A-level Computer Science · OCR H446 · AQA 7517

Boolean Algebra & Logic

Everything the OCR and AQA specifications ask for on Boolean logic — gates, algebraic simplification, Karnaugh maps, adders and the D-type flip-flop — on five focused pages. Use the OCR / AQA switch in the header to flip all notation to your board.

Notation, your way. OCR writes AND/OR/NOT as A * B, A + B, ~A; AQA uses a dot, a plus and an overbar. The toggle changes every expression on the site at once and remembers your choice.

Start here

PAGE 1

Boolean Algebra

The six logic gates with truth tables, and the laws used to simplify expressions (De Morgan, distribution, association, commutation, absorption, double negation).

PAGE 2

Karnaugh Maps

A visual way to simplify expressions of 2–4 variables. Gray-code layout, grouping rules and a full worked example. OCR only

PAGE 3

Adders

The half adder and the full adder: truth tables, Boolean expressions and circuit diagrams — and how a full adder is built from two half adders.

PAGE 4

D-type Flip-Flop

The edge-triggered 1-bit memory cell: symbol, behaviour, timing and its role in registers.

What each board requires

How the pages map onto the specification. The content is the same for both boards; only the notation differs — except Karnaugh maps, which only OCR examines.

Topic	OCR H446 (1.4.3)	AQA 7517 (4.6.4 / 4.6.5)	Page
Logic gates & truth tables	Required	Required	Boolean Algebra
Boolean laws & simplification	Required	Required	Boolean Algebra
Karnaugh maps	Required	Not assessed	Karnaugh Maps
Half adder & full adder	Required	Required	Adders
D-type flip-flop	Required	Required*	D-type Flip-Flop

*AQA expects the D-type flip-flop as a memory unit; its internal construction is not examined.