Section 7 Flashcards
What is a processor in a computer?
A device that carries out instructions and memory management.
What does a processor do in a pc?
A processor controls the memory management and it also carries out computation on data by following instructions.
What does main memory do?
Main memory stores data and it instructions that will be used by the processor.
What is RAM
RAM (random access memory) is volatile memory that can be stored very quickly, this means that certain applications can run quickly. However when the power is turned off the ram looses all of its content.
What is ROM
ROM (read only memory) is a method of storing data and instructions. But it is mainly used for the start up if a computer.
What is addressable memory?
Addressable memory is made up of millions of addressable cells and various instructions that make up a program. This memory is organised via the address.
What are the three types of buses?
Data, Address, control
What does the data bus do?
Transfers data between the processer and memory. It also transfers data from the I/O controllers.
What is the address bus?
It is used to specify a physical address in memory so that the data bus can access it.
What is the control bus?
The control bus controls the flow of data between the processor and other parts of the computer.
What are I/O controllers
These are the direct link between the processor and the main memory. They send and receive instructions. Basic I/O devices are keyboard and mouse.
What is the Von Neumann architecture?
A technique for building a processor where data and instructions are stored in the same memory and accessed via the buses.
What is the Harvard architecture?
A technique for building a processor that uses separate buses and memory for data and instructions.
What is a HDD
A HDD is a hard disk drive. It is a secondary storage device made up of metallic disks that store data magnetically.
What is a controller in reference to a SSD?
A controller is in SSDs and is needed to organise data into blocks for storage purposes.
What are blocks in regard to storage?
A Block is the concept of storing data into sent groups of bits and bytes of a fixed length.
What is a Floating gate transistor?
It is in SSDs, it is a type of non-volatility transistor that stored data even without power.
How are magnetic hard disks constructed?
They are constructed of a hard metallic material and are hermetically sealed. They are made up in a number of disks arranged in a stack. The disks are coated with a thin film of magnetic material.
How is the data stored in a magnetic hard disk?
Changed in the direction of magnetism represents ones and zeros.
How is the data read from a MHD (Magnetic hard disk)?
There is an actuator arm which moves the head across the surface of the disk as it spins. Due to the combination of the rotating disks with the lateral movement of the arm means that the head can access every part of the disks surface.
How is the surface of the disks originised?
The surface of the disk is organised into concentrated tracks and each track is split into sectors each of which can be addressed individually by the OS. Because of the head assembly it can read any one of the disks, a cylinder reference is also used to identify which disk in the stack is being addressed.
What is an optical disk?
An optical disk is a generic term for all variations of CD, DVD, and Blu-Ray that use laser technology to write and read data.
How is an optical disk made up?
An optical disk is made up of one single spiral track that starts in the middle and works its way to the edge of the CD. The laser will read the data that is contained within this track by ready the pits and lands.
What are read-only optical disks?
A read-only optical disk is when the data is written. It is encoded as a series of bumps, pits and lands within the track layer on the disk.
How is data protected on a read-only optical disk?
After the data has been encoded onto the disk, a protective layer is put over the surface to prevent any corruption.
How are optical disks read?
The pattern of pits and lands are used to represent data, when the disk is ready the pits and lands are read by the laser which interprets each as different electrical signals (ones and zeros)
How are writeable disks writeable?
Rather then using pits and lands the disk is coated in a photosensitive dye, that is transparent. When writing the laser will alter the dye making it opaque. Which can then be interpreted as binary patterns.
What is a SSD?
A SSD is a is a memory device made up of semiconductors. It is also non-volatile meaning that the data is not lost when there is no power.
What is one benefit of a SSD over a HDD?
High speeds of data transfer can be achieved, compared with magnetic hard disks.
How are the semiconductors stored in a SSD?
They are stored in a unit that looks like a hard disk and they commonly use a type of memory called NAND memory. This organises the data into blocks like a traditional HDD.
How are the semiconductors able to retain data? In a SSD.
The semiconductors are able to retain data due to the type of transistor used.
What transistor is used to store the data in an SSD?
A SSD uses a floating gate transistor which is able to trap and store charge.
What is the basic concept of the Von Neumann architecture?
To store instructions and data in the same memory unit.
What is the basic instructions for fetch?
The processor fetched the programs next instruction from memory. The instruction sill be stored at a memory address and will contain the instruction in binary code.
What is the basic instruction for the decode part of the fde cycle?
The processor works out what the binary code at the address means?
What is the basic instructions for execute?
The processor carries out the instruction which may involve reading an item of data from memory performing a calculation or writing data back into memory.
What part of the processor supervises the FDE cycle?
The CU supervises the FDE cycle. It also makes sure that all the data that is being processed is pouted correctly.
What operations does the ALU carry out?
Arithmetic and logic. The ALU can be used to carry out normal mathematical operations as well as shifting. It can also be used to compare two values. Some comparisons can lead to true or false values being recorded.
How does the ALU process requests?
The ALU is sent an operation code and the operands. The ALU then uses logical or arithmetic operations to carry out the appropriate process.
What is the internal clock?
The internal clock is a clock that generates a signal that is used to synchronise the operations of the processor and the movement of data around the other components of the computer.
What is the speed of the clock measured in?
It is measured in gigahertz (GHz 1000 million cycles per second)
