CS401 MIDTERM FALL2010

One screen location corresponds to a

Byte

Word

Double byte

Double word



After the execution of “PUSH AX” statement

AX register will reside on the stack

A copy of AX will go on the stack

The value of AX disappear after moving on stack

Stack will send an acceptance message

physical address of the stack is obtained by
SS:SP combination
SS:SI combination

SS:SP combination

ES:BP combination

ES:SP combination
If the address of memory location Num1 is 0117 and its content is 0005 then after execution of the instruction “ mov bx, Num1” bx will contain
0005
0117
Num1
1701

In STOS instruction, the implied source will always be in

AL or AX registers

DL or DX registers

BL or BX registers

CL or CX registers
The shift logical right operation inserts

A zero at right

A zero at left

A one at right

A one at right

REP will always
Increment CX by 1
Increment CX by 2
Decrement CX by 1
Decrement CX by 2

When an item is pushed on the decrementing stack, the top of the stack is

First decremented and then element copied on to the stack

First incremented and then element copied on to the stack

Decremented after the element copied on to the stack

Incremented after the element copied on to the stack

assembly the CX register is used normally as a ______________register.
source
counter
index
pointer
Which is the unidirectional bus ?
(I) Control Bus
(II) Data Bus
(III) Address Bus
I only
II only
III only
I and II only

The basic function of SCAS instruction is to
Compare
Scan
Sort
Move data


_______ register holds the address of next instruction is to be executed
Base pointer
Code segment
Source index
Program counter




JC and JNC test the ____________ flag.
carry
parity
zero
sign

After the execution of REP instruction CX will be decremented then which of the following flags will be affected?

CF
OF
DF
No flags will be affected

In string manipulation whenever an instruction needs a memory source, which of the following will hold the pointer to it?

ES: DI

ES: BP

DS:BP

DS:SI


which bit sets the character "blinking" on the screen?

5
6
7
8

If we want to divide a signed number by 2, this operation can better be accomplished by
SHR
SAR
SHL
SAL

After the execution of STOSWB,the CX wil be……..
Incremented by 1
Incremented by 2
Decremented by 1
Decremented by 2


Each screen location corresponds to a word, the lower byte of this word contains ____

The character code
The attribute byte
The parameters
The dimensions


In a video memory, each screen location corresponds to
One byte
Two bytes
Four bytes
Eight bytes
Q.
Number2:
IF DF=0 what its represent and IF DF=1 what its represent ?



Q.
Relation between RET and CALL is dependent or independent.

Q.

Write all steps of algorithm for printing number 352.


Q.

When the instruction "push ax" is executed in decrementing stack how the value of SP will change






Q.

What is wrong with this program?











Q.

Explain MUL instruction in both cases (i) if the source operand is byte (ii) if the source operand is a word?


Sponsored Links