cc_get_imsk
cc_set_imsk(cc_get_imsk() | (1 << real_irq));
cc_set_imsk(cc_get_imsk() & ~(1 << real_irq));
cc_set_imsk(cc_get_imsk() & ~0x4000); /* Allow PIL 14 as well */
cc_set_imsk((cc_get_imsk() & ~0x8000) | 0x4000);