•Digital is concept; it is an abstraction.
–There is no such thing as a “digital signal” versus an “analog signal”
–A digital signal is assumed to have one of N levels
–The simplest signal uses 2 levels. This is called a binary system and is what we will limit ourselves to in this presentation.
–All data is transmitted or stored as a analog representation
•Cables carry voltages or currents
•Hard drives store things using magnetic particles
•Computer Memory stores electric charge
–Error free digital requires that the analog signal is
not so degraded in the
process that it cannot be received uncorrupted.
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