# 3.3 Hardware

# 3.3.1 Logic gates and circuit design

### XOR and Half-Adder

This video starts by recapping the truth table for an exclusive-OR (XOR) gate, and then goes on to show how its properties can be used to help create a half-adder in conjunction with an AND gate. The video helps demystify the concept by building up the half-adder and explaining with examples why an additional gate is needed.

*Updated: 2015-04-29*

# 3.3.2 Boolean algebra

### Logic Simplification Examples Using Boolean Rules

This is an excellent video which goes clearly through the individual steps of simplifying Boolean expressions. The video starts with a clear list of simplification rules and explains why they work. There are then two examples, complete with logic circuit diagrams, which are worked through line by line until they are fully simplified. This is probably the clearest explanation of Boolean simplification I have seen. (The video is a lot better than the screenshot makes it look!)

*Updated: 2015-11-24*

# 3.3.3 Karnaugh Maps

# 3.3.4 Flip-flops

# 3.3.5 RISC processors

# 3.3.6 Parallel processing

### CERN Grid Computing system

This brief tour of the CERN computer grid gives a good overview of the computing system and the power available.

The second video features interviews with CERN employees who explain how the grid computing system works and how the data is transmitted to and processed by multiple tiers of computers spread across Europe.

*Updated: 2015-05-27*