A time-critical thread should be used for this call.

   ULONG ulDelay = 1;               // Number of milliseconds to wait
   ULONG ulSize2 = sizeof(ulDelay);

   DosOpen("TIMER0$ ", &hfile,
           &ulAction,0,0,ulOpenFlag,ulOpenMode,NULL);

   DosSetPriority(0,PRTYC_TIMECRITICAL,0,0);

   DosDevIOCtl( hfile,
                HRT_IOCTL_CATEGORY,
                HRT_BLOCKUNTIL,
                &ulDelay,
                ulSize2,
                &ulSize2,
                NULL,
                0,
                NULL);