When ret function is called SP is ______ by _____

• A) Decremented, 2
• B) Incremented, 1
• C) Incremented, 2
• D) Deceremented 1

What is the purpose of ports 20 and 21 in the Programmable Interrupt Controller (PIC)?

• A) Port 20 is for keyboard input, and port 21 is for mouse input.
• B) Port 20 is the interrupt mask register, and port 21 is the control port.
• C) Port 20 is for sound card communication, and port 21 is for network card communication.
• D) Port 20 and port 21 both serve as control ports for the PIC.

Stack behaves as

• A) First in Last out
• B) First in First Out
• C) Last In First Out
• D) Last in Last out

IRET returns on the basis of ________ and __________.

• A) CS, SS
• B) CS, IP
• C) DS, IP
• D) IP, SP

SP register points to_______.

• A) Bottom of stack
• B) Top of stack
• C) Highest limit of stack
• D) Current item of stack

The_______ bit tells that this is a system descriptor while the 1110 following it tells that it is a 386 interrupt gate.

• A) O
• B) S
• C) T
• D) P

Each entry of the interrupt vector table is of __________ bytes.

• A) 2
• B) 1
• C) 3
• D) 4

__________ interrupt is used for Arithmetic overflow.

• A) INT 4
• B) INT 7
• C) INT 8
• D) INT 6

Whenever ret function is called

• A) nothing happens in stack
• B) Stack is pulled
• C) Stack is cleared
• D) Stack is pushed

If a _____ stack starts at location 8, the first item pushed on it will be placed at location 8, the second element will be placed at location 7 and so on.

• A) Decrementing
• B) Incrementing
• C)
• D)

In interrupt masking, We use ________ to get control from the program without letting the program know about it.

• A) IRQ 0
• B) IRQ 1
• C) IRQ 2
• D) IRQ 3

Whenever an element is pushed on the Stack, _____ register is decremented by 2.

• A) BP
• B) CS
• C) IP
• D) SP

Which register will be on the top of the stack after execution of the following assembly code? push ax push cx push bx pull ax pull dx

• A) BX
• B) AX
• C) DX
• D) CX

How many possible I/O ports are there in the Intel architecture when using the lower 16 bits of the address bus?

• A) 256
• B) 65536
• C) 1024
• D) 512

____________ is the highest priority interrupt in interrupt controller.

• A) IRQ 2
• B) IRQ 1
• C) IRQ 3
• D) IRQ 0

Changing and restoring the state of Central Processing Unit (CPU) is referred as:

• A) Multitasking
• B) Multithreading
• C) Context Switching
• D) Thrashing

What effect does setting bit 7 in the attribute byte have on the foreground character (in the context of display memory)?

• A) Changes background color
• B) Intensity of foreground color
• C) Clears the screen
• D) Initiates blinking

How is the screen location calculated (in the context of display memory formation)?

• A) Using the MUL instruction
• B) Dividing row and column numbers
• C) Multiplying row number by 80 and adding column number
• D) Adding row and column numbers

What does the attribute byte in the word designated for one screen location hold?

• A) Cursor height information
• B) Foreground and background colors
• C) Video controller instructions
• D) ASCII code for the character

How many I/O Ports are there?

• A) 65536
• B) 65548
• C) 65520
• D) 65524