In the name of ALLAH, the most beneficient, the most merciful

Computer Architecture and Assembly Language Programming (CS401)

Multiple Choice Questions (MCQs)

Objective Questions

  1. The execution of the instruction "mov word [ES : 160], 0x1230" will print a character on the screen at:

    1. first column of second row
    2. second column of first row
    3. second column of second row
    4. first column of third row
  2. Which of the following gives the more logical view of the storage medium?

    1. BIOS
    2. DOS
    3. Both
    4. None
  3. In the instruction MOV AX, 5 the number of operands are _______.

    1. 1
    2. 2
    3. 3
    4. 4
  4. Sending the appropriate signals on the control bus to the memory is the responsibility of ________.

    1. Memory
    2. Processor
    3. Control Bus
    4. Data Bus
  5. ________ is set only when the last mathematical or logical operation produces a zero in its destination.

    1. Single Flag
    2. Zero flag
    3. Trap Flag
    4. Parity Flag
  6. The other directive is "define word" or "dw" with the same syntax as "db" but reserving a whole word of ________ bits instead of a byte.

    1. 32
    2. 8
    3. 16
    4. 64
  7. SP is associated with ____________ , by default.

    1. SS
    2. DS
    3. CS
    4. ES
  8. The purpose of MOVS instruction is:

    1. Move register to register
    2. Move register to a memory location
    3. Move a memory location to register
    4. Move memory to memory
  9. In multitasking, which of the following interrupts is used as scheduler during context switching?

    1. INT 21
    2. INT 16
    3. INT 13
    4. INT 8
  10. ______ is the highest priority interrupt in interrupt controller.

    1. IRQ 0
    2. IRQ 1
    3. IRQ 2
    4. IRQ 3
  11. This jump is taken if the last arithmethic operation produced a positive number in its destination.

    1. JNP
    2. JO
    3. JNS
    4. JG
  12. All the addressing modes return the number after calculation, this number is known as ________ ?

    1. Base Address
    2. Offset Address
    3. Data Address
    4. Effective Address
  13. Which part of this (00000000000 B80500) encoded instruction is an offset?

    1. First Column
    2. Second column
    3. B8
    4. 0500
  14. Physical memory adresses is of

    1. 16 Bits
    2. 32 Bits
    3. 20 Bits
    4. 8 Bits
  15. Which of the following Move generates error in .com file?

    1. Legal move
    2. Illegal move
    3. Ambiguous move
    4. Fetal move
  16. Stack is a data structure that behaves in a first in last ________ manner.

    1. In
    2. Out
    3. Push
    4. Add
  17. In DOS input buffer, number of characters actually read on return is stored in _______.

    1. 1st byte
    2. 2nd byte
    3. 3rd byte
    4. 4th byte
  18. MUL (multiply) instruction performs an unsigned multiplication of the source operand and the ________ .

    1. Accumulator
    2. Carry
    3. Word
    4. Base
  19. In ________ every bit moves one position to the right and the bit dropped from the right is inserted at the left and also copied into the carry flag?

    1. ROL
    2. RCR
    3. RCL
    4. ROR
  20. The extention of assembly languague file is

    1. .doc
    2. .com
    3. .lst
    4. .asm
  21. "INT 13-BIOS disk services" generally uses which register to return the 'error code'?

    1. CF
    2. DL
    3. AH
    4. AL
  22. An 8 x 16 font is stored in ______________ bytes.

    1. 2
    2. 4
    3. 8
    4. 16
  23. What does the given instruction do?
    SHR DL, 1

    1. move right most bit in carry
    2. move bit in DL
    3. Shift and store the One bit in DL
    4. Shift and store the most bit in DL
  24. The 'program segment prefix' for com files is of size:

    1. 64 bytes
    2. 128 bytes
    3. 256 bytes
    4. 512 bytes
  25. Number of operands of ADC (add with carry) register are:

    1. 1
    2. 2
    3. 3
    4. 4
  26. In STOSW instruction, when DF is clear, DI is ___________

    1. Incremented by 1
    2. Incremented by 2
    3. Decremented by 1
    4. Decremented by 2
  27. mov [1234], ax is an example of

    1. direct addressing
    2. base register indirect
    3. base+index addressing
    4. register indirect addressing
  28. The interrupt call loads new values in ________ segment.

    1. ES
    2. DS
    3. CS
    4. SS
  29. In DOS input buffer, the number of characters actually read on return is stored in ___________ byte.

    1. 3rd
    2. 4th
    3. 1st
    4. 2nd
  30. Which of the following is a non-destructive AND operation?

    1. AND
    2. XOR
    3. OR
    4. Test
  31. Which of the following interrupts is Non maskable interrupt?

    1. INT 2
    2. INT 3
    3. INT 0
    4. INT 1
  32. The jump command that does not depend on FLAG register is

    1. JCXZ
    2. JO
    3. JNE
    4. JP
  33. All mathematical and logical operations are performed on the ________.

    1. Accumulator
    2. Arithmetic Logic Unit
    3. Program Counter
    4. Flag Register
  34. The instruction, MOV AX, 0005H belongs to the address mode of ________ .

    1. Register
    2. Direct
    3. Immediate
    4. Register Relative
  35. Which of the following addressing scheme has been used in the instruction MOV [BX], AX?

    1. Base Register Direct
    2. Base Register Indirect
    3. Base + Offset
    4. Base + Index
  36. If AX=5, BX=5, CF and ZF are set, AF and DX contains zero then after the execution of instruction "ADC AX, BX", AX will contain the value ________.

    1. 5
    2. 10
    3. 11
    4. 6
  37. ________ is a special instruction that load a segment register and a general purpose register from a memory locations.

    1. SCAS
    2. MOV
    3. CALL
    4. LES
  38. In case of 32-bit processor, the size of an accumulator register will be ________ bits.

    1. 16
    2. 8
    3. 32
    4. 64
  39. BH register is a ________ bit register.

    1. 8
    2. 16
    3. 24
    4. 32
  40. The jump is taken if the last arithmetic operation changed the sign unexpectedly.

    1. JO
    2. JNO
    3. JNZ
    4. JZ
  41. How many characters were defined by standard ASCII?

    1. 132
    2. 124
    3. 122
    4. 128
  42. Which of the following register is used to hold address of the next instruction to be executed?

    1. Memory address register
    2. Memory data register
    3. Instruction registers
    4. Program counter
  43. There are just ________ block processing instructions in 8088.

    1. 6
    2. 5
    3. 4
    4. 3
  44. In general, width of a memory cell cannot be greater than the width of ________.

    1. Control Bus
    2. Data Bus
    3. Address Bus
    4. I/O Bus
  45. The 8088 processor divides interrupts into ________ classes.

    1. One
    2. Two
    3. Three
    4. Four
  46. Which of the following registers hold the page number for using the write string service of INT 10?

    1. AH
    2. BL
    3. CL
    4. BH
  47. In branching mechanism, the assembler

    1. Replaces the target with its address
    2. Does not replace until the test condition is satisfied
    3. Finds the Branch offset and replaces the Branch target with it
    4. Replaces the target with the value specified by the DATAWORD directive
  48. SCAS compares a source byte or word in register AL or AX with the ________ string element addressed by ES: DI and updates the flags.

    1. Source
    2. Destination
    3. Flag
    4. Register
  49. ASCII table is the contiguous arrangement of the upercase alphabets (41-5A), the lowercase alphabets (61-7A), and the numbers ________.

    1. 31-40
    2. 29-39
    3. 30-39
    4. 31-41
  50. Which of the following string instruction is generally used in a loop instead of REP prefix?

    1. SCAS
    2. LODS
    3. CMPS
    4. STOS
  51. "mov [bp], al" moves the one byte contents of the AL register to the address contained in BP register in the current ________.

    1. Stack Segment
    2. Data Segment
    3. Code Segment
    4. Extra Segment
  52. In a comparison, if the both operands are same. The result of subtraction will be zero and the zero flag will be ________.

    1. Set
    2. Incremented
    3. Updated
    4. Decremented
  53. MOV [BX+SI+300], AX is a ________ addressing mode instruction.

    1. Base + Index + Offset
    2. Base + Index
    3. Index Register Indirect + Offset
    4. Illegal
  54. We can set the current file position in DOS using service number ________.

    1. 0x38
    2. 0x40
    3. 0x42
    4. 0x43
  55. In the context of video services, if we want to set cursor position which of the following will be the value of AH?

    1. AH = 01h
    2. AH = 02h
    3. AH = 03h
    4. AH = 04h
  56. DX plays an important role in arithmetic ________.

    1. addition
    2. multiplication
    3. division
    4. subtraction
  57. Which of the following is used to terminate a string in assembly language?

    1. !
    2. #
    3. $
    4. ;
  58. Which of the following INT 21 service is used to read character from standard input?

    1. 00
    2. 01
    3. 02
    4. 03
  59. When an element is pushed on the stack SP is decremented by ________.

    1. 3
    2. 2
    3. 4
    4. 1
  60. Which of the following operation is used to clear any specific bit in a binary number?

    1. AND
    2. OR
    3. XOR
    4. NOT
  61. Group of bits processor uses to inform memory which element to read/write is collectively known as

    1. Control bus
    2. Data bus
    3. Address bus
    4. RAM
  62. ________ is the basic means of sorting temporary data on the stack.

    1. PUSH
    2. POP
    3. CALL
    4. RET
  63. Which bit of the attributes byte represents the red component of foreground color?

    1. 5
    2. 4
    3. 3
    4. 2
  64. There are ________ registers in iAPX88 architecture that can hold address of data.

    1. 1
    2. 2
    3. 3
    4. 4
  65. ________ is a temporary storage places inside the processor.

    1. Memory
    2. Ram
    3. Cache
    4. Register
  66. Which of the following services of INT 10 is used for writing the string?

    1. 0x12
    2. 0x13
    3. 0x11
    4. 0x10
  67. ________ and ________ are taken if the last arithmetic operation produced a number in its destination that has odd parity.

    1. JP, JPE
    2. JS, JNS
    3. JCX, JNS
    4. JNP, JPO
  68. When a 32 bit number is divided by a 16 bit number, the quotient is of _______.

    1. 32 bits
    2. 16 bits
    3. 8 bits
    4. 4 bits
  69. The top of stack is contained in ________ register.

    1. SP
    2. BP
    3. AX
    4. BX
  70. CX register is mostly used as a

    1. counter register
    2. flag register
    3. base register
    4. destination register
  71. ________ instruction makes the code reusable.

    1. Mov
    2. JMP
    3. CALL
    4. SHL