Chapter 4

Question 1

how to run file in debugger

Answer 1

afd ex01.com

Question 2

how to run assembly file

Answer 2

nasm ex01.asm -o ex01.com -l ex01.lst

Question 3

how to edit lst file

Answer 3

edit ex01.lst

Question 4

how to capture any particular register

Answer 4

m1 ds:0100

(note: here ds is d register
0100: its value)

Question 5

what is the size of db

Answer 5

1 byte 
(db = define byte)

Question 6

What is the size of dw

Answer 6

2 byte
(define word)

Question 7

What is the size of dn

Answer 7

4 bit
(dn = define nibble)

Question 8

What is linear memory model

Answer 8

In linear memory model the whole memory appears like a single array of data.

Question 9

What is segmented memory model

Answer 9

The segmented memory model allows multiple functional windows into the main memory, a code window, a data window etc.

Question 10

What is Paragraph Boundaries

Answer 10

As the segment value is a 16bit number and four zero bits are appended to the right to make it a 20bit number, segments can only be defined a 16byte boundaries called paragraph boundaries.

Question 11

What is Overlapping Segments

Answer 11

We can also observe that in the case of our program CS, DS, SS, and ES all had the same value in them. This is called overlapping segments so that we can see the same memory from any window. This is the structure of a COM file.

Question 12

What is logical address

Answer 12

The segment, offset pair is called a logical address. Logical addressing is a mechanism to access the physical memory

Question 13

What is physical address

Answer 13

the 20bit address is a physical address which is the real thing