Maxtor D540X-4K Product Manual page 25

For user capacities below 66,055,248 sectors (32 GB), inserting the AC jumper limits
the Number of Cylinders field to a value of 4,092, as reported in IDENTIFY
DEVICE data word 1. This allows software drivers to determine that the actual
capacity is larger than indicated by the maximum CHS, requiring LBA addressing to
use the full capacity.
For larger user capacities above 66,055,248 sectors (32 GB), inserting the AC jumper
limits the Total Number of User Addressable Sectors field to a value of 66,055,248,
as reported in IDENTIFY DEVICE data words 60 and 61. This protects hosts which
are not able to address beyond this capacity.
A summary of these effects for the Maxtor D540X-4K drives is shown in the
following table:
# % , 7 / 2 ' 4 1 7 6
C=16,383
H=16
    ) $
S=63
LBA=39,876,480
C=16,383
H=16
  ) $
S=63
LBA=78,198,750
C=16,383
H=16
  ) $
S=63
LBA=117,266,688
C=16,383
H=16
  ) $
S=63
LBA=156,301,488
( K I W T G  
C=4,092
H=16
S=63
LBA=39,876,480
C=16,383
H=16
S=63
LBA=66,055,248
C=16,383
H=16
S=63
LBA=66,055,248
C=16,383
H=16
S=63
LBA= 66,055,248
AT Connector and Jumper Location
Maxtor D540X-4K 20.4/40.0/60.0/80.0 GB AT
# % , 7 / 2 ' 4 + 0
Installation
3-7