TURBO-LESSONS - A Pascal Tutorial Version 1.01 Page 1 TURBO-LESSONS A TURBO Pascal Tutorial Version 1.01 by Lyle M. Faurot June 8, 1985 Copyright (C), 1985 by Lyle Faurot. All rights reserved. TURBO is a trademark of Borland International. Œ TURBO-LESSONS - A Pascal Tutorial Version 1.01 Page 2 T A B L E O F C O N T E N T S Page Introduction . . . . . . . . . . . . . . . . . . . . . . . 4 Distribution Notice . . . . . . . . . . . . . . . . . . . 5 TURBO-LESSON 1: GETTING STARTED Loading TURBO . . . . . . . . . . . . . . . . . . . . 5 Main Menu . . . . . . . . . . . . . . . . . . . . . . 5 TURBO-LESSON 2: EDITING PROGRAMS Starting an edit session . . . . . . . . . . . . . . 10 Ending an edit session . . . . . . . . . . . . . . . 11 Moving the cursor . . . . . . . . . . . . . . . . . . PROG2 Inserting/Replacing text . . . . . . . . . . . . . . PROG2 Deleting text . . . . . . . . . . . . . . . . . . . . PROG2 Auto-tabbing . . . . . . . . . . . . . . . . . . . . PROG2 TURBO-LESSON 3: PROGRAM STRUCTURE Program structure . . . . . . . . . . . . . . . . . . 12 Compiler Directive, $U+ . . . . . . . . . . . . . . . 13 WRITE and WRITELN statements . . . . . . . . . . . . 13 Comments . . . . . . . . . . . . . . . . . . . . . . 14 TURBO-LESSON 4: DECLARATIONS, INPUT DECLARATIONS part of program . . . . . . . . . . . . 16 VAR declaration . . . . . . . . . . . . . . . . . . . 16 Input usint READLN statement . . . . . . . . . . . . 17 Integer Variables . . . . . . . . . . . . . . . . . . 18 TURBO-LESSON 5: INTEGER EXPRESSIONS Assignment statements . . . . . . . . . . . . . . . . 20 Integer expressions . . . . . . . . . . . . . . . . . 21 Problems with expressions . . . . . . . . . . . . . . 23 TURBO-LESSON 6: CONDITIONAL PROCESSING Selection structures . . . . . . . . . . . . . . . . 25 IF statement (One-way selection) . . . . . . . . . . 26 IF statement (Two-way selection) . . . . . . . . . . 27 TURBO-LESSON 7: REPEAT STATEMENT CHARacter variables . . . . . . . . . . . . . . . . . 28 BOOLEAN variables . . . . . . . . . . . . . . . . . . 29 REPEAT statement . . . . . . . . . . . . . . . . . . 30 TURBO-LESSON 8: CASE STATEMENT Block statements . . . . . . . . . . . . . . . . . . 32 CASE statement . . . . . . . . . . . . . . . . . . . 34 TURBO-LESSON 9: FOR STATEMENT Print field width indicator, ":n" . . . . . . . . . . 36 FOR statement . . . . . . . . . . . . . . . . . . . . 37 TURBO-LESSON 10: WHILE STATEMENT CONSTant declaration . . . . . . . . . . . . . . . . 38 WHILE statement . . . . . . . . . . . . . . . . . . . 39 Delay timing loop . . . . . . . . . . . . . . . . . . 41 Œ TURBO-LESSONS - A Pascal Tutorial Version 1.01 Page 3 INTRODUCTION TO TURBO-LESSONS When Borland International ran their first ads for TURBO PASCAL my reaction was "You gotta be kidding - they can't do that". But, it seems they did! I've been enjoying this programming system ever since. Apparently a great many other programmers are either programming in TURBO or would like to learn how. TURBO-LESSONS were designed to meet that need. Each TURBO-LESSON is a bite-size tutorial which introduces one or more new concepts. Each of the lessons are presented in the same format which includes the OBJECTIVES of the lesson, and the TUTORIAL portion of the lesson. Most lessons direct you to work with a sample program which is provided with these lessons. Be sure you make a back-up copy of the programs - you will be modifying and adding to the sample programs, and may want to return to the original copy of a program. Sample programs are numbered to correspond to the lessons: PROG1 goes with TURBO-LESSON 1, PROG2, PROG2A go with TURBO- LESSON2, . . . To begin, you should print the TURBO-LESSONS before loading TURBO. To help you get started, TURBO-LESSON 1 shows you how to load TURBO and run a sample program. **************************************** D I S T R I B U T I O N N O T I C E **************************************** TURBO-LESSONS are being distributed as USER-SUPPORTED software. Suggested donation, $7.00, for this first set, lessons 1-10, may be sent to: Dr. Lyle Faurot 1904 18th Ave. South Moorhead, MN 56560 COPYING BY ORGANIZATIONS Clubs and other non-profit organizations may copy these lessons for their members, with the following conditions: 1. No charge is made for TURBO-LESSONS, except a distribution charge may be made to cover the price of the diskette. Suggested donation is to be made directly to the author of the lessons. 2. Club members are informed that TURBO-LESSONS are distributed as user-supported software. 3. TURBO-LESSONS are distributed unmodified. Œ TURBO-LESSONS - A Pascal Tutorial Version 1.01 Page 4 TURBO-LESSON 1: GETTING STARTED OBJECTIVES - In this lesson you will learn about: 1. Loading TURBO 2. Using the Main Menu to Load, Compile, and Run a program INTRODUCTION TURBO-LESSONS were written with the following goals in mind: -- Present the concepts of Pascal and the TURBO Pascal implementation in bite-size chunks (called lessons). -- Provide one or more sample Pascal programs with each lesson. Programming examples are often more helpful than eloquent discussion in learning to program. -- Structure the lessons in a parallel format to make them more useful later as a reference. The OBJECTIVE section at the beginning of each lesson will help you locate a topic later. -- Structure the lessons in an Action format. If you are like me, you probably learn programming best by doing. -- Mark the points where some action is suggested. This should allow for differences in learning styles. The action points are marked as follows: ##### DO: For those who like to hit the high points as fast as possible, these action markers will point the way. Now, without further delay, on with the show! Œ TURBO-LESSONS - A Pascal Tutorial Version 1.01 Page 5 1. Loading TURBO. To get started, put a diskette with TURBO PASCAL in your default drive. ##### DO: Type TURBO and enter. A message will appear: Include error messages (Y/N)? You should answer Y to provide on-screen error messages. The Main Menu will appear at this point. 2. Using the Main Menu to Load, Compile, and Run a program. The menu should appear with one letter of each option highlighted. ##### DO: Adjust the brightness level of your screen. You may need to adjust both brightness and contrast to make the key letters stand out at a comfortable level. The main menu is the starting point for most of the things you will do with TURBO. Some of the options will be discussed in more detail later, but for now, you should learn to get back to the main menu from each of the options. ******************** Logged drive: The Logged drive is where your Work files are stored. This option is used to change your logged drive. ##### DO: Type L. Computer responds: "New drive:" Type B (or another drive) and enter. Look at the top of the screen. Did the logged drive change? Now, depress the space bar. It appeared that no change had been made until the menu screen was redisplayed. Œ TURBO-LESSONS - A Pascal Tutorial Version 1.01 Page 6 ******* NOTE: SOME OF THE OPTIONS DO NOT UPDATE THE MENU SCREEN. YOU CAN REDISPLAY THE MENU WITH THE SPACE BAR OR ENTER KEY. You could have responded to the "New drive:" message by depressing the enter key without entering another drive designator. The enter key by itself is used to escape from this option without making any changes. The first four options at the top of the menu, L, A, W, and M all use the enter key alone as an escape key. ******************** Active directory: \ Use the A option to change the Active subdirectory if your logged drive is a hard disk. ##### DO: Type A. Computer responds: "New directory:" Type subdirectory name and enter or just enter for no change. ******************** Work file: This is where you name your work file. The work file will hold the PASCAL program you are writing or editing. ##### DO: Type W. Computer responds: "Work file name:" Type PROG1 and enter. (If you get the message, "New File", PROG1.PAS was not found on your logged drive. Your sample programs, including PROG1, should be on the logged drive). ******************** Main file: Ignore this option for now. If you just can't resist typing M at this point, remember that Enter is the escape key for this option. Œ TURBO-LESSONS - A Pascal Tutorial Version 1.01 Page 7 ******************** Run This option is used to execute a program, compiling it first, if necessary. ##### DO: Type R. The program in your work file, PROG1, is compiled and executed. Type R again. Note that the program runs again without compiling. The Run option will only compile if changes have been made in the program since the previous compile. Depress the space bar to get the menu back. ******************** Compile The program may be compiled without executing by using the C option. You may want to compile to see an error message without running the program. Or you may be compiling a COM file, which cannot be executed until you exit TURBO to DOS. ##### DO: Type C. The program compiles but doesn't run. Use this option when you want to compile without executing the program immediately. ******************** Edit The editor is used to enter a new program or change a program. Another lesson is devoted to editing. For now, you should find out how to get back to the menu from this option. ##### DO: Type E. The program, PROG1, appears on the screen, ready to edit. Use the Ctrl-K, Ctrl-D sequence to return to the main menu. Œ TURBO-LESSONS - A Pascal Tutorial Version 1.01 Page 8 ##### DO: Type Ctrl-K, Ctrl-D. (While depressing the Ctrl key, type K followed by D.) The main menu reappears. Note that there is no way to abandon the edited file in memory. This is not so bad since the edited copy of the program in memory is not automatically saved to disk. You can use the Work file option to get another copy of the program from disk. ******************** Save Use this option to copy your current work file from memory to disk. ##### DO: Type S. The program, PROG1, is saved to the disk on the drive designated when you named this work file. Since the work file is not automatically saved to disk, TURBO reminds you to save the file before any option which would destroy the copy of the file in memory. NOTE: REMEMBER, IT IS UP TO YOU TO SAVE YOUR WORK FILE. IT'S A GOOD IDEA TO SAVE IT FREQUENTLY, IN CASE SOMETHING SUCH AS AN INFINITE LOOP FORCES YOU TO RE-BOOT (IN WHICH CASE YOUR WORK FILE IN MEMORY WOULD BE FOREVER GONE!) ******************** Dir The D option works similar to DIR in DOS. ##### DO: Type D. Computer responds: "Dir mask:" Depress the Enter key to get a directory of the logged drive or use drive designator to get a directory of another drive. You can use the wildcards, "*" and "?". Œ TURBO-LESSONS - A Pascal Tutorial Version 1.01 Page 9 ******************** compiler Options These will be discussed later when they are needed. Try the O option now to be sure you know how to get back to the menu. ##### DO: Type O. The compiler Options menu is displayed. You can choose the various compiler options by typing the corresponding letter. ##### DO: Type C. Notice the arrow moved to a different option. Type H. Type M. Be sure to leave the compiler option set to M, memory before returning to the main menu. Type Q. The main menu reappears. ******************** Quit This option returns you to DOS. When you are through experimenting with the menu options, ##### DO: Type Q. You will be prompted to save your work file if it has been modified since you last saved it. The prompt of the default drive will be displayed. Œ