DATA_REG_B
*data = inb(BASE + DATA_REG_B);
outb(BASE + DATA_REG_B, (length + 6) & 0xFF);
outb(BASE + DATA_REG_B, (length + 6) >> 8);
outb(BASE + DATA_REG_B, *(mtod(m, caddr_t) + m->m_len - 1));
outb(BASE + DATA_REG_B, 0);
outb(BASE + DATA_REG_B, (length + 6) & 0xFF);
outb(BASE + DATA_REG_B, (length + 6) >> 8);
outb(BASE + DATA_REG_B, *(mtod(m, caddr_t) + m->m_len - 1));
outb(BASE + DATA_REG_B, 0);