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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 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 is waiting for I/O completion; the default handler merely returns with AH=00h and CF clear
See Also:
AH=91h - INT 13/AH=00h - INT 17/AH=00h - INT 1A
(Table 00507)
Values for device type:
00h disk
01h diskette
02h keyboard
03h PS/2 pointing device
21h waiting for keyboard input (Phoenix BIOS)
80h network
FBh digital sound (Tandy)
FCh disk reset (PS)
FDh diskette motor start
FEh printer
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