0100-0107 ---- PS/2 POS (Programmable Option Select)


0100   r   POS register 0  Low adapter ID byte
0101   r   POS register 1  High adapter ID byte

0102   r/w POS register 2  option select data byte 1
        bit 0 is card enable (CDEN)

0103   r/w POS register 3  option select data byte 2
0104   r/w POS register 4  option select data byte 3
0105   r/w POS register 5  option select data byte 4
        bit 7  channel active (-CHCK)
        bit 6  channel status

0106   r/w POS register 6  Low subaddress extension
0107   r/w POS register 7  High subaddress extension