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[📷 suggested: photo of a datasette / ZX tape deck]

Overview

Before disks were common, games rode in on humble audio cassettes. The computer listened for pulses, decoded them into bits, and slowly filled RAM with the program you were desperate to play.

Fast facts

  • Data rate: roughly 50–70 bytes per second using the C64’s default loader (~5 minutes for a 16 KB game).
  • Storage: up to 100–120 KB per side with careful duplication.
  • Commands: LOAD for programs, LOAD "*",8,1 appeared later for disks.

The journey from tape to screen

  1. Motor on: LOAD (or PRESS PLAY ON TAPE) starts the datasette motor and the computer listens for pilot tones.
  2. Header: a short block announces the filename, type, and length, giving BASIC the info it needs.
  3. Data blocks: the program streams in, each chunk followed by a checksum byte. Errors meant rewinding a few turns and trying again.
  4. Turbo loaders: custom routines replaced the slow KERNAL code for speed—and colourful border theatrics while you waited.
  5. Autoboot: some commercial tapes auto-ran after loading by appending SYS commands or self-starting loaders.

[🎥 suggested: short clip of a turbo loader with flashing border effects and progress counter]

Why tapes ruled (especially in Europe)

  • Cheap & everywhere: blank cassettes cost pennies and every music shop stocked them.
  • Copyable: home duplication spread shareware, piracy, and schoolyard trading.
  • Publisher-friendly: mail-order and newsagents could stock them without committing to expensive disks or cartridges.

Rituals and remedies

  • Head alignment: tiny screwdrivers adjusted azimuth; some kids taped charts to their decks.
  • Volume games: spectrum owners nudged the volume knob; C64 users toggled tone controls on hi-fis.
  • Environmental noise: creaky tape mechanisms or loud siblings could ruin a load, so many households treated loading like a sacred quiet time.

Lesson connections

  • Week 1 and 2 BASIC programs fit comfortably into a single tape block—perfect for sharing just like in the 1980s.
  • Later courses discuss turbo loaders when we explore custom I/O and KERNAL routines.
  • The Transition module’s deep dive into memory explains how those checksums protect the bytes you just loaded.

See also