Namco 163

Namco 163

Overview

The Namco 163 is a sound and memory-management chip used in Nintendo Famicom cartridges. Also known as the N163 or Namco 106, it adds programmable wavetable synthesis to the Famicom's built-in audio hardware.

The chip can provide up to eight additional wavetable channels. Its distinctive architecture and limited internal waveform memory give the Namco 163 a characteristic sound that is very different from the Famicom's standard pulse and triangle channels.

Technical characteristics

• Manufacturer: Namco
• Type: Wavetable synthesis / cartridge mapper
• Channels: Up to 8
• Waveform resolution: 4-bit samples
• Internal RAM: 128 bytes
• Waveform memory: Shared with channel registers
• System: Nintendo Famicom / NES cartridges

Wavetable synthesis

Unlike the Famicom's fixed pulse and triangle generators, the Namco 163 allows the programmer to define custom waveforms in internal RAM.

The waveforms are stored as 4-bit samples and can have different lengths. This makes it possible to create basses, leads, bells, percussion and unusual digital timbres.

Eight channels

The Namco 163 can provide up to eight wavetable channels. However, all eight channels share the chip's limited processing resources and waveform RAM.

When more channels are enabled, each channel receives less processing time. This creates one of the Namco 163's most recognizable characteristics: increasing the number of active channels can introduce additional digital artifacts and reduce the effective audio quality.

Shared waveform memory

The chip contains 128 bytes of internal RAM shared between channel registers and waveform data. Each active channel requires part of this memory for its control registers, leaving less space available for waveforms as more channels are enabled.

This creates an unusual relationship between polyphony and waveform complexity. Using fewer channels allows longer or more detailed waveforms to be stored.

Tracker relevance

The Namco 163 is particularly important to tracker music because its architecture is almost perfectly suited to wavetable tracker techniques. A tracker can define custom waveforms and sequence them at different pitches across several independent channels.

Modern trackers can reproduce the chip's waveform memory limitations, channel allocation and time-division behaviour, making it possible to create music that closely reflects the original hardware.

Historical importance

The Namco 163 is one of the most distinctive expansion sound systems for the Famicom. It demonstrates how cartridge hardware could substantially expand the capabilities of a console's built-in sound system without modifying the console itself.

Its combination of wavetable synthesis, extremely limited RAM and unusual time-division multiplexing also gives it a highly recognizable sound that remains popular among modern chiptune composers.

Related soundchips

• NES APU
• Konami VRC6
• Konami VRC7
• Sunsoft 5B
• Hudson HuC6280
• Game Boy APU

Further reading

• NESdev – Namco 106 Audio
• FamiStudio – Expansion Audio
• Furnace – Namco 163