Java Reference
In-Depth Information
Answers to Self-
Chapter 1
Introduction
1.1 Computer Processing
SR 1.1
The hardware of a computer system consists of its physical components
such as a circuit board, monitor, or keyboard. Computer software con-
sists of the programs that are executed by the hardware and the data
that those programs use. Hardware is tangible, whereas software is
intangible. In order to be useful, hardware requires software and soft-
ware requires hardware.
SR 1.2
The operating system provides a user interface and efficiently coordi-
nates the use of resources such as main memory and the CPU.
SR 1.3
It takes 7,200,000 numbers for a 3-minute song (40,000
60
3) and
144,000,000 numbers for 1 hour of music (40,000
60
60).
SR 1.4
The information is broken into pieces, and those pieces are represented
as numbers.
In general, N bits can represent 2
N
unique items. Therefore:
SR 1.5
a. 2 bits can represent 4 items because 2
2
4.
b. 4 bits can represent 16 items because 2
4
16.
c. 5 bits can represent 32 items because 2
5
32.
d. 7 bits can represent 128 items because 2
7
128.
SR 1.6
It would take 6 bits to represent each of the 50 states. Five bits is not
enough because 2
5
32 but six bits would be enough because 2
6
64.
1.2 Hardware Components
SR 1.7
A kilobyte (KB) is 2
10
= 1,024 bytes, a megabyte (MB) is 2
20
1,048,576
bytes, and a gigabyte (GB) is 2
30
1,073,741,824 bytes. Therefore:
735
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