IS-BASIC
{{language|IS-BASIC |exec=interpreted}} {{implementation|BASIC}}
IS-BASIC is the dialect of BASIC resident in ROM on the [[wp:Enterprise_(computer)|Enterprise-64 and Enterprise-128 home computer]]. It was developed by Intelligent Software in 1984. IS-Basic adheres to the ANSI BASIC standard. It is a fully structured language whose wide set of control structures includes multi-line IF...THEN...ELSE, SELECT...CASE, DO...LOOP with WHILE and UNTIL conditions at the begin and/or end of the loop and EXIT LOOP statement. Procedures and functions can have both reference and value parameters, and local variables. Errors and other exceptions are handled with exception handlers. IS-Basic has the unique ability to run multiple programs simultaneously in memory. Each program has a separate set of global variables and line numbers, but the CHAIN statement makes it possible to call one program from another and pass parameters between them. Peripherals can be controlled directly from BASIC, so there is rarely a need to use POKE and PEEK statements. IS-Basic has the usual commands for drawing dots, lines, circles and ellipses and for filling areas, and supports Logo-style turtle graphics. Sound commands can be entered into a queue, and executed in the background while the program execution continues.