Atari Basic Programming
Before you begin your journey into learning about Atari Basic Programming in Atari Basic, it is quite beneficial if you gather a little information that will help you write many other programs. The vision of this guide is to establish a plan to keep you on a flow with learning and absorbing.
Getting Used to the Editor
The Atari Basic Programming editor will first load up after you turn on the computer and the hardware loads the screen. You will first hear the audible greeting of the booting process, and eventually you will see a READY prompt surrounded by an ocean blue screen.
This is the editor. You will learn how how to interact with Basic through commands issued on the keyboard as words and eventually full statements.
There are several things to note. Pressing down a key will repeat that key in succession until you release it. Holding down the control key and pressing on the arrows will allow the cursor to be moved around. This will be handy later when you need to edit a program line.
Atari Control Key
Pressing the control key and the clear key at the same time will erase all of the text on the screen and put the cursor at the top.
Type some characters, words, or your name on the screen. By keeping the control and insert key when to the left of the text, you can insert the lines over. Likewise in reverse motion, holding down the control key and the delete key will pull the text back in a motion and when it reaches the cursor position it will be erased. Delete pressed by itself will remove any text characters from the left.
The TAB key can be used to quickly relocate the cursor on the screen. Atari Basic also provides the ability to mark a tab location by holding down the Shift key and pressing the TAB key.
Atari Inverse Key
Another interesting aspect is the key located at the bottom, right of the keyboard. This is known as the inverse key. It will reverse the color of text characters. So when you type, you will see a shadow display surrounding the characters, which appears as a white background. Press the inverse key again to turn off this mode.
Notice the Esc key located at the upper left corner. This is the escape key. Pressing this key twice will produce the escape symbol.
Another key of value is the break key, situated at the top right of the keyboard. It is used to interrupt a line and send the cursor to a new line. If you typing in a program, it homes the cursor to the far left. Later you will use the break key to exit a program that is running.
As you are typing in commands and words in the editor you are using what is known as the immediate mode. This means that as soon as you press Return after a command, it executes instantly. Let’s try some example commands. First we will explore some commands that help you clear memory and show a listing on a screen.
So to get a fresh start and clear everything in your Atari Basic computer’s memory, type the command NEW and press the Return key. This will be a common practice style you will use again and again.
Atari Basic Programming Example
Let’s use an example from the Atari 65xe Personal Computer Owner’s Manual. Type the Atari Basic Programming line below. When you are finished, press the Return key. This will record it in the computer’s memory. You will not see anything happen on the screen yet.
10 PRINT “I HEARD OF A POET NAMED SAM”
The number you have typed in front of this command sequence has entered this in Basic’s RAM memory.
When you begin to type on the screen, when entering a program line, you will see the cursor return to the far left and down one line each time. This conveniently provides room for more data that is appended to the same numbered line (known as a statement).
Executing a Basic Program
Let’s finally see what this line number does. On a new line, enter the command RUN and press the Return key.
If you made no mistakes when entering the statement, you should see the cursor move down one line and display thew words below on your screen.
I HEARD OF A POET NAMED SAM
Atari Basic has just executed your very first program. Now let’s add some more lines below and RUN it when we are done.
15 PRINT “WHOSE POEMS WERE THE TALK OF THE LAND.”
20 PRINT “I MET HIM ONE DAY, AND TO MY DISPMAY,”
30 PRINT “HIS BRAINS WERE SILICON-SAND.”
`40 PRINT “AYE SAY HYE; U SAY BI.”
50 PRINT “I SAY HI; YOU SAY BYE.”
70 PRINT “THAT RAN FROM DUSK UNTIL DAWN.”
80 PRINT “IT WOULDN’T RESPOND TO ESCAPE, BREAK, CONTROL, OR LIST, AND IT WAS STILL RUNNING WHEN I TURNED OFF THE SWITCH.”