Epson 486SX - Manual (Page 148)

For an Epson hard disk drive, it is best to accept the
recommended skewed sector (also called the interleave
factor) of 1 since this setting allows your drive to perform
more efficiently. For other hard disk drives, you may need
to change this value if the documentation that came with
the disk recommends a different number.
To accept the default, select Y. Then go to step 3.
To enter a new value, select N. You see the following prompt:
Enter new skewed sectors in
format (1-16):
Enter the recommended number (from 1 through 16) which
equals the maximum sector number for the drive minus 1.
Then press [Enter.
3. Next you see this prompt:
Accept recommended skewed sectors per
head in format : 0 ? (Y/N)
For an Epson hard disk drive, accept the recommended value
of 0. For another type of drive, use the value recommended
in the documentation for the drive.
To accept the default, select
Y .
To enter a new value, select N. You see the following prompt:
Enter new skewed sectors per head
in format (0-16):
Enter the recommended number (from 0 through 16) which
equals the maximum sector number for the drive minus 1.
Then press
A - 6 Physically Formatting a Hard Disk