Function 440Dh Minor Code 42h Format Track on Logical Drive

mov bx, Drive ;0 = default, 1 = A, 2 = B, etc.

mov ch, 08h ;device category (must be 08h)

mov cl, 42h ;Format Track on Logical Drive

mov dx, seg FormatBlock

mov ds, dx

mov dx, offset FormatBlock ;ds:dx points to FVBLOCK structure

mov ax, 440Dh ;IOCTL for Block Device

int 21h

jc error_handler ;carry set means error

Format Track on Logical Drive (Function 440Dh Minor Code 42h) formats and verifies a track on the specified device.

Parameters

Drive

Specifies the drive on which the track is to be formatted and verified (0 = default drive, 1 = A, 2 = B, etc.).

FormatBlock

Points to an FVBLOCK structure that specifies the head and cylinder to format. The FVBLOCK structure has the following form:

FVBLOCK STRUC

fvSpecFunc db 0 ;special functions (must be zero)

fvHead dw ? ;head to format/verify

fvCylinder dw ? ;cylinder to format/verify

FVBLOCK ENDS

For a full description of the FVBLOCK structure, see Chapter 3, “File System.”

Return Value

If the function is successful, the carry flag is clear. Otherwise, the carry flag is set and the AX register contains an error value, which may be one of the following:

Value

Name

0001h	ERROR_INVALID_FUNCTION
0002h	ERROR_FILE_NOT_FOUND
0005h	ERROR_ACCESS_DENIED

Comment

Format Track on Logical Drive returns 0002h (ERROR_FILE_NOT_FOUND) if the specified drive number is invalid.