At 08:54 PM 5/4/2006, Jim Lux wrote: >At 07:59 PM 5/4/2006, Robert McGwier wrote: > >Microsoft has chosen to say that you have a brand new device if you move > >from one USB socket to the one right next to it. The only way to > >prevent this is to install it on all ports (by physically moving it) or > >to mark things in a way that you are always hooking things up in the > >same connect point. > >Not always true. > >I've got a stack of 5 USB to serial converters here that I've been playing >with, trying to make sense of this very thing. > >It depends on how the driver is written. Every USB device has a serial >number, and some drivers relate the "windows device" to the serial number >(for instance, a USB com device might always show up as COM5, regardless of >which hub it's plugged into). > >Other devices will be "position specific".. usually that's because the >driver is taking the "low road" of just assigning indices in the order found.
I have learned some more about USB.. While there is a serial number in the device spec, not all manufacturers implement it, and, some burn the same SN into all devices. Such devices can't be followed around, regardless of which port they are plugged into. And, there's actually a registry setting that tells Windows to *ignore* the SN, should it appear, apparently used for hardware for which you're only ever going to hook one of them up (a keyboard?) The SN is also used to trigger the "driver installation" dialog. _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
