The
Harvard architecture is a
computer architecture with physically separate
storage and signal pathways for instructions and data. The term originated from the
Harvard Mark I relay-based computer, which stored instructions on
punched tape (24 bits wide) and data in electro-mechanical counters. These early machines had data storage entirely contained within the
central processing unit, and provided no access to the instruction storage as data. Programs needed to be loaded by an operator; the processor could not
initialize itself.