Re: Turn on Apple to preserve it?

[Eric Smith <eric@brouhaha.com>]

"Michael J. Mahon" <mjmahon@aol.com> writes:
> The USB data lines are differential, and moderately resistant to
> common-mode voltages.

No, not really.  The differential common mode range spec, Vcm, is
0.8 to 2.5 volts for low speed and full speed.  For high speed,
Vhscm is -50mV to +500mV.  See Table 7-7 of the USB spec (rev 2.0).

Maybe you could get away with more than that in some cases, but you
can't count on it.

Eric