Computer Hardware (CSA Midterm 1)

Computer hardware

Collection of physical parts of a computer system. It can be categorized as having either external or internal components.

1st Generation (Vacuum Tubes)

• Invented in parallel to the electric bulb and used a similar concept.

• The switching capability, which is translated into turning on and off a particular bit, was the main reason for the important role the vacuum tubes played in early computers.

• It can also amplify specific signals that are used to boost specific frequencies.

2nd Generation (Transistors)

It became faster, smaller, highly reliable, and significantly cheaper than vacuum tubes.

3rd Generation (Integrated Circuit)

• Sometimes referred to as a "semiconductor chip," the integrated circuit is a collection of transistors integrated and compacted into a single chip.

• Keyboards and mice had been used as inputs.

• See Moore's Law for reference.

4th Generation (Microprocessors)

• Computers in this generation were characterized by a significant increase in the number of transistors integrated into a single chip and by the invention of the microprocessor.

• The aim of inventing the new processor was to use it for the development of calculators.

5th Generation (Artificial Intelligence [AI])

VLSI (Very Large Scale Integration) technology in this generation became ULSI (Ultra Large Scale Integration) technology, resulting in the production of microprocessor chips having ten million electronic components.

Microprocessor

It is composed of integrated circuits that hold thousands of transistors responsible for processing the unique set of instructions and processes.

Central Processing Unit (CPU)

It is responsible for accepting data from input devices, processing the data into information, and transferring the information to memory and output devices.

Arithmetic Logic Unit (ALU)

As the name implies, its function is to perform arithmetic operations, such as addition, subtraction, division, and multiplication, and logic operations such as AND, OR, and NOT.

Control Unit (CU)

Its function is to control the input and output devices, generate control signals to the other components of the computer such as read and write signals, and perform instruction execution.

Registers

It is the fastest memory in a computer that holds information.

Main Memory

This device is capable of storing information temporarily.

Clock

It refers to a microchip that regulates the timing and speed of all computer functions.

Input/Output Devices

These are any hardware used to communicate with a computer.

Input/Output Interfaces

These are physical devices, ports, or connections that interact with the computer or other hardware devices.

Direct Memory Access

It is a feature of some computer bus architectures that allows data to be sent from a storage device to memory without using the CPU.

Bus

It is a pathway of data or instruction from one (1) element to the other.

Data Bus

This bus is used to carry data to and from the memory.

Address Bus

This bus defines the number of addressable locations in a memory IC.

Control Bus

This bus carries control signals from the control unit to the computer components in order to control the operation of each component.

Registers

A processor register provides the fastest way for a CPU to access data. Modern computer
architectures operate on the principle of moving data from the main memory into registers, and vice versa.

General-Purpose Registers / Accumulator

These store any transient data required by the processor.

Program Counter Register / Instruction Pointer

This holds the address of the current instruction being executed.

Memory Address Register

This holds the address of a memory location.

Memory Data Register

This holds a data value that is being stored to or retrieved from the memory location currently addressed by the memory address register.

Status Registers / Flags

These are used to allow the computer to keep track of special conditions such as arithmetic carry and overflow, power failure, and internal computer error.

CPU Architecture

Generally, an architecture defines what an object looks like, behaves, processes, and responds. In the aspect of computers, it defines how a processor operates through hardware/software and how it is being handled by the user.

Von Neumann Architecture

• It is a program consisting of code (instructions) and data.

• It uses a data bus to transfer data and instructions from the memory to the CPU. Memory holds both programs and data.

• It is still the standard architecture for all computers and computer-based devices.

Harvard Architecture

• It uses separate buses for instructions and data.

• The instruction address bus and instruction bus are used for reading instructions from the memory.

• The address bus and data bus are used for writing and reading data to and from the memory.

Instruction Set Architecture

It allows communication between the hardware component and the software component of a computer. It is a group of commands for a CPU in a machine language.

Complex Instruction Set Computer

It is a computer where single instructions can execute several low-level operations (such as a load from memory, an arithmetic operation, and a memory store) or can do multi-step operations or address modes within single instructions. Example: x86-x64 processors (Intel)

Reduced Instruction Set Computer

It is a computer which only uses simple instructions that can be divided into multiple instructions and perform low-level operations within a single clock cycle. Example: ARM (iPhone)

Fetch

It is designed to fetch several instructions at a time in parallel.

Decode

It identifies the opcode in which it determines the type of instruction. 

Execute

It executes the part/s for each different instruction.

Parallel Processing

It is a method of simultaneously breaking up and running program tasks on multiple microprocessors, thereby reducing processing time. It can be accomplished via a computer with two (2) or more processors or via a computer network. It induces problems resulting in not being synchronized.

Pipelining

It is the process accumulating and executing computer instructions instructions and tasks from the processor via a logical pipeline. It allows storing, prioritizing, managing, and executing tasks tasks and instructions in an orderly process.