What is inside of a microcomputer
The nerve centre of a microcomputer is the
central processing unit. This unit is built into a
microprocessor chip – an integrated circuit –
which executes program instructions and
supervises the computer’s overall operation. The
unit consists of three main parts.
The control unit, which examines the
instructions in the user’s program, interprets
each instruction and causes the circuits and the
rest of the components – disk drives, monitor, etc
– to be activated to execute the functions
specified.
The arithmetic logic unit (ALU), which
performs mathematical calculations (+, -, etc.)
and logical operations (and, or etc.).
The registers, which are high-speed units of
memory used to store and control information.
One of these registers is the program counter
(PC) which keeps track of the next instruction to
be performed in the main memory. Another is
the instruction register (IR) which holds the
instruction currently being executed.
One area where microprocessors differ is in the
amount of data – the number of bits – they can
work with at a time. There are 8, 16, 32 and 64
bit processors. The computer’s internal
architecture is evolving so quickly that the new
64-bit processors are able to address 4 billion
times more information than a 32-bit system.
supervise = επιβλέπω, επιστατώ
execute = εκτελώ
function = λειτουργία
interpret = ερμηνεύω
activate = ενεργοποιώ
evolve – εξελίσσομαι
demanding = απαιτητικός
The programs and data which pass through the
central processor must be loaded into the main
memory (also called the internal memory) in
order to be processed. Thus, when a user runs an
application, the microprocessor looks for it on
secondary storage devices (disks) and transfers a
copy of the application into the RAM area. RAM
(random access memory) is temporary i.e. its
information is lost when the computer is turned
off. However, the ROM section (read only
memory) is permanent and contains instructions
needed by the processor.
Most of today’s computers have internal
expansion slots that allow users to install
adapters or expansion boards. Popular adapters
include high resolution graphics boards, memory
expansion boards, and internal modems.
The power and performance of a computer is
partly determined by the speed of its
microprocessor. A clock provides pulses at fixed
intervals to measure and synchronize circuits and
units. The clock’s speed is measured in MHz
and refers to the frequency at which pulses are
emitted. For example, a CPU running at 500
MHz (500 million cycles per second) is likely to
provide a very fast processing rate and will
enable the computer to handle the most
demanding applications.
load - φορτώνω
process = επεξεργάζομαι
transfer = μεταφέρω
adapter = προσαρμογέας
expansion = επέκταση
interval = διάστημα που μεσολαβεί
emit = εκπέμπω
Read the text and decide whether the sentences that follow are true or false. Rewrite the false sentences
to make them true.
1.
2.
3.
4.
The CPU directs and coordinates the activities taking place within the computer system. ?
The arithmetic logic unit performs calculations on the data. ?
32-bit processors can handle more information than 64-bit processors. ?
A chip is an electronic device composed of silicon elements containing a set of integrated circuits.
?
5. RAM, ROM and secondary storage are the components of the main memory. ?
6. Information can not be processed by the microprocessor if it is not loaded into the main memory.
?
7. Permanent storage information is provided by RAM (random access memory). ?
8. The speed of the microprocessor is measured in megahertz. One MHz is equivalent to one million
cycles per second. ?
Write the opposites
high-speed - ?
permanent - ?
secondary - ?
cause - ?
next - ?
internal - ?
turn off - ?
install - ?
likely - ?
Relative clauses.
We can define people and things with a defining clause.
 The teacher who is responsible with the computer centre has just arrived.
We use the relative pronoun ‘who’ because it refers to a person. We can also use ‘that’.
 The microprocessor is a chip which processes the information provided by the software.
We use the relative pronoun ‘which’ because it refers to a thing, not a person. We can also use ‘that’.
 The computer we saw at the exhibition runs at 2400 MHz.
Relative pronouns can be left out when they are not the subject of the relative clause
Join the sentences
1. That’s the CPU. I’d like to buy it. ?
2. The microprocessor is a chip. It processes data and instructions. ?
3. The microprocessor coordinates activities. These activities take place in the computer system. ?
4. Last night I met someone. He works for GM as a computer programmer. ?
5. A co-processor is a silicon chip. It carries out mathematical operations at a very high speed. ?
6. A megahertz is a unit of frequency. It is used to measure processor speed. ?
7. Here is the floppy disk. You lent me it last week. ?
Which components of the computer are described below?
A round plastic surface that is coated with magnetic
film. They come in 3.5 inch size.
They hold about 720 kB to 1440 kB of information. They
typically are used to install new software, save, share, and/or
copy files. These drives are given letters. Commonly It is A.
If there is a second drive of this type it would be drive B ?
They function much like hard drives in that they
store large amounts of memory. What separates them is their
mobility and optical storage technology. Their storage
capacity is also very limited compared to hard drives. The can
only hold up to approximately 650 MB of information. The
other big difference is that you have to have a special drive
called a CD writer or burner to write on them. Otherwise they
can only be read. ?
Etch = To impress, delineate, or imprint clearly:
Pit = A natural or artificial hole or cavity
A stack of round metal platters called disks encased in
a metal air tight shell. They commonly range in sizes from 20
to 1 terabytes (1000 GB=1TB). The hard drive's function is to
store all the files, and software the computer will ever use.
Any file or software program used by RAM most likely will
come from this drive. The hard drive is commonly lettered as
the C drive. ?
They are similar to CD in that they are written and read
by laser. Although hard drives use magnetic currents store
data, these use light (laser) to write and read data on a disk.
These long and short pits are then stored or etched on the
surface of the disk. They can only be read by laser
technology. The new technology increased the amount of
memory a regular CD can hold. They can range in sizes from
4.34GB (1000MB=1GB) to 7.95GB. ?
Complete the text with the missing word
? of the best features ? a computer is the ability to give the computer commands and feed ?
information. Without an input device ? would not be possible. Input devices can ? built into the
computer ? it can be connected to the computer ? a cable. The most common input device ? the
keyboard. There are lots of others ? : mice, trackballs, touch pads, touch screens, pens, joy sticks,
scanners, bar code readers, video and digital cameras, and microphones. In addition, storage devices such
as disk drives can serve ? input devices.
Label this diagram with the correct terms.
computer
system
programs
and data
?
mechanical and
electronic equipment
?
?
The ‘brain’ of
the computer
?
physical units attached to the computer
Main memory
storage
devices
?
input/output
devices
ROM
?
?
?
?
?
` ?
?
Now study the diagram and complete the text.
A computer system consists of ? parts: the ? and the ? . The software is the information in the
form of ? and ? instructions. The hardware components are the ? and ? parts of the system.
The basic structure of a computer system is made up of three main hardware sections: (i) the ? , (ii) the
main ? , and (iii) the ? .
The ? is a microprocessor chip which executes program instructions and coordinates the activities of
all other components. In order to improve the computer’s performance, the user can add expansion cards
for video, sound and networking.
The ? holds the instructions and data which are currently being processed by the CPU.
The internal memory of a microcomputer is usually composed of two sections: ? and ? .
The ? are the physical units attached to the computer. They include ? devices as well as ?
devices. ? devices enable us to present information to the computer; for example, the ? and the
mouse. ? devices allow us to extract the results from the computer; for example, we can see the output
on the ? or in ? form. Secondary storage devices such as floppy, hard and ? disks are used to
store information permanently.
1. Computers perform mathematical operations.
?
2. Computers carried out financial transactions
?
3. I have used the automatic cash dispenser to draw out money.
?
4. Computers can store a large amount of information.
?
5. Computers have provided access to large data bases.
?
6. We also use computers to test materials.
?
7. Computers are controlling the radar systems in this airport.
?
8. I have destroyed the CPU.
?