Replying to a message of Martin Rosenfeld to All:

 MR> Please tell me what a MAC is. Is it a brand of Ethernet chip 
 MR> or is it something related only to remote booting or both.

A personal computer made by Apple. 

You're probably thinking of a MAC address, that's a unique hardware address
that's built into every network card.  TCP/IP software puts that address someplace
in the header of every packet it sends out, along with the originating and
destination
IP addresses and a bunch of other stuff.

--- FleetStreet 1.19+