Data Representation (Part 2) Lecture Notes

Vocabulary flashcards covering hexadecimal uses, networking addresses, binary arithmetic, overflow, logical shifts, and two’s complement concepts.

Hexadecimal number system

A base-16 numbering system (digits 0–9 and A–F) used because it is more compact and readable than binary.

Error code

Automatically generated hexadecimal value that indicates the memory location where a computer error occurred.

Network Interface Card (NIC)

Hardware that connects a device to a network; its unique MAC address identifies the device.

MAC address

A unique device identifier written in six pairs of hex digits (NN-NN-NN-DD-DD-DD); first half = manufacturer, second half = serial number.

IP address

Numerical label assigned to a device on a network; can be IPv4 (32-bit) or IPv6 (128-bit).

IPv4

The 32-bit version of the Internet Protocol, usually written as four decimal numbers separated by dots (e.g., 192.168.1.1).

IPv6

The 128-bit version of the Internet Protocol, created to vastly expand the number of available addresses.

HTML colour code

A six-digit hexadecimal value (e.g., #FF0000) indicating the red, green and blue intensities for a screen pixel.

Hypertext Mark-up Language (HTML)

Standard language used to create webpages; employs hexadecimal codes to specify colours.

Binary addition

Adding binary digits column by column, producing a sum bit and possibly a carry bit.

Carry (binary addition)

A bit passed to the next column when the sum in a binary addition column equals 2 or 3.

Sum (binary addition)

The resulting bit in a binary addition column after accounting for any carry.

Overflow

Condition where an arithmetic result exceeds the maximum value the allotted word size can represent.

Overflow error

Error produced when a calculation generates more bits than the register can store (e.g., a ninth bit in an 8-bit sum).

Word size

The fixed number of bits (e.g., 8-bit, 32-bit) a computer uses to store numbers or instructions.

8-bit register

A storage location that holds exactly 8 bits, allowing unsigned values from 0 to 255.

Logical shift

Bitwise operation that moves all bits left or right, filling vacated positions with zeros.

Left shift

Logical shift that moves bits toward more significant positions, multiplying an unsigned binary number by 2 per shift.

Right shift

Logical shift that moves bits toward less significant positions, dividing an unsigned binary number by 2 per shift.

Most significant bit (MSB)

The left-most bit in a binary number; in two’s complement it also represents the sign/negative weight.

Two’s complement

Binary notation that represents positive and negative integers by letting the MSB carry a negative weight.

Bit inversion (one’s complement)

Flipping every bit (0→1, 1→0); first step in converting a positive binary number to its two’s complement negative.

Add-one method

Second step in two’s complement negation: add 1 to the inverted bits to obtain the negative value.

Denary

The base-10 (decimal) numbering system commonly used by humans.