Page 1104 - Basic Electrical Engineering

important large capacity storage (bulk storage) memory device used in
computers these days.

16.11.10 Digital Systems

Like any other system a digital system consists of a number of subsystems
assembled together to perform some specific task. In a digital system, the

sub-system may be adders, subtractors, counters, shift registers, RAMs or
ROMs. Subsystems are manufactured on a single chip of IC. Even the whole
system is made available on a single IC chip. Such digital integrated systems

are classified as SSI (small-scale integration), MSI (medium-scale
integration), LSI (large-scale integration), VLSI (very-large- scale

integration), and ULSI (utra-large-scale integration). A VLSI contains logic
gates ranging from 10,000 to 99,999. Your digital wrist watch, for example,

is an assembly of a number of digital subsytems on a single chip. The
calculator we use, if we open it, we will notice, contains a small pencil cell, a

mini read out display, key board from which few wires are attached to an IC
chip. The IC is an LSI chip which is intended to perform thousands of logic
functions consisting of storage, processing, and control that are required in a

calculating system.

16.12 REVIEW QUESTIONS

A. Short Answer Type Questions

1. State the advantages of digital signals over analog signals.
2. Differentiate between analog and digital signals. What are the disadvantages of analog
systems?
3. What are the different types of number systems? Explain each of them.
4. What is a binary number system. Mention its applications
5. Explain with example how binary numbers can be converted into decimal numbers.
6. Illustrate how decimal numbers can be converted into binary numbers.
7. Convert the following decimal numbers into binary numbers:

a. 49;
b. 756;
c. 0.578;
d. 110.58;