Category: DOS kernel
INT 21 - European MS-DOS 4.0 - SLEEP AH = 89h CX = time in milliseconds or 0000h to give up time slice Return: CF clear if successful CX = 0000h CF set on error AX = error code (interrupted system call) CX = sleep time remaining Desc: suspend the calling process for the specified duration Notes: the sleep interval is rounded up to the next higher increment of the scheduler clock, and may be extended further if other processes are running this call may be interrupted by signals (see AH=8Dh) reportedly called by Microsoft C 4.0 startup code background processes have higher priority than the foreground process, and should thus periodically yield the CPU SeeAlso: AH=81h,INT 15/AX=1000h,INT 2F/AX=1680h,INT 7A/BX=000Ah