[OT] USB KVM switches
Eric Smith
eric at brouhaha.com
Wed Feb 2 16:29:03 CST 2005
Chris wrote:
> Although you state there are 9 different connectors, all of them are 100%
> compatible with each other, aren't they?
No. You can't connect two A receptacles together with an adapter, nor two
B receptacles, because USB is asymmetric. Hosts (and downstream hub ports)
have A receptacles, and devices (and upstream hub ports) have B receptacles.
Unless the device (or hub upstream port) has a captive cable, in which
case it has an A plug, which of course can be mated with a A receptacle.
Confused yet?
There are companies that sell wacky things like A-plug-to-A-plug and
B-plug-to-B-plug cables, which are explicitly disallowed in the USB spec.
I suspect that they didn't bother to read the spec and just expected that
customers would want to plug things together that way. Bizarre.
Eric
More information about the cctalk
mailing list