Format of Interrupt Vector Table data storage (from 0000h:0000h)

Offset  Size    Description
 31Dh 16 BYTEs user-definable hard disk parameters for drive type 47
       (1989 AMI 386sx BIOS) (see INT 41,INT 46)
 32Dh 16 BYTEs user-definable hard disk parameters for drive type 48
       (1989 AMI 386sx BIOS) (see INT 41,INT 46)

Note:  these fields are used is the AMI BIOS setup is set to use the top of
     the interrupt table for the extended BIOS data area