>>>
>>>No. The DLL will not allow UI.
>>
>>I didn't think it would, and I wasn't even thinking about the UI part. I just didn't think it was going to allow you to "spawn off" a process to do the serial port monitoring and do anything else at the same time.
>
>Actually, if you have two processes doing different things, and neither required UI, you could probably do this.

Yes, but indirectly - you could call an out-of-process server, for example. if all I needed were lightweight comms in the background and I weren't running anything processor-intensive, MSCOMM32 could probably handle it in conjunction with VFPCOM to link VFP code to the OnComm event, but it's still a single thread of execution; VFP wouldn't interrupt a single atomic VFP command (for example, a horrible non-optimizable query) to execute an event handler; it only responds to events between lines of code...