Chapter 4: Computer Architecture

What is a computer architecture?
A computer architecture is made up of all the parts of a computer system that are necessary for it to function. This includes the operating system, memory chip, logic circuits, storage devices, input and output devices, security components, buses, and networking interface.

The Central Processing Unit (CPU):

• The brains of a computer.
• It fetches instructions from memory and executes them.
• It's a piece of hardware with it's own instructions set that is used to carry out tasks.
• Each CPU has a specific architecture and set of instructions.
• Operating systems have to be designed to work within CUP architecture because it has to be able to "speak the language" of the processor (processor's instruction set).

How does the CPU work?

• There is a chip within the CPU that is only a couple of square inches.
• The chip contains millions of transactions.
• All operations within the CPI are performed by electrical signals that work in different voltages in different combinations. 
• The different voltages are held in transistor that represent 0's and 1's to the operating system. 
• Registers contained in the CPU point to memory location which houses the next executable instruction. 
• A register is a temporary storage location that holds the information that tells the CPU what it's next job is. 
• Actual execution of the instructions is done by the arithmetic logic unit (ALU) with is considered the brain of the CPU.
• ALU performs mathematical functions and logical operations on data.