Computer Systems L1.1&1.2

Notes for lectures 1.1 and 1.2

What is the fundamental difference between computer hardware and software?

Hardware is the physical components of a computer, while software is the programs that run on the computer.

What is the primary role of an Operating System (OS)?

To manage computer hardware and software resources and provide common services for computer programs.

List the three most common number systems used in computers.

Decimal (Base 10), Binary (Base 2), and Hexadecimal (Base 16).

What are the first four column values (powers of 2) in the binary system, starting from 2^0?

1, 2, 4, 8 (2^0, 2^1, 2^2, 2^3).

Describe the process of converting a Decimal number to Binary.

Repeatedly divide the decimal number by 2 and record the remainder. Read the remainders from bottom to top to get the binary equivalent.

What is the main characteristic and drawback of the Positional Method for Binary to Decimal conversion?

Characteristic: It is a safe method that involves summing the column values where the digit is 1. Drawback: It can become difficult to use as the binary number length increases.

Explain the steps of the Doubling Method for Binary to Decimal conversion.

Start with an initial total of zero. For each digit (left to right), double the previous total and add the current binary digit (0 or 1).

Why is Hexadecimal used in computing if computers only understand Binary?

t makes large binary numbers (like memory addresses) more compact, readable, and easier for humans to manage and memorize.

What is the base of the Hexadecimal number system?

Base 16.

How many bits of Binary information are represented by a single Hexadecimal digit?

Four bits (a nibble).

What are the digits used in Hexadecimal?

0-9 and the letters A, B, C, D, E, F.

Describe the core steps for converting Binary to Hexadecimal.

Split the binary number into 4-bit groups and assign one corresponding hexadecimal digit to each group.

When converting Decimal to Hexadecimal, what number do you repeatedly divide by?

16 (the hexadecimal base value).

What are two common application areas where Hexadecimal numbers are used?

Computer memory addresses and HTML colour references.

What is a Hex Editor primarily used for in digital investigations?

To visualize and edit the underlying hexadecimal code of files for tasks like extracting metadata or verifying authenticity.