Writing a kernel driver for an USB-to-Serial adapter For my diploma thesis I have to write an USB-to-Serial Adapter driver. I must start from the source code of the serial port driver and the documentation given by the DDK from MS. I have some general questions: I am interested where could I found a more detailed documentation about the serial port, other that the DDK one, or/and could I found somewhere the source code of an USB-to-Serial Adapter driver ? It will be nice if you can give me the web address for this! It will help me a lot if somebody, who can say is a specialist or has a lot of experience in USB field, can give me some advices for writing this USB-to-Serial Adapter driver. Or perhaps he can give some literature which can help me to go further. And I have some special questions: What does the value which is written in the field Parameters.Others.Argument4 from the structure StackLocation of an IRP? More exactly what does the references saved there? Can I use in the source code of an USB-to-Serial Adapter driver a Read-Queue and a Write-Queue , which in the serial port driver is used on simultaneous reading and writing data from the port? The serial port use an Interrupt. So the Serial port driver has an ISR routine. All the external devices linked to an USB port does not use an Interrupt. How can I use the ISR routine of the serial port driver in the USB-to-Serial Adapter driver? Is this possible? What does the recursive calling of the routines SerialPutChar and SerialHandleModemUpdate ? Thanks in advance.

Oliver, a bit over my head my friend, but i can give you an excellent piece of advice............ make your apologies and post this in the XP FORUM instead, although not concurrent with your subject matter, it is FAR more frequently replied to and posted in than this particular section, and the people are generally very forgiving about subjects while offering the best advice on the net.