Commodore Business Machines PET 2001 (EN)

Table of Contents CONGRATULATIONS 1 UNPACKING YOUR PET AND TURNING IT ON 1 TOURING THE KEYBOARD 2 Figure 1. The keyboard 3 Figure 2. The characters without shifting 3 Figure 3. The characters with the SHIFT key in use 4 Exercise I - Testing the keyboard 4 Exercise 2 - Using the cursor (... and introduction to screen editing) 6 Exercise 3 - Using graphics 7 Figure 4. Rocket drawing using the graphics keys 7 Figure 5.

Graphics keys used to draw rocket 8 Exercise 4 - Creating a program 8 Exercise 5 - Listing and running your program 10 Exercise 6 - A mending the program 10 Exercise 7 - Screen editing 12 Exercise 8 - Using the reverse field 15 Exercise 9 - Programming cursor movement 16 EDITING; A REVIEW 17 Direct Cursor Control 17 Programmed Cursor Control 19 Programmed Edit Functions 20 EXPLORING BASIC 21 Exercise 10 - Printing on the screen 22 Exercise I1 - Using the built-in clock 22 Exercise 12 - Setting the clock 23 Exercise 13 - Solving mathematical problems 23 Exercise 14 - Animating your PET 30 www.commodore.ca Free for personal use but you must have written permission to reproduce

Стр. 2

Congratulations ... We congratulate you on your purchase of a Commodore PET com- puter and welcome you to the growing legion of PET users. USING YOUR CASSETTE TO SAVE A PROGRAM 31 USING YOUR CASSETTE TO LOAD A PROGRAM 33 The number of applications for the PET is as great as your imagina- tion and the number of programs available. We shall attempt, in this modest booklet, to introduce you to the art of doing your own programming and to the PET method of using prepared programs. I . Error messages 36 2. Basic commands 40 String functions 43 Arithmetic functions 44 Special symbols, commands and statements 45 I/O Commands 46 3. Special keys 46 4. Cleaning Your PET 47 5.

Cleaning and demagnetizing your tape deck head 48 Figure 6. Cassette deck head area 49 6. References 49 APPENDIX We do recommend you to the brief bibliography in this booklet's appendix. Enjoy learning about your PET and the world of com- puters as much as this booklet's authors did. By the time you're through with this booklet you should be on your way to enjoying and using your PET to its fullest. Unpacking your PET and turning it on Please check the carton for any special unpacking instructions. And examine carefully , your P17 for any concealed damage. If there is any, report this IMMEDIA TELY to both ('commodore (or your dealer) and to the shipping agent.

Remove your PET from its protective shipping carton, and place it on the counter, desk or other suitable surface, then plug it into any standard, grounded electrical outlet. Push the rocker switch, in the lower left rear where the line cord enters the unit, to the power-on position. Momentarily you may be able to see that the PET television display contains a collection of random letters and symbols. This is normal. On "Power up," PET's electrical circuits have to wake up slowly before they can function and clear the screen. Almost as fast as you can blink an eye, the screen will clear and one of the two messages below will be printed out in white letters on the black screen.

The second line of the message will vary depending on www.commodore.ca Free for personal use but you must have written permission to reproduce

Стр. 3

which memory option of PET you are using. It tells you how much memory space is free for you to use. 4k power-on display 8k power - -on display (A byte is the fundamental data element of the PET computer and corresponds roughly to one letter or digit of information. For the curious: the 4k model should show - in theory - ''4096 bytes" and the 8k, "8192 bytes. "But a few hundred are used' by the PET internally. The balance shown "3071 and "7167" are net available bytes.) Figure 1. The keyboard On most typewriters, if you strike a letter key, without shifting, you will get a lower case letter. On your PET, if you press a letter key without shifting, you will get the capital letter.

(See Figure 2.) If you fail to get the power-up display the first time, try turning the power switch slowly off then back on. Rarely will PET fail to respond to this, but if it does. turn to the Hints if You Have a Problem section at the back of this pamphlet. Most noticeable in the display is a flashing white square called a cursor. Whenever PET is waiting for some keyboard information, the cursor will begin blinking and this is where the next charac- ter will appear if it is typed in. Touring the keyboard But, before you can speak to your PET, we need to take a brief tour of the keyboard. Figure 2.

The characters without shifting Each key has a thin, transparent plastic film covering the keytop which should be removed. This protection was left in place to protect the keys against scratches during shipping. To remove the film, carefully peel off with your fingernail. If, on the other hand, you simultaneously press the shift key and a letter key, you will get the particular graphic that appears above the letter: (See Figure 3.) Key top legends bear much resemblance to those of a standard typewriter keyboard, but there are a few differences. The graphics characters are a special set of symbols unique to PET.

They are used to draw pictures and lines on the screen and to perform simple animation. The graphics can be printed on the screen just like any other letter or digit. The letters are all in virtually the same place as on a standard typewriter keyboard, but, for your convenience in numerical computations, the numbers are separate and laid out very much like a calculator keyboard. (See Figure 1.) For now, locate the L key and press it a number of times to get a 2 key. If you did, you'd get L .) I SHIFT 3 row of characters-AAAAA -on the screen. (Do riot use the

Стр. 4

key in use Next, press the I key labeled on the keyboard illustration (above). Type a different letter. Then press see the character erase? again. Did you the key to erase the last character typed, as we explained earlier. But what if you typed something wrong at the beginning of the line? You could delete characters back to that point, then retype. (P' to again. without shifting, you're getting DELETE. Shifting would get you INSERT.) Play a little game where you type in more letters and DELETE them too. But there is an easier way: PET has a feature called screen edit which allows you to move the cursor to any position on the line and at that point either insert, delete, or retype.

Remember that no matter what key you press, there is no way to damage the insides of your PET by normal keyboard operation. (Of course, PET is not intended to survive hard falls or attacks with sharp objects - but with normal care it will give you years of service.) Do not ever be afraid to experiment. (The movement of the cursor is non-destructive to the charac ters over which it passes. The characters will not be deleted or changed as you more the cursor around on the screen.) Test out the keyboard by trying the following sequence of key- strokes. Don't worry about making typing mistakes; you already know how to correct them. Locate this row of keys on top of the right hand numeric keypad.

Exercise 1 - Testing the keyboard These are all double function keys, their action depending on whether or not a I SHIFT] key is used. Press the labeled CLR The RETURN] key is a special signal to PET that you have finished typing a line and it should do something with it. This feature allows you to edit the line and get it correctly typed before your PET can act on it. HOME key top. See the cursor move to the top left corner of the screen'? This is the "HOME" position. The important thing about this exercise is to get the following dis- play on the screen after you've done: 1 4 5 www.commodore.ca Free for personal use but you must have written permission to reproduce

Стр. 5