Fundamentals of computers

Q. 1. (a) What is the relation between address bus and memory capacity of a computer system.
Ans. Memory is used for storing the data & information. After processing every data or information are
stored in memory. Memories are of two types:
1. Main memory
2. Secondary Memory.
1. Main memory is temporary memory device which is used for temporarily storage.
2. Secondarymemoryispermanentmemorydevicewhichisusedforpermanentstoragelike,floppydisk,
CD-ROM etc.
Computer memories have some capacity of a computer system.

There are another fastest memory which is used for storing the information or data i.e. cache memory.
Q. 1. (b) Briefly describe any one printer.

Ans. Printer : Printer is the most important output device, which is used to print information on paper.
Types of Printers: Printers are mainly classified into two different types of printer:
1. Impact printers 2. Non-Impact printers
Impact Printers: The printers that print the character by striking against the ribbon & onto the paper, are
called impact printers. These printers pare of two types :
(i) Character & (ii) Line printers.
Non-Impact Printers : The printers that print the characters without striking against the ribbon & onto
the paper are called non-impact printers, like (i) Laser printers, (ii) Inkjet printer (iii) Thermal printer.
Impact Printers : DOT MATRIX PRINTER (DMP): One of the most popular category of printers in
market, mainly because of their case of printing feature & economical price is Dot Matrix printer. Each character
printed is in form of pattern of DOTs & head consists of a Matrix of pins of size (5 x 7,7 x 9,9 x 7 or 9 x 9)
which comes out of form a character, that is why it is called Dot-Matrix Printer. Printer head moves on a carriage.
Paper is sandwitched between ribbon & head. Say 'A' is to be printed, then pins corresponding to 'A' moves
out. Strike the ribbon & 'A' is printed. For printing, the whole line a buffer (temporary storage) of size equal to
the size of paper is used. A paper of width 80 columns, a buffer of 80 characters is used. The way of printing,
always in one direction from left to right is called unidirectional. New printers print bidirectionaliy which is
achieved as : first line is printed starting from first position of buffer storage, as soon as first character in
printed, 80th character of next line is stored in it & so on. After printing one, line, head starts printing from right
to left using buffer positions from 80th to first again. Thus, it prints in both direction.
DMP are available in two sizes as 80 column & 132 column Printing speed varies from 200 to 360 cps
character per second.