Int 13 Fn 1D  - IBMcache.sys - Cache Status                                [c]

   AH = 1Dh
   AL = subfunction
       01h get status record
       DL = drive???

       Return: ES:BX -> status record (see below)
           CF set on error
               AH = error code
       02h set cache status
       ES:BX -> status record (see below)
       DL = drive???

       Return: CF set on error

Format of status record:
Offset Size    Description
 00h   DWORD   total number of read requests
 04h   DWORD   total number of hits
 08h   DWORD   number of physical disk reads
 0Ch   DWORD   total number of sectors requested by physical disk reads
 10h  6 bytes  ???
 16h   DWORD   pointer to start of error list
 1Ah   DWORD   pointer to end of error list
 1Eh   WORD    ???
 20h   BYTE    using extended memory if nonzero
 21h   BYTE    ???
 22h  4 BYTEs  ASCII version number
 26h   WORD    cache size in KB
 28h   WORD    sectors per page

Format of error list:
Offset Size    Description
 00h   DWORD   relative block address of bad page
 04h   BYTE    drive
 05h   BYTE    sector bit-map
 06h   WORD    next error