Unit 1 - OCR computer science

what is the CPU?

Central Processing Unit; the brain of the computer.

what is a practical example of 3d face recognition?

security cameras.

what is the CU?

control unit - sends signals to control how data moves around the CPU

where are 3D scanners used?

both industrial and medical fields.

what is a bus?

It is a part of the computer that transfers data, addresses, and signals between the components of the computer.

what is a sensor?

An input device that takes readings from the environment such as temperate or light.

what is the system bus?

The collection of the data bus, address bus, and control bus is called the system bus.

what are analogue measurements?

Gas, infrared, light, temperature, pressure, pH level, magnetic field, moisture.

what is memory read?

Causes data from the addressed location to be placed on the data bus.

what is monitoring?

microprocessor will only report the values it is reading.

what is memory write?

Causes data on the data bus to be written into the addressed location.

what is control?

the microprocessor can make an input based on a value.

what is the bus request?

shows that a device is requesting the use of the data bus

what is an example of a detection system?

pressure sensors, infrared sensors.

what is the bus grant?

Indicates that the CPU has granted access to the data bus.

what are output devices?

Output devices are used to send data from a digital device to a user or another device.

what is the clock?

It produces a signal that synchronises and helps move data around parts of the computer system. It is measured in hertz / number of cycles that the CPU can complete in one second.

what is an inkjet printer?

Inkjet printers produce high quality prints.

Inkjet printers are easy to use and inexpensive compared to laser printers.

However, the nozzles are prone to clogging and the ink is wet after printing.

A feeding mechanism draws paper in and the paper passes by the print head where ink is sprayed onto it.

what is the ALU?

Arithmetic logic unit. Part of the CPU that carries out two types of operations: the arithmetic and the logic operations

what is a laser printer?

Use laser beams to write information on photosensitive drums; produce high resolution text and graphics

what is the ACC?

Accumulator - Used to store the results of arithmetic operations.

what is a dot matrix printer?

they can print to multipart forms. They have a printhead that holds the pins or printwires that strike the inked ribbon.

what is the PC?

Program Counter - Holds the address of the next instruction to be executed

what are 3D printers?

a device that manufactures a 3 dimensional objects by building the object up one layer at a time

what is the MDR?

Memory Data Register - Holds the actual data or instruction

what are some uses for a 3D printer?

medical - prosthetic limbs or orthotics. manufacturing - cars or prototypes.

what is the MAR?

Memory address register - holds any memory address about to be used by the CPU

What is RFID used for?

RFID is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags.

An RFID tag is an object that can be attached to or incorporated into a product, animal, or person for the purpose of identification using radio waves.

what is the CIR?

holds the current instruction, which it splits up into operand and opcode.

what is a LCD?

Liquid Crystal Display

what is operand?

The operand is the address of where the operation is performed.

what are the two types of memory?

RAM and ROM

what is opcode?

Opcode is used to determine the type of instruction and what hardware to use to execute it.

what is RAM?

Random Access Memory. Internal memory in the computer used during immediate processing.

what are words?

•Memory is divided up in equal units called words. Word length is usually 8, 16, 32 or 64 bits. Each word has a separate memory address

what is ROM?

Read Only Memory

- When the computer is loaded up, it looks in the BIOS chip in the ROM for the start up instructions (e.g. load up OS from the HDD)

what is machine code?

binary data

what is the difference between primary and secondary storage?

Primary memory is volatile and secondary memory is non-volatile

what is assembly language?

low level language that allows machine code to be read.

what is a hard disk?

It is a large-capacity permanent storage that is used to hold information such as programs and documents.

for each word, there is a..?

seperate memory address.

what is a SSD?

Solid State Drive

The width of the address bus determines the...?

maximum possible memory addresses in the system.

what is the difference between HDD and SSD?

HDD is mechanical and has moving parts (moving "platters" and reader arm - much like a record). SSD is made of transistors and has no moving parts.

the data bus has the same width as...?

a single computer word.

operand's max size will depend on...?

the width of the address bus.

what is clock speed?

It is how many cycles can be completed per second (Hertz)

what is the system clock?

A series of regular ON/OFF signals used to synchronise the operations of the processor components.

what is the rising edge?

A signal changing from a low state to a high state. (0 to 1)

each core theoretically is able to process a different instruction at the same time with its own fetch-execute cycle. True or False?

True.

what is parallel processing?

Using several processor cores working at the same time.

what is cache memory?

A special, super-fast part of the RAM that can be accessed more quickly than regular RAM.

- The CPU first looks in the cache and if it finds what it wants there, it doesn't have to take the time to look in the RAM, Very expensive, Very close to CPU (level 1 is closest, and level 2 is a bit further)

what is the hierarchy of cache size?

1) Level 1 2) Level 2

What is pipelining?

The process of completing the fetch, decode and execute of three separate files simultaneously.

what is the stored program concept?

- A program must be loaded into main memory to be executed by the processor

- The instructions are fetched one at a time, decoded and executed sequentially by the processor

- The sequence of instructions can only be changed by a conditional or unconditional jump instruction

what is the von neumann architecture?

A system where the CPU runs programs stored in memory

what is the harvard architecture?

Architecture in which there is two separate memory and data buses for data and instructions.

which architecture do modern CPU chips use?

they use a mix of both von neumann and harvard architectures.

What is CISC?

Complex Instruction Set Computer - A large instruction set is used to accomplish tasks in as few lines of assembly language as possible

what is an example of CISC?

Mult A, B

what is RISC?

Reduced Instruction Set Computer - a minimum number of very simple instructions.

what is a multi-core processor?

a single chip with two or more separate processor cores

what are parallel systems?

Systems where multiple instructions can be completed at any given time, doesn't require multiple cores, it can use threading and pipelining instead.

software has to be written to take advantage of multiple cores. True or False?

True.

what is a co-processor system?

an extra processor used to supplement the functions of the primary processor (the CPU).

what is the GPU?

The Graphics Processing Unit is responsible for handling graphically intensive applications such as Adobe Creative Suite or Video Games.

A GPU has one core. True or False.

false.

what are some input devices?

mouse, keyboard, microphone.

what is an example of a pointing device?

mouse, trackerball.

what is an example of touchscreen technology?

Tablets, watches, mobile phones.

what are the two types of barcode readers?

universal product code version 'A', code 128

what are some uses of QR codes?

Restaurant coupons, mobile concert tickets, tourist info, advertising posters.