TPRS THEORY 101 – COMPUTERS
A basic computer system comprises of the following:
1. Hardware
2. Software
3. Communications
4. People
Four operations of a computer system:
1. Input
2. Processing
3. Storage
4. Output
Types of computers:
Desktop
Laptop/Notebook/Tablet
Server
Mainframe
BASIC COMPUTER HARDWARE
The four essentials of a basic computer hardware system are:
1. Motherboard
2. CPU (Central Processing Unit)
3. Memory
4. Hard Drive
These components are usually housed in a case, and connected to common input and
output devices such as a mouse, keyboard, monitor or printer.
Each component of hardware is related to one (or sometimes two) of the functions of a
computer:
- Input
- Processing
- Storage
- Output.
1
A. PROCESSING DEVICES:
1. Motherboard - The motherboard is the foundation. All computer components,
internal and external, attach or connect to the motherboard. The motherboard is
like the central nervous system and skeleton of the human body - It provides
support for the internal components and also passes information between the
computer parts.
2. CPU (Central Processing Unit) - The CPU is the brain of a computer. It performs
most of the mathematical calculations required for the operation of a computer.
Other components may also have their own processors, but their results still
have to be passed through the CPU. The speed of the computer is usually
measured by the speed of the CPU. Even though other factors also affect overall
speed, the CPU rating is generally seen as the most important measure of
performance. Modern CPUs are usually rated between 2.0 GHz and 3.0 GHz,
although each passing month will see increasing performance. This measurement
refers to the number of calculations the processor can make in one second (1
MHz = 1 million cycles/sec). Generally speaking, the higher the number, the
faster (better) the processor. CPUs generate a lot of heat doing this work, and
require a heat sink and fan to keep them from overheating.
2
3. Computer Memory - RAM (Random Access Memory) is the part of the
computer that stores information the computer needs while it is operating, all
the data contained in RAM is lost when the computer is turned off. It is Random
Access because the computer can get the data in any order, not necessarily the
order in which it is stored. Generally speaking, the more RAM the better.
Anywhere from 4 to 16 gigabytes of RAM is common for memory.
ROM (Read-Only Memory) is a type of "built-in"
memory commonly found on the motherboard and other hardware devices. The
information stored in ROM is retained even when the device is turned off.
B. STORAGE DEVICES:
1. Hard Disk Drive (HDD) - A hard drive (Or hard disk drive) is used for the permanent
storage of digital information. Data is stored magnetically using rigid, rapidly
rotating disks. HDD's are commonly used in capacities ranging between 500 GB's and
2 terabytes (TB).
2. SSD (Solid-State Drive) - A solid-state drive uses interconnected flash memory chips
(solid-state memory) for the storage of data. An SSD requires significantly less power
than an HDD, while providing much greater read/write data speeds. These drives are
still very expensive in comparison to HDD's, and so capacities ranging between
128GB and 512GB are commonly used.
3. USB Flash Drive
4. External Hard Drive
5. SD Card
6. CD/DVD
3
C. INPUT DEVICES:
1. Keyboard - The most common/obvious device for entering information into a
computer is the keyboard. Made up of five areas containing: 1. Typewriter keys, 2.
Numeric keypad, 3. Navigation keys, 4. Function keys, 5. Special keys
2. Mouse - Another very common input device. Usually consists of two buttons (left
and right click), and a scroll wheel
3. Scanner - Can read media and images, Converts the image into binary code (digital
information) and thus provides input
4. Memory Card Reader - Allows for the transfer of information to and from various
memory card types. It allows for the reading/writing to commonly used SD, Micro-SD
and CF cards.
5. CD/DVD drive
6. Digital Camera
D. OUTPUT DEVICES:
1. Monitor - Is an electronic visual display for computers. It displays the computer
output on a screen. CRT (Cathode ray tube) driven monitors have largely been
replaced by LCD and LED display technology. The commonly used aspect ratio has
changed from 4:3 to 16:9 (and 16:10)
2. Printer - Prints computer output onto paper and other physical mediums.
3. Projectors
4. 3D Printer
5. Laser Cutter
E. INPUT/OUTPUT DEVICES:
Some devices are both input and output devices.
1. Modem/Router - information can go both ways over the line, is both an input
and output device.
2. Network Card connected to a network
3. Touchscreen monitor
4. Audio interface – can receive audio signals from mic and line inputs and send
audio signals to monitor speakers
4
COMPUTER DISPLAYS
The monitor is often a passive device that just displays the video output from the system.
However, so much data is needed for the constantly changing screen display that special
provisions are made for it.
The video card (or video circuitry on the motherboard [onboard graphics adaptor]), has its
own RAM memory just to hold the display information, and its own ROM BIOS to control the
output.
Some motherboards use a high speed connection between the CPU and the video card.
AGP (Accelerated Graphics Port), a high-end standard ten years ago has been progressively
phased out in favour of PCIExpress or PCIe.
The important details to consider when evaluating a screen display are how many distinct
colours can be displayed and the screen resolution. Resolution refers to the number of
pixels the image contains vertically and horizontally. Each dot of colour making up the image
is one pixel.
Through the evolution of video technology there has been a number of standards, each with
its own set of initials for e.g. CGA (Colour Graphics Adapter), EGA (Enhanced Graphics
Adapter), VGA (Video Graphics Array) or SVGA (Super Video Graphics Array), has a
resolution of 800 x 600. Some higher performance monitors support SXGA (Super Extended
Graphics Array) (1280 x 1024), UXGA (Ultra Extended Graphics Array) (1600 x 1200) and
FHD (Full High Definition) (1920 x 1080), which is quickly becoming standard, and higher.
PORTS
There are physical connections on the back (and front) of the computer that are called
ports, and various devices connect to the computer through cables attached to these ports.
1. Serial Port - The most basic of these connections. Data travels over a single signal
line as a series of bits, one right after the other. Serial port connectors have either 9
or 25 pins, with a male connector on the back of the computer and a female
connector on the cable. The 9 pin version is more common, and was previously used
to connect a mouse. Serial ports are also called communication ports as they are bi-
directional. i.e. They allow each device to receive data as well as transmit it.
2. Parallel Port - Has 8 parallel signal lines. Transmits 8 bits at a time. The computer has
a 25-pin female connector on the back (so as not to be confused with the 25-pin
male serial connector). Most often used to connect a printer.
3. Universal Serial Bus (USB) - Has come to support a large range of devices from
printers to hard drives. Referred to as a bus because several devices can be
connected on the same cable, but is also a port because data goes into and out of
the computer system via its connector. Many devices have plug-and-play capabilities
enabling easy installation. USB devices are ‘hot-swappable’ meaning they can be
5
connected and disconnected at any time, without having to restart the machine.
From its introduction in the mid 90’s with USB 1 to the introduction of USB 2 in 2000,
and later USB 3 in 2008 data transfer rates have increased rapidly.
4. FireWire or IEEE 1934 - Similar to USB, but with far greater capabilities. It has plug & play and hot-sw
capabilities. Provides power through the cable. Commonly used for connecting
digital camcorders and external hard drives to a computer.
FireWire 800 Connector and FireWire 400 Connector.
5. DVI (Digital Visual Interface) - DVI is one of the most common digital video cables
you’ll see on desktops and LCD monitors. It’s the most similar to VGA connectors,
with up to 29 pins and support for analog as well as digital video. DVI can stream up
to 1920×1200 HD video, or with dual-link DVI connectors you can support up to
2560×1600 pixels. The DVI interface has proven to be extremely versatile; its two
connectors provide manufacturers with the flexibility to support digital devices while
remaining backwards compatible with analogue devices.
6. HDMI (High-Definition Multimedia Interface) - HDMI technology is the industry-
leading interface and de-facto standard connecting high-definition (HD) and ultra
high-definition (UHD) equipment, from HDTVs and personal computers to cameras,
camcorders, tablets, Blu-ray players, gaming consoles, smartphones, and just about
any other device capable of sending or receiving an HD signal. HDMI cables can
stream digital video and audio simultaneously over the same cable. HDMI cables
support up to 1920×1200 HD video and 8 channel 192 kHz uncompressed digital
audio.
7. Thunderbolt - Thunderbolt technology gives you access to a world of high-speed peripherals and
high-
6
resolution displays via one simple port and a cable that carries both DisplayPort and
PCI Express data.
7
Thunderbolt gives you two channels on the same connector with 10Gb/s of
throughput in both directions. Ultrafast, ultra flexible Thunderbolt 2 increases that to
20Gb/s. You can move data to and from peripherals up to 40 times faster than with
USB 2 and up to 25 times faster than with FireWire 800. You also have more than
enough bandwidth to daisy-chain multiple high-speed devices without using a hub or
switch. For example, you can connect several high-performance external disks, a
video capture device, and even a display to a single Thunderbolt chain while
maintaining maximum throughput.
OVERVIEW
