The computer system
The computer system refers to all the parts that make up the computer, the hardware,
and the software. Hardware refers to all the physical components of a computer that we
can see and touch. On the other hand, software refers to all the programs that run the
hardware or allow users to use the computer for a specific function.
There are several examples of hardware in a computer system. They are broken down
into four main categories:
Input device
Output devices
Main Memory and Backing storage
The CPU
Input Devices.
These devices are used to input data or instructions into the computer. Examples
include the keyboard, mouse, joystick, touchscreen, light pen, etc. The input devices
can connect to the computer wirelessly or using a wire. The wire attaches the device to
the motherboard. The motherboard is a circuitry board that allows all the devices to
connect to the computer and communicate.
Output devices
These devices, on the other hand, are used to handle the results of processing. They
include printers, monitors, speakers, plotters, etc. Just like input devices, output devices
are connected to the motherboard of a computer.
Main Memory and backing storage
A typical example of the main memory is Random Access Memory (RAM). RAM is
where programs or instructions and data are stored whilst the computer is running. The
bigger the RAM size, the more data and programs it can handle and, consequently, the
faster the performance. But memory is not the only thing that determines the
performance of a computer. Other factors, such as the processor speed, the size of
cache memory, dedicated graphics card, etc., also significantly impact a computer's
performance.
Backing storage, on the other hand, is used for longer-term storage. Devices that
constitute backing storage include Hard Disk Drives (HDD), Solid State Drives (SSD),
memory stick, etc. More extensive programs like the Operating system are stored on
backing storage. When any parts of the operating system are required, it is loaded into
the main memory.
The CPU
This is the part of the computer system responsible for all processing on the computer.
It is made up of the Arithmetic and Logic Unit (ALU), the Control Unit (CU) and
registers. The ALU is responsible for all logical operations such as comparisons and
arithmetic operations such as addition, subtraction, etc.
On the other hand, the CU is responsible for the coordination of signals within and
outside the CPU. The registers are small, fast memories within the CPU used to hold
data or instructions about to be executed, or that has just been executed. There are
several of these registers inside the CPU. The most common ones are the Program
Counter (PC), Memory Address Register (MAR), Memory Data Register (MDR), Current
Instruction Register (CIR) and Accumulator (ACC).
A typical computer will have all these parts working together to form a computer system.
The picture shows a screenshot of a laptop taken from an image editing software called
name of software. We will continue to look at this topic in the coming days.