INT 15 - OS HOOK - DEVICE OPEN (AT,XT286,PS)
AH = 80h
BX = device ID
CX = process ID
CF clear
Return: CF clear if successful
AH = 00h
CF set on error
AH = status
80h invalid command (PC,PCjr)
86h function not supported (XT)
Note:   this function should be hooked by a multitasker which wishes to keep
track of device ownership; the default BIOS handler merely returns
successfully
SeeAlso: AH=82h

See also: 1581

1580 - OS HOOK - DEVICE OPEN (AT,XT286,PS)