Re: Missed It By That Much

wdstarr@[EMAIL PROTECTED]
 (William December Starr) writes:

> In article <200804231443.m3NEhPZ6173654@[EMAIL PROTECTED]
>,
> mstemper@[EMAIL PROTECTED]
 said:
> 
> > I read something over the winter that had a character unlocking a
> > door with a "Chromokey".  It wasn't explained, but I took it to be
> > a device that sent a particular pattern of colored light to the
> > lock.
> >
> > This is very close to the RFID chip embedded in the badge that I
> > use to unlock the door to my place of employment every morning.
> > Really, the only difference is wavelength.
> 
> Is the hypothetical Chromokey's "pattern of colored light" all in
> the same color or multi-colored?  If the latter then we have the
> distinction that RFID only uses a single wavelength (frequency).

Plus the RFID is a passive device with no power source. The "door"
provides the power and the initial message. The RFID then "reflects" the
message back modified.