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Current Instruction Register, this register stores the current instruction being decoded anf executed.

Accumulator, this register is used when carrying out ALU calculations; it stores data temporarily during the calculations.

Memory Address Register, this register stores the address of the memory location currently being read from or written to

Memory Data Register, this register stores data which has just been read from memory or data which is about to be written to memory

Program Counter, this register stores the address where the next instruction to be read can be found

Control Unit (CU) Arithmetic and Logic Unit (ALU) Register and buses

Arithmetic and Logic Unit, allows the required arithmetic to perform operations such as addition and subtraction or logical operations such as AND, OR, and NOT to be carried out while a program is being run

The control unit reads an instruction from memory. The address of the location when the instruction can be found is stored in the Program Counter (PC). This instruction is the interpreted using the Fetch-Decode-Execute

A system clock is used to produce timing signals on the control bus to ensure this vital synschornisation takes place, without the clock, the computer would crash

CIR, MDR, PC, ACC, MAR

Serial data transmission is when a data is being sent at one bit at a time over a single wire

Parallel data transmission is when data is sent at several bits at a time through several wires

Serial is reliable over long distance while Parallel is better over short distance. Serial is less expensive than parallel due to fewer hardware requirements. Parallel is preffered when speed is important. Serial, transmited bits wont have the risk of being skewed because data is transmiteted only though 1 wire. While parallel the transmitted bits have a higher chance of being skewed due to data being transmitted over several wires

One direction only not at the same time example computer to printer

Both direction but not at the same time example walkie talkie

Both direction at the same time example broadband internet connections like streaming

2 types of light projectors, digital light projectors and liquid crystal display

Projectors are used to project computer output onto larger screens. Digital light projectors use rgb colours

Advantages: - Higher contrast ratio - Higher reliability/longivity - Quieter running than LCD projector - uses a single DMD chip, which means no issue lining up the images - Smaller and lighter than LCD projector - they are better suited to dusty or smoky atmosphere than LCD projectors

Disadvantages: image tends to suffer from ‘‘shadow’ when showing a moving image - DLP do not have grey components in the image - the colour definition is frequently not as good as LCD projectors because the colour saturation is not as good (colour saturation is the intensity of a colour)

Advantages: - It gives a shaper image than DLP projectors - have better colour saturation than DLP projectors - more efficient in their use of energy than DLP technology - consequently they generate less heat.

Disadvantages: - Although improving, the contrast ratios are not as good as DLPs - LCD projectors have a limited life (longtivity is not as good as DLP projectors) - since LCD panels are organic in nature, they tend to degrade with time, the screen turns yellow and colours are degraded over time

They use liquid ink, they are usually used for printing one off photos or where only few pages of good quality, colour printing is needed

They use powder ink, for documents since they are fast or any printing that requires a high volume printing Advantages: - They have a large toner cartridges and large paper trays