Which of the following Interrupt Requests (IRQ) is derived by the timer device?

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

DOS has a single entry point to access all of its services through ______________.

• A) INT 10
• B) INT 16
• C) INT 2
• D) INT 21

______________ is used in debugging along with the trap flag.

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

Which of the following instruction is used to return from an interrupt service routine?

• A) reti
• B) iret
• C) ret
• D) INTR

The output of Programmable Interval Timer (PIT) is connected to the _____________ line of Programmable Interrupt Controller (PIC).

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

Which of the following statements is correct regarding the input frequency of Programmable Interval Timer (PIT)?

• A) It depends on processor clock
• B) It is fixed
• C) It depends on hardware attached
• D) It is variable

In Programmable Interrupt Controller (PIC), which of the following ports is used to selectively enable or disable interrupts?

• A) 20
• B) 21
• C) 22
• D) 19

Which of the following is the ACK pin in DB-25 connector?

• A) 12
• B) 11
• C) 13
• D) 10

Which of the following instructions is used to disable all interrupts during the execution of a program?

• A) sti
• B) reti
• C) cld
• D) cli

Software interrupts are called by extended ____________ call mechanism.

• A) near
• B) short
• C) jmp
• D) far

Which of the following pins of DB-25 connector are ground?

• A) 25-32
• B) 10-17
• C) 18-25
• D) 2-9

The interrupt call loads new values in CS, IP and ______________.

• A) FLAGS
• B) DS
• C) BP
• D) SS

There are ___________ forms of MOVS instruction.

• A) three
• B) two
• C) five
• D) four

Which of the following is the number of pin(s) outside the processor for generating interrupts by the external hardware?

• A) 2
• B) 4
• C) 1
• D) 3

The IDTR is a ____________ bit register similar in structure to the GDTR.

• A) 48
• B) 128
• C) 64
• D) 32

Which of the following instructions, selects the memory address space?

• A) IN
• B) MOV
• C) ADD
• D) DEC

Which of the following flags is cleared with the help of stack?

• A) Interrupt flag
• B) Zero Flag
• C) Trap flag
• D) Direction flag

There are ____ forms of MOVS instruction.

• A) Three
• B) Four
• C) One
• D) Two

Interrupts are ________________ and ________________.

• A) asynchronous, predictable
• B) synchronous, predictable
• C) asynchronous, unpredictable
• D) synchronous, unpredictable

Which of the following is the source register in OUT instruction?

• A) AL or AX
• B) BL or BX
• C) CL or CX
• D) DL or DX