HelenOS sources

CLK_CONST          99 kernel/arch/amd64/src/drivers/i8254.c 	pio_write_8(CLK_PORT1, (CLK_CONST / HZ) & 0xf);
CLK_CONST         100 kernel/arch/amd64/src/drivers/i8254.c 	pio_write_8(CLK_PORT1, (CLK_CONST / HZ) >> 8);
CLK_CONST          99 kernel/arch/ia32/src/drivers/i8254.c 	pio_write_8(CLK_PORT1, (CLK_CONST / HZ) & 0xf);
CLK_CONST         100 kernel/arch/ia32/src/drivers/i8254.c 	pio_write_8(CLK_PORT1, (CLK_CONST / HZ) >> 8);
HelenOS homepage, sources at GitHub