13 RETURN This key is the most commonly used key on the keyboard. When a command or anything else is typed in, it is not usually acted upon until the RETURN key is pressed. In other words, this key informs the computer that you have finished entering a line or a reply. Until you press RETURN , you can add to or delete what you have typed in. CURSOR control keys These enable you to move the flashing cursor around the screen when editing a program. Pressing any of them makes the computer automatically enter the ‘editing mode’ during which two cursors are shown on the screen (see chapter 4). DELETE Pressing this key will cause the last character typed in to be erased from the screen.
If held down, it will then erase further characters until released. COPY This key, used in conjunction with the cursor control keys, enables anything on the screen to be copied – a useful feature when editing a line in a program. ESCAPE This key is usually used to stop a program which is running. However, it can be programmed to do other things when pressed – such as moving you from one part of a program to another. BREAK This key stops the computer no matter what it is doing. The computer forgets almost everything that it has been set to do. Pressing BREAK also resets the screen to MODE 7 . Do not get into the habit of using BREAK .
The ESCAPE key provides a much less violent way of escaping from a program! (See chapter 25 for more details on BREAK ).