Introduction to computer hardware

Understanding Computers and Systems Engineering

In the realm of technology, computers are indispensable tools that execute mathematical and logical operations with remarkable speed and precision. Initially, computers were primarily used for basic arithmetic operations, but today, their capabilities have expanded to encompass a wide array of tasks, including text processing and managing diverse forms of information such as text, images, sound, and video.

Types of Computers

Computers can be categorized into embedded and non-embedded types, with the former being integral components of other machines. Non-embedded computers are further classified based on their power, size, and speed, leading to the distinction between microcomputers, workstations, mainframes, and supercomputers.

• Microcomputers: Equipped with a microprocessor as the central processing unit, microcomputers consist of a microprocessor, memory, and input/output devices.

• Workstations: These high-end microcomputers are designed for technical or scientific applications, typically used by a single user and connected to a local area network.

• Mainframes: Operating at high speeds and possessing large storage capacity, mainframes are capable of handling the workload of multiple users.

• Supercomputers: Representing the pinnacle of computing power, supercomputers are utilized for specialized applications that demand extensive mathematical calculations, such as weather forecasting, animated graphics, and nuclear energy research.

Memory and Storage

The workspace of a computer, known as memory or RAM (Random Access Memory), serves as the primary storage area for application instructions and data during operation. The capacity of memory is a crucial factor, as larger memory translates to a more expansive workspace.

Memory Units

• Bit: The smallest basic unit of memory.

• Byte (B): Comprising 8 bits, the byte serves as the fundamental memory unit.

• Kilobyte (KB), Megabyte (MB), Gigabyte (GB), Terabyte (TB): These units represent increasing orders of magnitude in memory capacity.

Volatile and Non-Volatile Memory

Memory can be categorized as volatile or non-volatile. Volatile memory, such as Random Access Memory (RAM), loses its contents when the system's power is turned off or interrupted. Non-volatile memory includes various types such as Read Only Memory (ROM), Programmable Read Only Memory (PROM), and Flash memory, which retain data even when the power is off.

Input and Output Devices

Devices that provide data to a computer from the external environment, such as keyboards, mice, and scanners, are considered input devices. On the other hand, output devices produce information from a computer to the outside world, including printed reports, images, and sounds. Common output devices encompass monitors and printers.

Display Devices

Monitors, also known as display screens, visually convey information and are classified into two common types: CRT (Cathode Ray Tube) and LCD (Liquid Crystal Display). Key specifications for monitors include refresh rate, resolution, and visible screen size.

Printers

Printers produce hard copies or printouts of text and graphics on paper. Dot matrix, inkjet, and laser printers are among the common types, each with distinct mechanisms for creating printed images. 

Scanners

A computer scanner is a device that converts printed or transparent material into a digital image. The resolution of a scanner, typically measured in dots per inch (dpi), determines the sharpness of the scan. The internal electronics of a scanner perform analog-to-digital (A/D) conversion to convert color information into digital bits. Modern scanners often feature 48-bit A/D conversion, providing high-quality color reproduction.

Input and Output to Monitors

The video data from the processor is sent to the video card, which converts the digital output into an analog video signal. This signal is then transmitted to the CRT or LCD monitor, where it is processed to create the visual display.

Dot Matrix Printers

Dot matrix printers utilize hammers and a ribbon to form images out of dots. The resolution of the printed image is determined by the number of dot hammers used, with a higher number resulting in higher resolution.

Inkjet Printers

Inkjet printers contain an ink cartridge that houses the print head and ink supply. The printers produce extremely small dots, positioned precisely to achieve high resolutions of up to 1440 x 720 dots per inch. The dots can be combined to create photo-quality images.

Laser Printers

Laser printers utilize a complex process involving the charging of the drum, laser exposure, toner application, and fusing to produce high-quality prints. The laser reduces the negative charge on the drum, attracting toner to the paper, which is then fused to produce the final print.