Chapter 8

Question 1

Can register be subtracted

Answer 1

No

Question 2

Can 2 base registers be added

Answer 2

No

Question 3

Can 2 indices be added

Answer 3

No

Question 4

What is formula of effective address

Answer 4

EA = base + index + offset

Question 5

What is the formula of physical address

Answer 5

Physical address = segment * 0x10 + EA

Question 6

What is segment wrap around

Answer 6

Removing extra bit

Question 7

What is memory wrap around

Answer 7

Removing extra bit

Question 8

What is jz

Answer 8

jump is zero

Question 9

What is je

Answer 9

jump if equal

Question 10

What is jne

Answer 10

jump if not equal

Question 11

What is jc

Answer 11

jump if carry

Question 12

What is jnc

Answer 12

jump if not carry

Question 13

What is ja

Answer 13

Jump if above

Question 14

What is jb

Answer 14

Jump if below

Question 15

What is jl

Answer 15

jump if less

Question 16

What is jg

Answer 16

jump if greater

Question 17

What is jae

Answer 17

jump if above or equal

Question 18

What is jbe

Answer 18

jump if below or equal

Question 19

What is jge

Answer 19

jump if greater or equal

Question 20

What is jle

Answer 20

jump if less or equal

Question 21

What is jno

Answer 21

jump if not overflow

Question 22

What is jns

Answer 22

jump if not sign

Question 23

What is jcxz

Answer 23

jump if cx register is zero [cx=0]. It is special jump and not dependent on flag.

Question 24

What is CMP

Answer 24

The basic root instruction for all comparisons is CMP standing for compare.

Question 25

What is operation of CMP

Answer 25

The operation of CMP is to subtract the source operand from the destination operand, updating the flags without changing either the source or the destination.

Question 26

What is the role of cary flag

Answer 26

The carry flag plays the role of borrow during the subtraction operation. It carry the overflow.

Question 27

What is the difference between signed and unsigned numbers

Answer 27

In unsigned numbers only the magnitude of the number is important, whereas in signed numbers both the magnitude and the sign are important.

Question 28

16th bit holds what

Answer 28

It holds data, not the sign.