HP Time-Shared BASIC

HP Time-Shared BASIC (HP TSB) is a BASIC programming language interpreter for Hewlett-Packard's HP 2000 line of minicomputer-based time-sharing computer systems. TSB is historically notable as the platform that released the first public versions of the game Star Trek.

The system implements a dialect of BASIC as well as a rudimentary user account and program library that allows multiple people to use the system at once. The systems were a major force in the early-to-mid 1970s and generated a large number of programs. HP maintained a database of contributed-programs and customers could order them on punched tape for a nominal fee.

Most BASICs of the 1970s trace their history to the original Dartmouth BASIC of the 1960s, but early versions of Dartmouth did not handle string variables or offer string manipulation features. Vendors added their own solutions; HP used a system similar to Fortran and other languages with array slicing, while DEC later introduced the MID/LEFT/RIGHT functions.

As microcomputers began to enter the market in the mid-1970s, many new BASICs appeared that based their parsers on DEC's or HP's syntax. Altair BASIC, the original version of what became Microsoft BASIC, was patterned on DEC's BASIC-PLUS. Others, including Apple's Integer BASIC, Atari BASIC and North Star BASIC were patterned on the HP style. This made conversions between these platforms somewhat difficult if string handling was encountered.