Fixed Disk Params (XT,AT,XT2,XT286,PS except ESDI disks)

        Offset Size    Contens
        00h    Word    Cylinders
        02h    Byte    Heads
        03h    Word    Starting reduced write current cylinder (XT only,
                       0 for others)
        05h    Word    Starting write pre-comp cylinder
        07h    Byte    Maximum ECC burst length
        08h    Byte    Control byte
                         1xxx xxxx  Disable access retries
                         x1xx xxxx  Disable ECC retries
                         xx1x xxxx  Set if manufacturer's defect map on
                                    max cylinder+1
                         xxx1 xxxx  Always 0
                         xxxx 1xxx  Set if more than 8 heads
                         xxxx x111  Drive option (XT only, 0 for others)
        09h    Byte    Standard timeout (XT only, 0 for others)
        0Ah    Byte    Formatting timeout (XT only, 0 for others)
        0Bh    Byte    Timeout for checking drive (XT only, 0 for others)
        0Ch    Word    Landing zone (AT/PS2)
        0Eh    Byte    Sectors/track (AT/PS2)
        0Fh    Byte    0