Hi Tim, Sorry, it's probably my loose use of KS. To quote (http://www.microsoft.com/whdc/device/audio/DirectKS.mspx) The plan for future Windows products is to provide built-in multimedia APIs and core services with very low latency and complete bit-for-bit transparency. These features should eliminate the need for any application program to circumvent the audio subsystem. The IOCTL requests used by the sample application rely on internal aspects of the current architecture that are likely to change in future operating systems. Be forewarned that the DirectKS approach is unlikely to work on operating systems after Windows XP and Windows Server 2003. ----- Original Message ----- From: Tim Roberts To: wdmaudiodev@xxxxxxxxxxxxx Sent: Friday, January 27, 2006 6:32 PM Subject: [wdmaudiodev] Re: Hi, Jerry Evans wrote: It is also wrth mentioning that the KS interface is likely to be dropped in Vista so the investment in time may be of limited value. Some of the Microsoft people here may be able to comment on this. Can you tell me what you mean by that? Stream.sys and AVStream are both sticking around for Vista. Are you saying that there might be a new, non-KS model for audio drivers (which I had not heard), or are you saying that DirectKS might not work? -- Tim Roberts, timr@xxxxxxxxx, DDK MVP Providenza & Boekelheide, Inc.