Int 1A Fn 81  - Pcmcia Socket Services V1.00 - Register Status Change Cal  [X]

   AH = 81h
   DS:DX -> callback routine (see #0581) or 0000h:0000h to disable

Return: CF clear if successful
       AH destroyed
   CF set on error
       AH = error code (see #0580)

Note:  the callback will be invoked on any socket changes whose notification
     has not been disabled with the status change enable mask; it may be
     invoked either while processing a hardware interrupt from the adapter
     or while processing the following Socket Services request

See Also: AH=80h"PCMCIA",AH=82h"PCMCIA"

(Table 0581)
Values PCMCIA callback routine is invoked with:
   AL = adapter number
   BH = status change interrupt enable mask (see #0582)
   BL = socket number
   DH = current socket status (see #0583)
   DL = current card status (see #0584)

Return: all registers preserved

Notes: the callback may be invoked during a hardware interrupt, and may not
     call on Socket Services
   the callback will be invoked once for each socket with a status change

Bitfields for PCMCIA status change interrupt enable mask:
Bit(s) Description (Table 0582)
 7 card detect change
 6 ready change
 5 battery warning change
 4 battery dead change
 3 insertion request
 2 ejection request
 1-0   reserved (0)

Bitfields for PCMCIA current socket status:
Bit(s) Description (Table 0583)
 7 card changed
 6 reserved (0)
 5 card insertion complete
 4 card ejection complete
 3 card insertion request pending
 2 card ejection request pending
 1 card locked
 0 reserved (0)

Bitfields for PCMCIA current card status:
Bit(s) Description (Table 0584)
 7 card detect
 6 ready
 5 battery voltage detect 2 (battery warning)
 4 battery voltage detect 1 (battery dead)
 3-1   reserved (0)
 0 write protected