INT 15 - OS HOOK - DEVICE BUSY (ATIBM PC AT,PSIBM PS/2, any model) AH = 90h AL = device type (see #00507) ES:BX -> request block for type codes 80h through BFh CF clear Return: CF set if wait time satisfied CF clear if driver must perform wait AH = 00h Notes: type codes are allocated as follows: 00-7F non-reentrant devices; OS must arbitrate access 80-BF reentrant devices; ES:BX points to a unique control block C0-FF wait-only calls, no complementary INT 15/AH=91h call floppy and hard disk 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. code uses this call to implement a timeout; for device types 00h and 01h, a return of CF set means that the timeout expired before the disk responded. this function should be hooked by a multitasker to allow other tasks to execute while the 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. is waiting for I/O completion; the default handler merely returns with AH=00h and CF clear SeeAlso: AH=91h,INT 13/AH=00h,INT 17/AH=00h,INT 1A/AH=83h (Table 00507) Values for device type: 00h disk 01h diskette 02h keyboard 03h PS/2IBM PS/2, any model pointing device 21h waiting for keyboard input (Phoenix 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.) 80h network FBh digital sound (Tandy) FCh disk reset (PSIBM PS/2, any model) FDh diskette motor start FEh printer