Notes in Assembly Language

Question 1

How many columns does a typical video screen have

Answer 1

80

Question 2

How many rows does a typical video screen have?

Answer 2

25

Question 3

Code for clearing screen

Answer 3

MOV AX,3
INT 10H

Question 4

MOV AH,0 (0000)

Answer 4

Video Mode

Question 5

MOV AH,1 ;(0100)

Answer 5

Single Character Input

Question 6

MOV AH,2 ;(0200)

Answer 6

Single Character Output

Question 7

MOV AH,6 ;(0600)

Answer 7

Monitor Screen Processing

Question 8

MOV AH,8 ;(0800)

Answer 8

Single Character Input No Echo

Question 9

MOV AH,9 ;(0900)

Answer 9

String Output

Question 10

MOV AH,10 ;(0A00)

Answer 10

String Input

Question 11

How many colors can background display?

Answer 11

8

Question 12

How many colors can be used as text color?

Answer 12

16

Question 13

What does the msb of the background color represent?

Answer 13

Blinking

Question 14

What does the msb of the text color represent?

Answer 14

Intensity

Question 15

Is used to compare character data, as well as, numeric data fields

Answer 15

CMP

Question 16

The main use is in decision making in conjunction with conditional jump instructions

Answer 16

CMP

Question 17

These are instructions that transfer control depending on the setting of CMP instruction whether a certain condition is met or not.

Answer 17

Conditional Jump

Question 18

Is considered an unconditional jump instruction because the machine always executes it

Answer 18

JMP

Question 19

Make it possible to break a large program down into smaller pieces so that each piece can be shown to work correctly without reference to any of the others

Answer 19

Procedure

Question 20

Used for filling in time or filling space on tape when there is no data

Answer 20

NUL (null)

Question 21

Used when there is need to call human attention

Answer 21

BEL (bell)

Question 22

Indicates that the code combinations, which follow, shall be interpreted as outside of the standard character set until SHIFT IN character is reached

Answer 22

SO (Shift Out)

Question 23

Used to obliterate unwanted characters

Answer 23

DEL (delete)

Question 24

A nonprinting used to separate words, or to move the printing mechanism or display cursor forward by one position

Answer 24

SP (space)

Question 25

A character which shall change the meaning of one or more contiguously following characters.

Answer 25

DLE (Data Link Escape)

Question 26

It can provide supplementary controls, or permits the sending of data characters having any bit combination

Answer 26

DLE (Data Link Escape)

Question 27

Character for the control of auxiliary devices or special terminal features

Answer 27

Device Controls

Question 28

Indicates that the data which precedes it in message or black, should be disregarded

Answer 28

CAN (cancel)

Question 29

Indicates the physical end card, tape or other medium, or the end of the required or used portion of the medium

Answer 29

EM (End of Medium)

Question 30

Substitute for a character that is found to be erroneous or invalid

Answer 30

SUB (Substitute)

Question 31

A character intended to provide code extension in that it gives a specified number of continuously following characters an alternate

Answer 31

ESC (Escape)

Question 32

Indicates movement of the printing mechanism or display cursor backwards one position

Answer 32

BS (Backspace)

Question 33

Indicates movement of the printing mechanism or display cursor to the next pre assigned "tab" or stopping position

Answer 33

HT (Horizontal Tab)

Question 34

Indicates movement of the printing mechanism or display cursor to the start of the next line

Answer 34

LF (Line Feed)

Question 35

Indicates movement of the printing mechanism or display cursor to the next series of pre-assigned printing lines

Answer 35

VT (Vertical Tab)

Question 36

Indicates movement of the printing mechanism or display cursor to the starting position of the next page, form or screen

Answer 36

FF (Form Feed)

Question 37

Indicates movement of the printing mechanism or display cursor to the starting position of the same line

Answer 37

CR (Carriage Return)

Question 38

Used to indicate the start of a heading, which may contain address or routing information

Answer 38

SOH (Start of Heading)

Question 39

Used to indicate the start of the text and also indicates the end of the heading

Answer 39

STX (Start of Text)

Question 40

Used to terminate the text, which was started was started with STX

Answer 40

ETX (End of Text)

Question 41

Indicates the end of a transmission, which included one or more "text's" with their headings

Answer 41

EOT (End of Transmission)

Question 42

A request for a response from a remote station

Answer 42

ENQ (Enquiry)

Question 43

A character transmitted by a receiving device as an affirmation response to sender

Answer 43

ACK (Acknowledgement)

Question 44

A character transmitted by a receiving device as a negative response to polling messages

Answer 44

NAK (Negative Acknowledgement)