Ааааааа Flashcards
ALU
Part of the processor that process and manipulates data
CPU
Brain of a computer
CU
Part of the computer that manages the execution of instructions
Registers
The section of high speed memory within the CPU that stores data to be processed
Buses
Move data around the computer
Address Bus
Carries signals between the processor and the memory
Unidirectional
Data Bus
Sends data between the processor, the memory unit and the I/O devices
Bidirectional
Control Bus
Carries signals relating to the control and coordination of activities within the computer
I/O controller
Controls the flow of information between the processor and the input and output devices
System Bus
The main highway connecting the processor, main memory and I/O controllers
The Fetch Decode Execute cycle
Process by which a computer
Fetches a program instruction from it’s memory
Determines what the instruction wants to do
Carries out those actions
Program counter
An incrementing counter that keeps track of the memory address of which instructions is to be executed next
Memory address register
The address in main memory that is currently being read or written
Memory Buffer Register
A two way register that holds data fetched from memory or data waiting to be stored in memory
Current Instruction Register
A temporary holding ground for the instruction that has just been fetched from memory
System software
Performs the task needed to operate software
Software
Consist of sequences of instructions called programs that can be understood and executed by hardware
Library
Collections of compiled routines that other programs can use
Utility
Programs that perform a very specific task related to working with computers
Translator
Translate source code and assembly code to machine code
Operating system
Software that communicates with the hardware and allows other programs to run
Application software
Software designed to help the user to perform specific task
General purpose software
Software that can be used for many different tasks
Specific purpose software
Software designed to support one specific task
Bespoke Software
Written for a customer’s specific need
Multi programming
A number of jobs queued in memory to be processed
Time slice
Each job in memory is given a small amount of processing time every second
Scheduler
Part of the OS that decides time or order
Latency
Time required to perform some action or to produce some result
Logic circuit
Several logic gates combined together
SDLC steps
Analysis, Design, Implementation, Testing, Maintenance
Agile model
+ functionality can be developed fast
Resource requirement are minimum
Suitable for fixed or changing requirements
- not suitable for handling complex dependencies
Very high individual dependency
Depend heavily on customer interaction
Spiral model
+ Changing requirement can be accommodated
Allows for extensive use of prototypes
Requirements can be captured more accurately
- management is more complex
End of project may not be known early
Not suitable for small projects
Waterfall model
\+ simple and easy to understand and use Phases are processed and completed an at a time works well for smaller projects - high amount of risk Not suitable for complex projects It is difficult to measure progress
Throuput
Number of such actions executed or results produced per unit of time
