Hi all, ??????????? Thanks Tim, For that message. ????????????????????????? All this weekend i gone through the DDK documentation and got the knowledge of MSVAD. ????????????? Now i am using an shared memory to feed the recorder from the o/p of the player, I followed the following steps ????? 1. Create an section using ZwCreateSection. ????? 2. opened this section using ZwOpenSection ????? 3. Mapped the opened section to the current process virtual add?space using ZwMapViewOfSection ????? 4. Writting to the section using RtlCopy Memory ????? Untill step 4 all went good but while writing to the virtual address space i am getting crash "0X00000D1, {28d0000, 2, 1, a9b10dea}" ??????Can any ane explain me what is wrong, Can i use RtlCopyMemory in this senario or Not?? Thanks karthik?Sg -----Original Message----- From: Tim Roberts <timr@xxxxxxxxx> To: wdmaudiodev@xxxxxxxxxxxxx Sent: Mon, 15 Sep 2008 10:50 pm Subject: [wdmaudiodev] Re: about DMA buffer karthiksharmasg@xxxxxxx wrote: ??????????????????? I will look into that, you are saying there are 2 devices but when i use "device tree" it is showing only one device, what that this mean?. "Device" is an overloaded term.? The virtual microphone and the virtual speaker are handled by the same driver.? That's all I meant. -- Tim Roberts, timr@xxxxxxxxx Providenza & Boekelheide, Inc.