RD THIS IS A COURSE TO TEACH YOU TO PROGRAM THE BURROUGHS 00000100 B-5500 IN ONE OF THE LANGUAGES IT IS ABLE TO COMPREHEND. 00000200 THIS LANGUAGE IS CALLED ALGOL. DEPRESS THE LEFT ARROW 00000300 TO CONTINUE. 00000400 QU IS THIS THE COURSE YOU WANT TO TAKE. TYPE YES OR NO. 00000500 CA YES 00000600 TY VERY WELL. YOU ARE A GLUTTON FOR PUNISHMENT BUT WE WILL 00000700 TRY TO MAKE IT EASY. 00000800 WA NO 00000900 TY YOU MADE A WISE CHOICE 00001000 BR QUIT 0000003F00001100 UN PLEASE ANSWER YES OR NO 00001200 RD THIS COURSE WILL BE AN ATTEMPT TO TEACH YOU BY EXAMPLE. 00001300 EACH LESSON WILL CONSIST OF AN EXAMPLE FOLLOWED BY A 00001400 DISCUSSION OF THE EXAMPLE, QUESTIONS ABOUT THE EXAMPLE, 00001500 A HOMEWORK PROBLEM TO DO WHICH YOU ARE EXPECTED TO 00001600 WRITE AND SUBMIT TO THE COMPUTER TO RUN. THIS WILL BE 00001700 FOLLOWED BY THE LESSON NAME FOR YOUR NEXT SITTING AT 00001800 THIS CONSOLE. AFTER RUNNING YOUR PROBLEM AND GETTING 00001900 THE RESULTS BACK YOU WILL RETURN TO THE CONSOLE AND 00002000 CALL OUT THE LESSON PREVIOUSLY GIVEN YOU. THE LESSON 00002100 WILL ASK YOU QUESTIONS ABOUT THE RESULTS YOU OBTAINED 00002200 AND THEN GO ON TO THE NEXT EXAMPLE IF YOU WORKED THE 00002300 PREVIOUS ONE CORRECTLY. DEPRESS THE LEFT ARROW TO 00002400 CONTINUE THE LESSON WITH THE FIRST EXAMPLE. 00002500 RD ......................................................... 00002600 00002700 BEGIN 00002800 COMMENT THIS IS EXAMPLE 1; 00002900 FILE IN CARD (2,10); 00003000 FILE OUT LINE 4(2,15); 00003100 FORMAT F1 (3F12.6); 00003200 FORMAT F2 (4F12.6); 00003300 FORMAT F3 ("PROBLEM NUMBER 1 RESULTS"); 00003400 LABEL EOF,RETURN; 00003500 REAL A,B,C,SUM; 00003600 WRITE (LINE,F3); 00003700 RETURN: READ (CARD,F1,A,B,C)[EOF]; 00003800 SUM := A + B+ C; 00003900 WRITE (LINE,F2,A,B,C,SUM); 00004000 GO TO RETURN; 00004100 EOF: END. 00004200 00004300 ................................................................... 00004400 THE ABOVE IS A PROGRAM. READ IT AND WHEN YOU ARE READY 00004500 DEPRESS THE LEFT ARROW. 00004600 QU EXAMPLE 1 IS AN ALGOL PROGRAM. YOU WILL NOTICE THAT IT 00004700 STARTS WITH A BEGIN AND ENDS WITH AN END FOLLOWED 00004800 BY WHAT CHARACTER. 00004900 CA PERIOD 00005000 CB . 00005100 TY CORRECT. ALL PROGRAMS START WITH A BEGIN AND END WITH A 00005200 END FOLLOWED BY A PERIOD. 00005300 UN PLEASE LOOK AT THE EXAMPLE CLOSELY AND TRY AGAIN. 00005400 QU YOU WILL ALSO NOTICE THAT BLANKS ARE NOT VERY IMPORTANT. 00005500 THERE CAN BE ANY NUMBER OF BLANKS BETWEEN CHARACTERS OR 00005600 WORDS. WHAT IS THE MINIMUM NUMBER OF BLANKS BETWEEN TWO 00005700 WORDS. 00005800 CA ONE 00005900 CB 1 00006000 TY CORRECT. THERE CAN BE MORE THAN ONE HOWEVER IF THERE 00006100 WERE LESS THAN ONE THERE WOULD NOT BE TWO WORDS BUT ONE. 00006200 WA ZERO 00006300 WB 0 00006400 TY HOW COULD THERE BE NO BLANKS BETWEEN TWO WORDS. PLEASE 00006500 TRY AGAIN. 00006600 UN THINK ABOUT IT... TRY AGAIN. 00006700 QU NOT CONSIDERING THE BEGIN AND END THERE ARE TWO TYPES OF 00006800 ENTRIES - DECLARATIONS AND STATEMENTS. DECLARATIONS ARE 00006900 TO DECLARE IDENTIFIERS. FOR EXAMPLE FILE IN DECLARES 00007000 AN IDENTIFIER CARD. WHAT DOES FILE OUT DECLARE. 00007100 CA LINE 00007200 CB THE IDENTIFIER LINE 00007300 CB IDENTIFIER LINE 00007400 TY VERY GOOD. 00007500 WA IDENTIFIER 00007600 TY WHAT IDENTIFIER. 00007700 UN TRY AGAIN. 00007800 QU NOTE THAT THE DECLARATOR LABEL DECLARES TWO IDENTIFIERS, 00007900 NAMELY EOF AND RETURN TO BE LABEL IDENTIFIERS. THIS 00008000 REQUIRES THE USE OF ONY ONE DECLARATION, THE IDENTIFIERS 00008100 BEING SEPARATED BY WHAT. 00008200 CA COMMA 00008300 CB , 00008400 TY CORRECT. YOU ARE VERY OBSERVANT. 00008500 UN LOOK AT THE EXAMPLE AND TRY AGAIN. 00008600 QU REAL IS A DECLARATOR FOR IDENTIFIERS WHICH ARE TO BE 00008700 REAL NUMBERS - AS OPPOSED TO INTEGERS OR OTHER TYPES OF 00008800 NUMBERS YOU WILL BE EXPOSED TO LATER. HOW MANY REAL 00008900 IDENTIFIERS ARE DECLARED ON THIS LINE. 00009000 CA FOUR 00009100 CB 4 00009200 TY VERY GOOD. 00009300 UN LOOK AT THE EXAMPLE AND TRY AGAIN 00009400 QU AT THE END OF EACH LINE IS A SPECIAL CHARACTER. 00009500 WHAT IS IT. 00009600 CA SEMICOLON 00009700 CB ; 00009800 TY CORRECT. JUST AS COMMAS SEPARATE IDENTIFIERS IN A SINGLE 00009900 DECLARATION, SEMICOLONS SEPARATE DECLARATORS FROM EACH 00010000 OTHER. 00010100 UN LOOK AT THE EXAMPLE. WHAT IS AT THE END OF EACH LINE. 00010200 RD IN MAKING UP THE NAMES OF IDENTIFIERS, THERE ARE TWO 00010300 RULES TO BE FOLLOWED: 00010400 1. THE IDENTIFIER CAN BE ANY WORD THAT BEGINS WITH AN 00010500 ALPHABETIC CHARACTER FOLLOWED BY ANY COMBINATION 00010600 OF ALPHABETIC OR NUMERIC CHARACTERS, AND CAN BE FROM 00010700 ONE TO SIXTY-THREE CHARACTERS LONG. 00010800 2. AN IDENTIFIER CAN NOT BE A ALGOL RESERVED WORD, SUCH 00010900 AS BEGIN,FILE,IN,OUT,LABEL,FORMAT,REAL,END, OR COMMENT. 00011000 THESE ARE THE ONLY ONES WE HAVE DISCUSSED SO FAR BUT 00011100 I WILL KEEP YOU POSTED AS WE ENCOUNTER NEW ONES. 00011200 IDENTIFIERS MUST CONFORM TO THE ABOVE RULES AND SHOULD 00011300 BE MADE UP SO THAT THE NAME MEANS SOMETHING TO YOU. 00011400 DEPRESS THE LEFT ARROW TO CONTINUE. 00011500 QU IS M A LEGAL IDENTIFIER. 00011600 CA YES 00011700 TY CORRECT. 00011800 WA NO 00011900 TY READ THE RULES ABOVE AND TRY AGAIN. 00012000 QU IS A1B3 A LEGAL IDENTIFIER. 00012100 CA YES 00012200 TY CORRECT. 00012300 WA NO 00012400 TY TRY AGAIN. 00012500 UN TRY AGAIN. 00012600 QU IS 2AB A LEGAL IDENTIFIER. 00012700 CA NO 00012800 TY CORRECT. 00012900 CA NO 00013000 WA YES 00013100 TY IDENTIFIERS START WITH A WHAT. TRY AGAIN. 00013200 UN PLEASE TRY AGAIN. 00013300 QU IS A.13C A LEGAL IDENTIFIER. 00013400 CA NO 00013500 TY CORRECT. DENTIFIERS MAY NOT CONTAIN SPECIAL CHARACTERS. 00013600 WA YES 00013700 TY WHAT ABOUT SPECIAL CHARACTERS. TRY AGAIN. 00013800 UN TRY AGAIN 00013900 QU IS SUMXY A LEGAL IDENTIFIER. 00014000 CA YES 00014100 TY CORRECT 00014200 WA NO 00014300 TY READ THE RULES AND TRY AGAIN. 00014400 UN TRY AGAIN 00014500 RD AS NOTED BEFORE THERE ARE TWO TYPES OF LINES IN AN ALGOL 00014600 PROGRAM - DECLARATIONS AND STATEMENTS. PRIOR TO THIS WE 00014700 HAD BEEN DISCUSSING DECLARATIONS - WHICH DECLARE 00014800 IDENTIFIERS AS TO WHAT THEY REPRESENT SUCH AS A FILE, 00014900 A LABEL, A FORMAT, OR A REAL NUMBER. 00015000 NOW LETS DISCUSS STATEMENTS WHICH TELL THE COMPUTER 00015100 WHAT ACTION TO TAKE WITH THE IDENTIFIERS CONTAINED IN 00015200 THE STATEMENT. 00015300 REFERING TO EXAMPLE 1 THE FIRST STATEMENT IS THE LINE 00015400 WHICH STARTS WITH THE WORD WRITE. THIS STATEMENT TELLS 00015500 THE MACHINE TO WRITE ON THE FILE CALLED LINE (PRINTER) 00015600 ACCORDING TO FORMAT F3 AND LOOKING AT FORMAT F3 WE 00015700 FIND THAT WHAT WILL PRINT IS A HEADING LINE - PROBLEM 00015800 NUMBER 1 RESULTS. 00015900 THE NEXT STATEMENT IS LABELED WITH THE LABEL RETURN 00016000 AND THE STATEMENT DIRECTS THE COMPUTER TO READ 00016100 INFORMATION FROM THE FILE CALLED CARD (CARD-READER) 00016200 ACCORDING TO FORMAT F1 AND TO READ THREE REAL 00016300 NUMBERS NAMELY A,B,AND C AND WHEN ALL THE CARDS IN THE 00016400 FILE HAVE BEEN READ DO NOT GO TO THE NEXT STATEMENT BUT 00016500 GO TO THE LABEL EOF FOR THE NEXT STATEMENT TO EXECUTE. 00016600 THE NEXT STATEMENT WILL ADD A, B, AND C AND STORE THE 00016700 RESULTING SUM INTO THE IDENTIFIER CALLED SUM. 00016800 THE NEXT STATEMENT INSTRUCTS THE MACHINE TO WRITE ON 00016900 THE FILE CALLED LINE AND ACCORDING TO FORMAT F2, THE 00017000 REAL NUMBERS A, B, C, AND THE RESULT OF THE 00017100 COMPUTATION SUM. 00017200 THE NEXT STATEMENT INSTRUCTS THE COMPUTER TO GO TO THE 00017300 LABEL RETURN FOR THE NEXT STATEMENT TO EXECUTE. 00017400 THE LAST STATEMENT CONTAINS THE LABEL EOF AND WHEN NO 00017500 MORE INPUT INFORMATION IS TO BE READ THIS STATEMENT WILL 00017600 BE EXECUTED AND THE PROGRAM WILL END. 00017700 DEPRESS THE LEFT ARROW TO CONTINUE. 00017800 QU JUST AS DECLARATIONS ARE SEPARATED FROM EACH OTHER BY A 00017900 SEMICOLON, STATEMENTS ARE SEPARATED BY A WHAT. 00018000 CA SEMICOLON 00018100 CB ; 00018200 TY CORRECT. 00018300 UN LOOK BACK AT THE EXAMPLE AND TRY AGAIN. 00018400 QU IN GOING BACK THROUGH THE EXAMPLE WE NOTE THAT NORMALLY 00018500 STATEMENTS ARE EXECUTED ONE AT A TIME IN SEQUENCE UNTIL 00018600 THAT SEQUENCE IS CHANGED BY A STATEMENT BEGINNING WITH 00018700 WHAT TWO WORDS. 00018800 CA GO TO 00018900 TY CORRECT. WE COULD THEN SAY THAT A GO TO CHANGES THE 00019000 SEQUENCE OF EXECUTION OF STATEMENTS. 00019100 WA READ 00019200 TY NOT THAT STATEMENT. TRY ANOTHER ONE. 00019300 UN LOOK AT THE EXAMPLE AND TRY AGAIN OR TRY HELP. 00019400 QU WHAT OTHER STATEMENT CHANGES THE SEQUENCE NOT ALL OF THE 00019500 TIME BUT ONLY WHEN A CERTAIN CONDITION IS ENCOUNTERED. 00019600 CA READ 00019700 CB READ STATEMENT 00019800 CB THE READ STATEMENT 00019900 TY VERY GOOD. YOU ARE READY TO RUN YOUR FIRST PROGRAM. 00020000 UN LOOK AT THE EXAMPLE AND TRY AGAIN. 00020100 RD YOU WERE GIVEN A SAMPLE PROGRAM WHEN YOU STARTED THIS 00020200 COURSE. THIS PROGRAM IS EXACTLY EXAMPLE 1. YOU 00020300 ARE TO CHANGE THIS PROGRAM SO AS TO COMPUTE SUM TO BE 00020400 A + B - C. THIS WILL REQUIRE YOU TO CHANGE ONLY ONE 00020500 CARD AND THAT CARD IN ONLY ONE COLUMN. AFTER YOU HAVE 00020600 CHANGED THE PROGRAM SUBMIT IT TO THE COMPUTER ROOM TO BE 00020700 RUN. AFTER YOU HAVE RUN THE PROGRAM AND HAVE LOOKED AT 00020800 THE RESULTS PLEASE SIGN BACK ON AND ASK FOR COURSE NAME 00020900 00021000 .......... JES2 .......... 00021100 00021200 GOOD LUCK.. I WILL TALK TO YOU LATER.. NOW PLEASE DEPRESS 00021300 THE LEFT ARROW. 00021400 LA QUIT 900021500 999999 900021600