DOS Fn 4410H: IOCTL Query IOCTL Support for Handle
Compatibility: 5.0+
Expects: AX 4410H
BX file handle (device or disk file)
CH device category: 00H=unknown
01H=COMn (DOS 3.3+)
03H=console (screen + keyboard) (DOS 3.3+)
05H=parallel printer (DOS 3.2+)
CL subfn number to query:
45H = set retry iteration count --see fn 440CH 45H
65H = query retry iteration count--see fn 440CH 65H
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Returns: AX error code if CF is set to CY
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Info: This checks to see if certain IOCTL functions are supported for a
particular file handle.
On return, if CF=NC=0, then the specified function IS supported.
On return, if CF=CY=1, then the error code in AX indicates why
the function is not supported:
AX=0001 (invalid function): no support for IOCTL fns at all.
AX=0005 (access denied): that fn (in CL) is not supported.
See Also: Fn 44H (IOCTL)
Fn 440cH (generic IOCTL for character devices)
DOS Functions
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