The state of the key is temporarily reversed when a key is pressed: if the numeric keypad is in cursor control mode then holding down a key will place it in numeric mode, and vice versa. Num Lock Shift Shift Control and Alt keys Typing a key while the key is depressed will generate the ASCII code of that key, minus 64, thus providing a Control code between 0 and 31 (for programmers, bits 5, 6 and 7 are zero). Many key combinations are used by the line editor, and the full screen editor. A control key combination, such as , is often shown as ^C , in manuals and books that can not show the actual key. We show it that way in many manuals for reasons of space.
Ctrl Ctrl Ctrl C You don’t really need to know, for the purposes of this chapter, what each key produces. For example, ^ (the shifted 6) generates ASCII code 30, while @(theshifted2) generatesASCIIcode 0. Later,whenyoulearnprogramming, you will want to know these sorts of key equivalents (the Applix will produce a list of equivalents for you when you type the command ascii ). Ctrl Ctrl Typing a key while the key is depressed will generate the ASCII code of the key, plus 128 (for programmers, bit 7 is set by the key). Special exceptions to this rule of thumb are listed below.
Alt Alt All 256 characters of the extended ASCII character set can be produced by holding down the key and typing the character’s ASCII code (including leading zeros) on the numeric keypad section of the keyboard. This does not depend upon the state of the key. The ASCII character set is explained in detail in many elementary programming texts. It is simply a method by which the computer keeps track of the meanings of characters. You can see an ASCII table on the 1616 by typing the inbuilt command ascii (upper or lower case is fine, and don’t forget to press after the command). Alt Num Lock Enter The Alt key A few special functions are implemented using the keyboard’s key:
Alt Alt T Typing this sequence at any time switches the cassette relay to the opposite state. Do not type this during cassette I/O! When the cassette relay is connected to a cassette recorder remote control, it switches the motor on and off. Alt Ctrl R Alt Ctrl R This sequence is typed by holding down the key, then holding down the key, then the key. The effect is the same as pressing the 1616’s reset switch. This key sequence will have no effect if the 1616 has seriously hung up for some reason - you will then have to use the reset switch. This is used if the 1616 fails to respond due to a program failure, and you can not regain control in any other manner.
First Steps User Tutorial Manual Page 17