T6W28
Toshiba T6W28
Overview
The Toshiba T6W28 is a programmable sound generator derived from the architecture of the Texas Instruments SN76496 family.
It is particularly associated with Sega hardware and is closely related to the PSG used in the Sega Master System and other Sega systems.
The T6W28 retains the characteristic three-tone-channel plus noise-channel architecture of the SN76496 family.
Technical characteristics
- Manufacturer: Toshiba
- Model: T6W28
- Family: SN76489-compatible PSG
- Channels: 3 tone + 1 noise
- Synthesis: PSG
- Tone waveform: Square wave
- Noise: Yes
- Typical use: Sega hardware
SN76489 compatibility
The T6W28 follows the programming model of the SN76489 family. Three tone channels provide the melodic and harmonic voices, while a dedicated noise channel is available for percussion and sound effects.
This makes music written for the architecture relatively compact and efficient, although the available synthesis features are considerably simpler than those of later FM and sample-based chips.
Sega systems
The T6W28 is strongly associated with Sega's 8-bit hardware. Its sound character is therefore an important part of the audio identity of Sega's early home consoles and related systems.
The architecture demonstrates how a relatively simple PSG could be used to produce complete game soundtracks with only four logical sound channels.
Tracker relevance
The T6W28 is relevant to tracker and chiptune history because its limited channel count encouraged composers to use software techniques to create additional perceived voices.
Fast arpeggios, alternating notes and rapid volume changes could be used to make the three tone channels sound much more sophisticated than the hardware architecture initially suggests.
Historical importance
The T6W28 is an important example of the widespread SN764xx-derived PSG architecture used in video-game hardware.
Its association with Sega makes it particularly relevant when documenting the evolution of Japanese console and arcade music hardware.
Related soundchips
- Texas Instruments SN76496 — The architecture on which the T6W28 is based.
- Texas Instruments SN76489 — Closely related PSG.
- Yamaha YM2149 — Alternative three-channel PSG architecture.
Further reading
In a nutshell
- Name: T6W28
- Manufacturer: Texas Instruments
- Family: SN76489
- Type: PSG
- Year: 1980
- Channels: 4
- Synthesis: Tone / Noise
- Sample support: 0
- Description: Japanese variant of the SN76489 family used in Sega hardware.
- Aliases: T6W28
- Computer:
- Console: Sega Master System
- Arcade:
- Official Name: T6W28