Int 1A Fn 91  - Pcmcia Socket Services V1.00 - Read One                    [X]

   AH = 91h
   AL = adapter number
   BL = socket number (01h to maximum supported by adapter)
   BH = attributes (see #0611)
   DX:SI = card address

Return: CF clear if successful
       AH destroyed
       CL/CX = value read
   CF set on error
       AH = error code (01h,07h,09h,0Bh,14h) (see #0580)
       CX may be destroyed

Note:  this function is only valid for I/O-mapped sockets

See Also: AH=92h,AH=93h,INT 21/AX=440Dh"DOS 3.2+"

Bitfields for PCMCIA attributes:
Bit(s) Description (Table 0611)
 2 even bytes only
 1 word rather than byte
 0 attribute memory instead of common memory