Category: BIOS
Flags: callout or callback (usually hooked rather than called)
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 (see #00496) 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=81h,AH=82h