Brain of the computer
What does the ALU stand for, and what does it do?
Arithmetic Logic Unit – performs arithmetic (+, –) and logical operations (AND, OR, NOT).
Is RAM volatile or non-volatile?
Volatile – it loses contents when power is turned off.
State the three (or four) stages of the machine instruction cycle.
Fetch, decode, execute. (sometimes, store as well)
Name one function of an operating system.
Provide user interface, manage memory, manage peripherals, multitasking, security.
Give one example of secondary storage.
Hard disk, SSD, USB flash drive, optical disk.
Which register holds the address of the next instruction?
The Program Counter (PC).
What does ROM typically store?
The BIOS or firmware needed to boot the computer.
What is the difference between system software and application software?
System software (OS, utilities) runs the computer; application software helps the user perform tasks.
Name the buses that link the MAR and MDR with RAM.
MAR = Address Bus
MDR = Data Bus
Which part of the CPU directs the data flow between the ALU, registers, and memory during execution?
The Control Unit (CU).
Microsoft Word and Excel are types of which two application softwares?
Word processor and Spreadsheet.
What are common features shared by most application software?
Toolbars, menus, icons, dialogue boxes, GUI components, save/open options.
fill in the blank: The _______ holds the intermediate results of the currently running instructions.
Accumulator.
Explain why cache is faster than RAM.
Cache is built inside/very close to the CPU and uses faster circuitry, so access time is shorter.
What happens in the execute stage if the instruction involves arithmetic, and where is it then stored?
The ALU carries out the calculation and stores the result in the accumulator or register.
Give one example of how the OS provides security.
Through login systems, passwords, and file permissions that prevent unauthorized access.
Explain the relationship between the MAR and MDR.
MAR = address of the memory location.
MDR = data at/from that location.
When RAM reaches its full capacity, what does the computer do to keep programs running, and what is one drawback of this process?
The operating system uses virtual memory, temporarily storing data on secondary storage (HDD/SSD) as if it were RAM. This allows programs to continue running, but it is much slower than using real RAM, which can reduce performance.
Walk through the fetch–decode–execute cycle step by step, naming the registers and buses involved.
PC → MAR (address placed on address bus) → RAM → MDR (data via data bus) → IR (instruction stored) → CU decodes → ALU/CU executes → result stored in register or memory.
What is the role of device drivers in peripheral management?
They act as translators between hardware devices and the OS, allowing communication.