RF5C68

Ricoh RF5C68

Overview

The Ricoh RF5C68 is an eight-channel PCM sound chip used in several Japanese computer and arcade systems. It is particularly associated with the Fujitsu FM Towns computer and Sega arcade hardware.

The chip is designed around digital sample playback rather than FM or PSG synthesis. Its eight PCM channels can play independent samples simultaneously, making it well suited to voices, sound effects and sampled musical instruments.

Technical characteristics

• Manufacturer: Ricoh
• Type: PCM sample playback
• Channels: 8
• Sample playback: PCM
• Typical sample rate: Around 19.6 kHz
• Memory: External waveform memory
• Systems: FM Towns, Sega System 18, Sega System 32

PCM architecture

Each of the eight channels can access digital waveform data and play it back at a programmable rate. The architecture is particularly well suited to short samples such as drums, percussion, instrument attacks, voices and sound effects.

Unlike an FM synthesizer, the RF5C68 does not generate complex tones from operators. Its character comes primarily from the samples stored in its waveform memory.

FM Towns

The RF5C68 is closely associated with Fujitsu's FM Towns family of computers. In these systems it complemented FM synthesis hardware, allowing the computer to combine synthesized sounds with digital samples.

This combination was particularly useful for multimedia software and games that required both music synthesis and recorded sound.

Sega arcade hardware

The RF5C68 was also used in Sega arcade systems including System 18 and System 32. In these machines, PCM playback could complement FM synthesis hardware such as the Yamaha YM2151.

Tracker relevance

The RF5C68 is an important example of the sample-based side of tracker and game music technology. Eight independent PCM channels provide enough voices for melodies, basses, percussion and effects to coexist in a conventional tracker-style arrangement.

Modern tracker software can reproduce the RF5C68's characteristic limitations by restricting sample playback to its available channels and reproducing its sample memory architecture.

Historical importance

The RF5C68 occupies an interesting position between dedicated FM synthesizers and the much more powerful PCM systems that became common during the 1990s. It offered straightforward multichannel digital sample playback while remaining relatively simple to integrate into arcade and computer hardware.

Related soundchips

• Ricoh RF5C164
• SegaPCM
• OKI MSM6295
• Yamaha YM2151
• Yamaha YM2612

Further reading

• RF5C68 – Video Game Music Preservation Foundation