INT 15 C - OS HOOK - DEVICE OPEN (ATIBM PC AT,XT286IBM PC XT/286,PSIBM PS/2, any model) 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(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware. The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. handler merely returns successfully SeeAlso: AH=81h,AH=82h (Table 00496) Values for status: 80h invalid command (PCIBM PC,PCjr) 86h function not supported (XTIBM PC XT)