[OT] USB KVM switches

From: Eric Smith <eric_at_brouhaha.com>
Date: Wed Feb 2 16:29:03 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
Received on Wed Feb 02 2005 - 16:29:03 GMT