Int 13h, 06h Format Track and Set Bad Sector Flags fixed disk
Initializes each sector on a specified cylinder with sector
address and size information; also marks the sectors on the track
as unusable (bad) by setting the bad sector flag in the ID fields.
Only XTs may use this service.
Entry AH = 06h
AL = Interleave value
CH = Cylinder number (10-bit value; upper 2 bits in CL)
DH = Head number
DL = Drive number (Bit 7 must be set)
Return AH = Status of operation (See Service 01h)
CF Set if error, cleared otherwise
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Note
This service will destroy all previous contents of the disk.
The cylinder number is a ten-bit quantity (0 through 1023). Its
most significant two bits are in bits 7 and 6 of CL; the remaining
eight bits are in CH.
If an error is encountered, use Service 0h to reset the drive and
retry the operation.