To set Channel A to middle C (~261 Hz) with a 1 MHz clock:
First, a point of clarity: the KC89C72 is not a household name like the Intel 8086 or the Zilog Z80. It is, in fact, a near-perfect clone of the General Instrument AY-3-8910, a Programmable Sound Generator (PSG) chip. If that name sounds familiar, it is because the AY-3-8910—and its twin, the Yamaha YM2149—provided the beeps, bloops, and bass lines for arcade classics like Gyruss , home computers like the Amstrad CPC, and the legendary Sinclair ZX Spectrum 128. kc89c72 datasheet
The KC89C72 is a member of the MCS-51 family of microcontrollers, designed by Intel and later manufactured by several other companies, including OKI Semiconductor, which produced the KC89C72. This microcontroller is built around an 8051 core, with a clock speed of up to 12 MHz. It features 4 KB of on-chip ROM, 128 bytes of RAM, and a range of peripherals, including timers, counters, and serial interfaces. To set Channel A to middle C (~261
