SuperBASIC

SuperBASIC is an advanced variant of the BASIC programming language developed by Sinclair Research, primarily designed by Jan Jones in the early 1980s. It was originally intended for an unreleased home computer codenamed SuperSpectrum, but it was ultimately built into the ROM firmware of the Sinclair QL microcomputer, announced in January 1984. SuperBASIC introduced structured programming features that earlier Sinclair BASIC dialects lacked, including IF-THEN-ELSE conditionals, FOR-NEXT and REPeat loops, procedures and functions with configurable parameters, array operations and slicing, local variables and automatic line numbering, along with the ability to extend the operating system through resident procedures. It also served as the command line interpreter for the QL's operating system, QDOS, making it one of the first second generation BASICs integrated directly into a microcomputer's operating system, letting users extend the system's own functionality through the language itself. Reviewers praised its structured improvements over earlier Sinclair BASIC while noting concerns about execution speed and limited numerical precision for business use.