> > I run into this with FTDI chips. They in fact added the unique serial > number as a "feature". The PC I use for programming them has over a > hundred COM ports so far. I am not sure when Windows will run out ;-)> AFAIK you can program them with the same serial number, but in order > to program them, you have to plug them in, and Windows needs to > install the driver...I regularly run a utility provided by FTDI that goes in and strips out from the registry any instance of a PID / VID combination.  Since I use their VID by my own PIDs, I just tell it to kill off all the FTDI VID-ed devices.The MPROG utility has a check box for unique vs. same device serial number during programming.  My applications usually use the FT245 (plus eeprom) or FT245R and the non-VCP drivers under Windows.  So I have always programmed them with different serial numbers because I want to allow multiple devices on the same PC and they aren't going to look like COM ports anyway.  However, you might !
 want to check into exactly what in the programming API this check box does.  If it makes all the devices have the same serial number (including the newer "R" models) then your problem may go away.Rob
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