Techniques & Technology

Sinclair BASIC

The Spectrum's built-in language

Sinclair BASIC came built into the ZX Spectrum ROM, providing accessible programming that launched countless coding careers.

SpectrumZX81 programmingbasicsinclair 1980–present

Overview

Sinclair BASIC was the first programming experience for millions of Spectrum owners. Built into ROM, it was available immediately upon power-on. The language handled graphics, sound, and input through simple commands. While slow for games, it served as gateway to programming for a generation who would progress to machine code.

Fast facts

  • Platform: ZX Spectrum (and ZX81 predecessor).
  • Location: 16KB ROM.
  • Features: graphics, sound, I/O commands.
  • Editor: single-key entry mode.
  • Speed: interpreted, relatively slow.

Distinctive features

What made Sinclair BASIC notable:

  • Single-key entry: keywords entered with single keypress.
  • Error messages: helpful (for the era) feedback.
  • Graphics commands: PLOT, DRAW, CIRCLE.
  • Sound: BEEP command for simple tones.

Learning progression

Typical Spectrum programmer path:

  • BASIC: first programs, understand concepts.
  • Hit limits: games too slow in BASIC.
  • Machine code: move to assembly for speed.
  • Hybrid: BASIC wrapper calling machine code.

See also