IC Tune, Chiptune / Integrated Circuit Music, Chip Music

IC music, Chiptune, generally refers to melodic pieces of music that are automatically synthesised through integrated circuit technology. Usually the sound source of this type of music is the underlying waveform or wavetable synthesis. Chip music is divided into two main categories as follows.

The first category is often referred to as “music chips” i.e. signals generated by Melody ICs. These are special purpose integrated circuits (ASICs) whose sole function is to synthesise melodies in real time based on the music data built in. The manufacturer pre-programs, burns or masks the melody to be played in the internal read-only memory (ROM) of the melody chip. Once powered up, the logic circuitry inside the music chip sequentially retrieves the note data from the ROM and sends it to an oscillator to generate waveforms of different frequencies to produce a sound output.

Due to the limitations of integration, the number of channels built into these chips (the number of channels can be considered as polyphony as a single channel can usually only synthesise a single frequency at the same time) is usually small, and the expressiveness of the output melody is therefore limited. The KD9300 (HS-088) series of monophonic music chips are commonly used in China, but they only have a single channel square wave without any envelope, and the output signal is monotonous and harsh. The SVM7910 series, developed and produced by SEIKO EPSON in the 1970s, is generally regarded as the world's first stand-alone music synthesizer chip. Matsushita, Sharp and other companies followed with a variety of in-house models. These Japanese-made music ICs usually had two to four square wave channels (a few had noise channels, which could be used to simulate percussion instruments) and had an envelope effect, making them more natural and pleasant to listen to than their predecessors. Seiko Epson also later introduced the SVM7570 series of wavetable-based music ICs, which are almost as good as FM synthesis.

The second category is music output from personal computers (Commodore 64, Amiga, etc.) and game consoles (Family Computer, NES, Atari series consoles, etc.), which were popular in Europe, America and Japan in the 1970s and 1980s. These are mainly hardware sound generators (e.g. PSG or SSG) that are synthesised in real time by software running on the CPU. Electronic keyboards from the 70s and 80s can also be considered in this category.

Today, as technology and aesthetics have evolved, the synthesis of such music chips has been replaced by digital recording and other technologies, and has gradually faded from view. Those still in production are limited to monophonic square wave or low sampling rate PCM playback for less demanding cue sounds (e.g. sprinkler/garbage truck, alarm), toy sound effects, etc.

This page will focus primarily on the introduction and audio recording of the first category (i.e. stand-alone music chips).

IC music/CHIPTUNE included on this site.