Fundamentals of Computer Systems Flashcards
What is Hardware?
The physical components of a computer system.
e.g. keyboard, mouse, mic
What is Software?
The code or programs that run on the hardware.
e.g. word processor, Microsoft edge, photoshop, Visual Studio
What is System Software (+ what are its 4 main types)?
System software aids in system running. any software that assists with the running or management of the computer system.
• OS
•.Utility
• Library
• Translators: Assembler, Compiler, Interpreter
What is an Operating System?
Allows the user to control the computer with ease.
It provides a virtual machine, hiding the true complexity of the computer from the user.
As a result, we can use other computers with the knowledge from another due to the OS.
e.g Windows, Ios, Linux.
Handles: memory management, processor scheduling etc.
What are Utility programs?
Used to complete housekeeping tasks in the computer system.
e.g. data backup, defragmenting hard drives (reorganising data on a hard drive to improve speed of access), data compression and encryption, antivirus etc.
What are Library Programs?
Libraries contain useful functions that are frequently used by a program.
Programmers make use of libraries when developing a program to simplify the process.
Must he imported within their program.
Speedily make a program.
e.g. Netframework, Netcore, OpenSSL
What are Translators?
Pieces of software which translate between different types of programming languages.
Microsoft Visual Studio (Compiler)
Python (Interpreter)
Fortran Assembly Program (FAP)
The Fetch & Execute Cycle
Program Counter
Memory Address Register
Address Bus
Main Memory
Data Bus
Memory Data Register
Current Instruction Register
PC + 1
Decode
Opcode
Operand
Execute
What does the PC (program counter) do?
holds address of the next instruction
What does the MAR do?
holds the address you’re accessing in memory.
What does the address bus do?
Transports memory addresses, specifying where data is to be sent to or retrieved from.
What does Main Memory do?
Memory that can be directly accessed by the processor.
Allows system to run instructions.
e.g. RAM, ROM
What does the Data Bus do?
Sends data and instructions to and from the different components of the computer system.
What does the MDR do?
Holds the contents of a memory location that has been read from, or data that is to be stored
What does the CIR do?
holds current instruction.
What does PC + 1 do?
The program counter is incremented by 1 to access the address of the next instruction that needs to be executed.
Next instruction to be executed typically kept in the following memory location.
What happens in the DECODE stage?
The control unit decodes the instruction in the CIR into OPCODE and OPERAND.
What is Opcode?
code needed to perform the instruction.
What is Operand?
Pieces of data that come with the instruction.
What is meant by a register?
A small, fast memory location in the CPU.
What is meant by addressable memory?
each memory location has an address.
What is the STORED PROGRAM CONCEPT?
Machine code instructions stored in main memory are fetched and executed serially by a processor that performs arithmetic and logical operations.
What does the control bus do?
carries control signals that regulate the operation of the computer system.
e.g. clock, interrupt, reset, stats, I/O write, I/O read, memory read, memory write, transfer request
What is Von Neuman Architecture?
• data and instructions stored in main memory.
• instructions sent to processor along system bus.
• data sent to and from processor is sent along system bus.
• all input/output transported by system bus.
• fear of bottlenecking, cannot do simultaneously.
What is Harvard Architecture?
Separate buses used for data and instruction, both of which address different parts of memory.
Used for embedded systems such as cars, washing machines etc.
What is Direct Addressing?
A form of addressing an instruction such that the operand is the address of the required datum (singular of data)
What is Immediate Addressing?
A form of addressing an instruction such that the operand is the require datum (singular of data)
