Hudson Soft HuC6280

The HuC6280 8-bit microprocessor is Japanese company Hudson Soft's improved version of the WDC 65C02 CPU, an upgraded CMOS version of the popular NMOS-based MOS Technology 6502 8-bit CPU, manufactured for Hudson by Seiko Epson and NEC.

The HuC6280 contains a 65C02 core which has several additional instructions and a few internal peripheral functions such as an interrupt controller, a memory management unit, a timer, an 8-bit parallel I/O port, and a programmable sound generator (PSG).

This can be set up with an 8-bit register (MPR0-7) that contains the most significant eight bits of the address of the 8 KB segment in physical memory.

PSG-styled wavetable synthesis provides six sound channels, which can be conveniently paired according to the functionality they provide: Waveform playback is the most common and allows a 32-byte, 5-bit unsigned linear sample to be played back at selected frequencies.

White noise is used to simulate percussion instruments and effects, such as explosions, by means of a pseudo-random square wave.