LECTURE 5: CPU and MEMORY

electronic components I. Four main types of electronic components in computers: 1. transistors/resistors 1. transistors/resistors semi – conductors that acts as an electronic switch that can either conduct electricity or prevent its flow 2. integrated circuit 2. integrated circuit (a.k.a. “IC”) – a chip that contains transistors/resistors 3. circuit board 3. circuit board – the actual conductive pathways that connect components inside the CPU motherboard all of these are mounted on a larger circuit board called the motherboard

II. The CPU: Central Processing Unit The CPU is the “brain” of the computer. It: receives input interprets instructions from programs processes data controls output directs other components of the system to act

III. Parts of a CPU control unit control unit – coordinates the flow of data and instructions ALU ALU – (arithmetic logic unit) performs calculations and comparisons of data registry registry – holds program instructions, data, values, and memory locations as the processor executes a program busses busses – carries information from the CPU to a device

IV. Control Unit clock the control unit contains a clock that generates a uniform stream of electrical pulses that synchronize the operation of the CPU and other components the faster this clock rate, the faster the CPU can process information this clock speed is measured in gigahertz (GHZ)

V. RAM: Random access Memory main Before programs are executed or before data is processed they must enter into main memory (a.k.a. primary storage or RAM) Ram does the following: accepts and holds programs instructions and data acts as the CPU’s source of data and instructions as a destination for operation results holds the final processed information until it can be sent to the desired output or secondary storage device RAM is way faster to access than secondary storage Data is located in the main memory using addresses RAM is volatile (changeable) and requires constant change, so save your work often to secondary storage ROM (read only memory) is different in that it is a permanent instructions

Two Major Processors: Intel Pentium Pentium 2 Pentium 3 Pentium 4 Core Duo and Quad DuoAMD Turon Athlon Opteran