINT 1180 END