Locomotive BASIC

Locomotive BASIC is a proprietary dialect of the BASIC programming language written by Locomotive Software. A modified form of it, known as Amstrad BASIC, was built into the ROM of the Amstrad CPC home computers, where it exposed the machine's firmware through dedicated commands for graphics, sound and disc access instead of leaving the programmer to fall back on assembly language. Development built on Mallard BASIC, which Locomotive had already written for an Acorn Z80 add-on for the BBC Micro, is reported to have taken about twelve weeks, and was described as very influenced by BBC BASIC. Two published versions of Amstrad BASIC exist: 1.0 on the CPC464, with a buggy DEC$ function, and 1.1 on the later models, which fixed it and added keywords such as FILL, FRAME and MASK. A later Locomotive BASIC-2 ran on IBM PC compatibles as a GEM application on the Amstrad PC1512 and PC1640.