SDS BASIC

SDS BASIC, also known as CP-V BASIC, Batch BASIC or Sigma BASIC depending on the version, is a BASIC programming language compiler for Scientific Data Systems's (SDS) Sigma series mainframe computers, originally released in 1967. Xerox purchased SDS in 1969 and began rebranding it as Xerox Data Systems, and finally just Xerox, at which time the language became known as Xerox BASIC.

The original versions did not include support for string variables, although this was added for the version running under the CP-V operating system when it was released in 1971. The string library allowed manipulation of strings using array slicing syntax, similar to the system found in HP Time-Shared BASIC and a number of microcomputer BASICs like Integer BASIC and Atari BASIC.

This style of string manipulation differs from the model introduced in DEC's BASIC-PLUS, which used string functions. Altair BASIC was patterned on BASIC-PLUS, and this style became the de facto standard after the cross-platform version, Microsoft BASIC, became almost universal during the home computer era. This makes conversion from SDS to modern dialects somewhat difficult.

SDS BASIC is historically notable as the platform on which the original Star Trek computer game was written in the summer of 1971.^[1]