Introduction to computer systems
Input and output devices:
Input hardware consists of devices that translate data into a form the computer can process. The way the computer reads our input consists of binary 0s and 1s. For example, each button on a keyboard relates to a particular item or function. Buttons can be labelled with text or an icon that corresponds to that function.
Output hardware devices consist of devices that translates information processed by the computer into a form the user can understand example of an output device include a computer monitor, and speakers, which can receive data.
Central processing unit (CPU):
The CPU (Central Processing Unit) is the part of the computer system that is commonly referred to as the “brains” of a computer. The CPU is also known as the processor or microprocessor.
The CPU is responsible for executing a sequence of stored instructions called a program. This program will take inputs from an input device, process the input in some way and output the results to an output device.
In the CPU, the primary components are ALU (Arithmetic Logical Unit) that performs mathematical, logical, and division operations and the CU (Control Unit) that directs all of the processor’s operations.
All sorts of devices use a CPU, including desktop, laptop, and tablet computers, smartphones even some televisions.
Random access memory (RAM)
RAM is an acronym for “Random Access Memory.” It is a memory device typically in a chipset. It is used processes to access and temporarily store needed memory assists, so processes can be done. A common explanation for ram is the “counter space “metaphor so a computer is like a kitchen at a restaurant. The computer’s processor is like a chef, who works to prepare food. The faster the chef, the faster food is ready. The computer’s RAM is like counter-space. Everything in RAM is easy for the processor to get at, so if you have a lot of counter space, the chef can work on preparing more things at once.
Basic Input Output System (BIOS) / Unified Extensible Firmware Interface (UEFI)
A computer only knows what to do if it has very clear instructions. Most of those instructions live on the hard disk and are loaded from the hard disk when required. But the very first thing your computer needs when you turn it on is instructions which are kept inside the computer itself. It is the very first thing that runs when you turn the computer on, and it tells the computer how to boot up, as well as some other very basic things. It also contains instructions for how to access the hardware, which other software can use. When software needs to access hardware, it will usually call the BIOS and set BIOS to actually talk to the hardware.
Usually alternatively referred to as a bus slot or expansion port, an expansion slot is a connection or port located inside a computer on the motherboard or riser board that allows a computer hardware card to be connected. For example, you’d purchase a video expansion card and install that card into the compatible expansion slot.
There are three types of expansion slots found in modern day computers these are the PCIe, AGP, and the ISA.
The PCIe is a type of expansion slot that communicates with the motherboard, and therefore with the microprocessor, both quickly and efficiently.
The AGP was a type of expansion slot specifically designed to deal with graphics adapters. In fact, AGP stands for Accelerated Graphics Ports. Older PCs may sport this expansion slot, but the best video cards use PCEes’.
The oldest type of expansion slot is the ISA, which stands for Industry Standard Architecture. ISA tend to be used for older expansion cards since they are more compatible.
Software is a collection of instructions that enable the user to interact with a computer, its hardware, or perform a certain task. Without software, most computers would be useless. For example, without your internet browser software, you could not surf the internet or read pages online and without an operating system, the browser could not run on your computer.
A device driver is a particular form of software application that is designed to enable interaction with hardware devices. Without the required device driver, the corresponding hardware device fails to work.
A device driver usually communicates with the hardware by means of the communications subsystem or computer bus to which the hardware is connected. Device drivers are operating system-specific and hardware-dependent. A device driver acts as a translator between the hardware device and the programs or operating systems that use it.
A device driver may also be called a software driver.
An application program is a program designed to perform a specific function directly for the user or, in some cases, for another application program. Examples of applications include word processors, database programs, web browsers, development tools, drawing, paint, image editing programs, and communication programs. Applications use the services of the computer’s operating systems and other programs that an application program uses is called the application program interface (API).
Operating Systems (OS)
The operating system is the most important program that runs on a computer. Every general-purpose computer must have an operating system to run other programs and applications. Computer operating systems perform basic tasks, such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories on the storage drives, and controlling peripheral devices, such as printers.
Example of operating systems includes Microsoft’s flagship Windows often used for home and business computers. Another example would be Apple’s Mac OS which is off the Macintosh line of personal computers and workstations.
For large systems, the operating system has even greater responsibilities and powers. It is like a traffic cop, it makes sure that differential programs and users running at the same time do not interfere with each other. The operating is also responsible for security, ensuring that unauthorized users do not access the system.
Smaller devices such as phones and tablets have operating systems allowing them to run applications and programs these operating systems being Google’s Android and Apple’s IOS.