Function 4411h Query IOCTL Device

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

mov ch, 8 ;IOCTL category to check. Must be 8

mov cl, Function ;IOCTL function to check

mov ax, 4411h ;Query IOCTL Device 4411h

int 21h

jnc supported ;carry clear means IOCTL supported

Query IOCTL Device (Function 4411h) determines whether the specified IOCTL function is supported for the given drive.

Parameters

Drive

Specifies the drive (0 = default, 1 = A, 2 = B, etc.).

Function

Specifies a Function 4401 minor code. It can be one of the following:

Value

Meaning

40h	Set Device Parameters
41h	Write Track on Logical Drive
42h	Format Track on Logical Drive
46h	Set Media ID
60h	Get Device Parameters
61h	Read Track on Logical Drive
62h	Verify Track on Logical Drive
66h	Get Media ID
68h	Sense Media Type

Return Value

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

Value

Name

0001h	ERROR_INVALID_FUNCTION
0005h	ERROR_ACCESS_DENIED
000Fh	ERROR_INVALID_DRIVE

Comments

Query IOCTL Device returns 0001h (ERROR_INVALID_FUNCTION) if the device driver has no support for IOCTL functions. The function returns 0005h (ERROR_ACCESS_DENIED) if the device driver supports IOCTL functions but does not support the specified IOCTL.