SLAVE_ICW4_DEFAULT
writeb(SLAVE_ICW4_DEFAULT, rm200_pic_slave + PIC_IMR);
outb_pic(SLAVE_ICW4_DEFAULT, PIC_SLAVE_IMR);
outb_p(SLAVE_ICW4_DEFAULT, PIC_SLAVE_IMR); /* (slave's support for AEOI in flat mode is to be investigated) */