REVISION FOR TEST Flashcards
What makes up the processor?
Register, CU, ALU
What are the 2 tasks of components in a computer system?
Adding, storing
What are the functions of the processors
The fetch, decode, execute cycle
What is a register?
A temporary data store that holds the current instruction to be executed having been fetched from memory
What is the ALU?
The process and manipulation of data. Normally consists of arithmetic operations or logical comparisons that allows a program to make a decision
What is the CU?
Fetches each instructions in sequence, decode it and then synchronises it before executing it. Sends control signals to other parts of the computer
What is the Von Neumann Bottleneck?
Limitation between the CPU and RAM is lower than the speed the CPU can process data
What is the Von Neumann Architecture?
When the data and the software are stored in RAM. The task being carried out by the computer can be changed by loading a different piece of memory
When is the Bottleneck created?
When the instructions are fetched at the same time as data operations on the same memory and bus system
What is the first step of the Fetch-Decode-Execute cycle?
The PC displays the next address in RAM of the next instruction to be processed
This value is copied into the MAR
What is the second step of the Fetch-Decode-Execute cycle?
The PC Register increases by 1
This prepares the CPU for the next instruction to be fetched
What is the third step of the Fetch-Decode-Execute cycle?
The CPU checks the address in RAM which matches the address held in the MAR
What is the fourth step of the Fetch-Decode-Execute cycle?
The instruction in RAM is transferred to the MDR
What is the fifth step of the Fetch-Decode-Execute cycle?
The instruction in the MDR is copied into the CIR
What is the sixth step of the Fetch-Decode-Execute cycle?
The instruction in the CIR is decoded and executed
Any result of the execution is stored in the ACC
What are the 7 stages of the SDLC?
- Feasibility study
- Analysis
- Design
- Create
- Test
- Changeover
- Maintenance
What are the 2 approaches?
Agile, waterfall
What are the 4 main fact finding methods?
Observation, questionnaire, document collecting, interview
How do computers communicate with each other?
Using a protocol suite (TCP/IP protocol)
How many layers are in the protocol suite?
4
What do the layers do in the protocol suite?
Each layer depicts what task is carried out by which protocol
Each layer has more than 1 protocol
What is the application layer?
Allows the user to create messages that can be sent across the internet using a number of protocols
Any application will need the data to be formatted
What is the transport layer?
Controls the flow of data across the internet
Breaks messages down into packets
Checks the packets have arrived safely
What is the internet layer?
Delivers messages based on the address
Routes data between networks
Ensures relevant data is added to each packet (destination address, source address, packet number etc)
What is the network interface layer?
Physical connection that allows packets to be sent from one network interface to another
Determines how data is physically transmitted along a network
What protocols are in the Application Layer?
HTTP
FTP
POP
IMAP
SMTP
SNMP
What protocols are in the Transport Layer?
ICP
UDP
What protocols are in the Internet Layer?
IP
ICMP
What protocols are in the Network Interface Layer?
MAC
Ethernet
What is TCP (Transmission Control Protocol)?
Establishes connections between devices on a network, guarantees packets reach their destination
What is UDP (User Data Protocol)?
Sets up networks (like a TCP), doesn’t guarantee the arrival of a packet, faster than TCP
“Fire and Forget”
What is IP (Internet Protocol)?
Determines fields of information to be sent in packets (source address, destination address, packet number etc)
What is SMTP (Simple Mail Transfer Protocol)?
Mail server which stores sent mail until the user is online
What is POP3 (Post Office Protocol)?
Allows users to receive mail from the mail server
Downloads the mail from the server
What is FTP (File Transfer Protocol)?
Controls how files are sent over the network
What is HTTP (Hyper Text Transfer Protocol)?
Determines how the files that make up webpages are exchanged
What is SNMP (Simple Network Management Protocol)?
Allows certain administrative devices to see information about the devices connected to a network
What is ICMP (Internet Control Message Protocol)?
Handles transmission errors, alerts devices to any errors that have occurred and specifies the issue
What is a Network Standard?
Set of rules that allow different types of hardware to work together sending/receiving data
What would happen without network standards?
Different brands wouldn’t be compatible with each other. We wouldn’t be able to send/view different formats (sending a PDF to someone without a PDF reader)
What do protocols allow?
Allows different devices to communicate with each other (computer to printer)
