Ver, having to use special paper adds to the running costs and is

often inconvenient.

Another type of non-impact printer is an ink-jet printer. It

operates by firing a fine spray of quick-drying ink at the paper.

The ink jet is formed into the required character by electrosta-

tic fields. This type of printer is quite fast and can print at

rates of up to about 400 cps.

All the above types of printers are known as character prin-

ters because they only print one character at a time. They are

also consider to be alow printers in computer terms.

Mainframe computers need printers that are very fast. These

fast printer include line printer and laser printers.

- 25 -

Line printers may be impact or non-impact types. Impact

line printers have solid characters on a moving chain or rotating

drum but non-impact line printers use electrostatics to form the

ink into the shapes on the characters. Line printers print a line

of text at a time and can have print rates of about 3,000 lines

per minute (3,000) lpm. However, they are very expensive.

Laser printers are extremely fast, printing a complete page

at time. They are non-impact printers which form an image on a

light sensitive drum by scanning it with a laser beam. The image

is then transferred to paper using special powdered ink. They can

have a print rate of about 20,000 lpm but they are very expensive.

These are only a few of the many types of printers availab-

le. The techniques used by these printers are constantly being

improved.

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДВДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДї

і Impact і Non-impact і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

і S і і

і l і і

і o і і

і w і і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

і F і і

і a і і

і s і і

і t і і

АДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДБДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

Task 3

Solve these problems in pairs. What kind of printer would

best suit each of these requirements ?

1. A small business which wants to produce letters directly from

- 26 -

the computer of a quality good enough to send to customers.

2. An engineering firm who want rough copies of diagrams and text

for use within the company.

3. A company who required quite a fast printer for their minicom-

puter which does not need special paper and which will not

disturb the work of the office.

4. A major insurance company who need to produce large quanities

of high quality text from their mainfram computer. They would

prefer a silent device.

5. A mail-order company who want to produce large quantities of

letters to their customers. They have a mainfram computer with

a special print room and therefore don`t have to worry about

noise.

Task 4

The Table below lists some of the input and output devices

you have studied in this unit and the previous unit.

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДВДДДДДДДДДДДДДДДДДДДДДДДДДДДДДї

і Input device і Application і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

і1 numeric keypad і input mathematical data і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

і2 mouse і controls cursor і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

і3 lightpen і і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

і4 joystick і і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

і5 voice recognition deviceі і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

і output device і і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

і6 high resolution monitor і і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

і7 low resolution monitor і і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

- 27 -

і8 daisywheel printer і і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

і9 laser printer і і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

і10 non-impact printer і і

АДДДДДДДДДДДДДДДДДДДДДДДДДДБДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

Add to table the correct application for each device from

this list. Number 1 has been entered for you as an example.

a draw on the screen

b control computers by speech

c display high-quality graphics

d input mathematical data

e print `letter quality` text

f play fast action games

g print text silently

h print text very quickly

i select a process easily from a menu

j display text and xrude graphics

Task 5

We can linke a device and its application in two ways.

For example,

1. A numeric keyboard is used to input mathematical data.

2. A numeric keyboard is used for inputting mathematical data.

Describe the applications of each device listed in the Table

above in the same way.

Task 6

Many terms used in computing consist of two nouns, for

example, lightpen. The first noun describe the second noun in a

number of ways.

Study these examples.

- 28 -

1 lightpen a pen which is sensitive to light

2 bar code a code which is made up of printed bars

3 graphics tablet a tablet which is used for drawing graphics

4 drum plotter a plotter which has a drum

Try to define each of these terms in the same way. When you

have finished, check your answers in Appendix 1.

1 touchpad 6 impact printer

2 storage device 7 daisywheel printer

3 flatbed plotter 8 disc drive

4 laser printer 9 voice recognition device

5 colour monitor 10 line printer

Writing

Study these facts about printers.

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДВДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДї

і Impact і Non-impact і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

і mechanical contact between і no mechanical contact between і

і print head and paper і print head and paper і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

і noisy і silent і

ГДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДґ

іe.g. daisywheel і e.g. thermal і

АДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДБДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

Note how we can classify printers.

Printers can be divaded into inmpact and non-impact printers.

Note how we can contrast these two types.