[Windows 95 only.]
Returns the device parameters for the specified block device.
mov bx, Drive ;See below mov ch, DeviceCat ;See below mov cl, 60h ;Get device parameters mov dx, seg DriveDP ;See below mov ds, dx mov dx, offset DriveDP ;ds:dx points to a device parameters structure mov ax, 440Dh ;IOCTL for block device int 21h jc error_handler ;carry set means error
Drive
Specifies the drive for which parameters are requested (0 = default drive, 1 = A, 2 = B, and so on).
DeviceCat
Specifies the expected format of device parameters information structure.
|
Value |
Expected Device Parameters Structure |
|
08h |
DEVICEPARAMS (FAT16 or FAT12 drive. This call will work on FAT32 drives, but results are not reliable. Use the 48h form for FAT32 media). |
|
48h |
EA_DEVICEPARAMETERS (FAT32) (FAT32, FAT16 or FAT12) This value is supported on Windows 95 OEM Service Release 2 and later. |
Note: Because this call may be implemented in the device driver, the 48h form of this call may fail on FAT16 or FAT12 media. Therefore, applications making the 48h form of this call must fall back on the 08h form if the 48h call fails.
DriveDP
Points to the applicable device parameters structure containing the parameters for the specified block device. The format of the expected device parameters is indicated in the DeviceCat field above.
The special functions field in the device parameters structure determines whether the function retrieves current or default information. If the field is set to 1, the function retrieves information about the current medium in the drive. If the field is set to 0, the function retrieves information about the default medium for the drive.
If the function is successful, clears the carry flag. Otherwise, sets the carry flag and sets the AX register to one of the following error values.
|
Value |
Name |
|
0001h |
ERROR_INVALID_FUNCTION |
|
0002h |
ERROR_FILE_NOT_FOUND |
|
0005h |
ERROR_ACCESS_DENIED |
Get Device Parameters returns 0002h (ERROR_FILE_NOT_FOUND) if the specified drive number is invalid.