override mathematical order of operation AND is used for logical 'and' operations OR is used for logical 'or' operations NOT is used for logical 'not' operations For testing, the following operators are used: = is equal to > is greater than < is less than >= is greater than or equal to (also => is acceptable) <= is less than or equal to (also =< is acceptable) <> is not equal to (also >< is acceptable) Other symbols used in BASIC: " " indicates string data is a constant (static) : separates multiple commands on a single program line A semicolon, when encountered in a PRINT function, will cause the output to remain on the same line A comma, when encountered in a PRINT function, will tab to the next column Key num indicates a numeric expression is required. This can be a fixed number, a variable, or other operation or function that returns a numeric quantity. str indicates a string expression is required. This can be a static string value (in quotes), a string variable, or other function or expression that returns a string of characters. device number indicates a device. By default, device 0 (screen and keyboard) is assumed. In Color BASIC, device #-1 (cassette) and #-2 (printer) are available to the programmer. Edit mode If you make a mistake typing in a line, you can either retype it from scratch (or DEL it).. or you can EDIT it. When in EDIT mode, you get a reprint of the line, and a second copy that you SPACEbar across chars. You cannot use arrow keys. backspace takes you left, but does not actually erase it in the buffer. 'i' puts you in insert mode. pressing return gets you out of it. 'c' changes one char, 'd' deletes one char. 'x' takes you to end of line, allowing you to e'x'tend it. 'l' redraws the line. 's' searches for the next instance of a character. For the 's', 'c' and 'd' commands you can also enter a number (#) before pressing any of them which will: 's' - search for the # instance of the character, 'c' - allow you to change # of characters, 'd' - delete # amount characters. Functions ABS(num) returns the absolute value of num ASC(str) returns the ASCII code of the first character in str CHR$(num) returns a single string character with the ASCII code