Hi swapnil kamble, ??? Thanks for that information Currently i am getting?an BSOD in?the IRP?method which seems to be difficult to solve but i will solve that,??? ????But according to the previous conversation in mailing list the MSVAD has 2 devices an simulated Speaker and an simulated mic, but when i used "Device tree" to explore it is showing only one device do you have any idea about it. If this works out to be 2 devices there is a way to solve this problem Tanks? kamble@xxxxxxxxx> To: karthiksharmasg@xxxxxxx Sent: Fri, 12 Sep 2008 12:35 pm Subject: [About DMA Buffer]VAC has implemented wave-pci Hi Karthik, ??????????????? I have also posted same question few days back. I also have same problem. I am not too sure about it but VAC implements Wave-PCI(really efficient no need of copying) instead of Wave-Cyclic. When I sent this thing on mailing list asked for suggestions few people got really fired up on me without understanding it properly. ??????????????? Are you facing the problem in WaveCyclic regarding delay. Audio is coming but getting breaked ? If yes then its most probably due to overrunning of read pointer ahead than write pointer. Since we cannot modify port class's mgmt about DMA buffer. But you can try out with WavePci. That's what I am doing right now. But I am BSOD in the most important function call of WavePci i.e. GetMapping(), once that big issue gets solved I think that delay will get removed. You also try it and let me know it. ??????????????? Otherwise last option I see is what you are doing right now. Sooner I am going to switch right now if BSOD still remains in GetMapping. By the way are getting atleast delayed noise through this IRP handling option ?? -- ...Swapnil || Hare Krishna Hare Krishna Krishna Krishna Hare Hare || || Hare Rama Hare Rama Rama Rama Hare Hare ||