UNIT 3: Computers
3.1: Hardware
❖ Computer: A machine that takes some kind of input from its surroundings, then processes it to produce an
output.
❖ A computer contains hardware [physical components] as well as software.
❖ Software: A set of programs running on hardware to help the computer complete operations.
, [3.1.1] The von Neumann Stored Program Concept
❖ The idea of a universal computer capable of doing many different tasks emerged from Alan Turing and John
von Neumann in the 1930s and 1940s. Previously, computing machines were built to perform just one job.
❖ The von Neumann architecture consists of main memory and a central processing unit [CPU], interconnected by
buses
❖ Von Neumann also envisaged some kind of secondary storage to provide long-term storage for programs and
data when they were not immediately required by the computer.
❖ Main memory refers to RAM [Random Access Memory].
❖ RAM is typically measured in gibibytes [GiB].
❖ Data and instructions are represented as binary numbers in groups of bytes [8 bits].
❖ Writing => When the CPU saves data into memory.
❖ Reading => The reverse process - when the CPU must specify which part of memory to read
from.
3.1: Hardware
❖ Computer: A machine that takes some kind of input from its surroundings, then processes it to produce an
output.
❖ A computer contains hardware [physical components] as well as software.
❖ Software: A set of programs running on hardware to help the computer complete operations.
, [3.1.1] The von Neumann Stored Program Concept
❖ The idea of a universal computer capable of doing many different tasks emerged from Alan Turing and John
von Neumann in the 1930s and 1940s. Previously, computing machines were built to perform just one job.
❖ The von Neumann architecture consists of main memory and a central processing unit [CPU], interconnected by
buses
❖ Von Neumann also envisaged some kind of secondary storage to provide long-term storage for programs and
data when they were not immediately required by the computer.
❖ Main memory refers to RAM [Random Access Memory].
❖ RAM is typically measured in gibibytes [GiB].
❖ Data and instructions are represented as binary numbers in groups of bytes [8 bits].
❖ Writing => When the CPU saves data into memory.
❖ Reading => The reverse process - when the CPU must specify which part of memory to read
from.
