Blog: CS401 Finalterm paper 2013 File 16

27 Feb. 2013
CS 401:
Assalam o Alikm
80% MCQS From Handout and 20% from past papers:
Q.1: What are different registers settings for file closing using INT21 service?
Q.2: Which bit of port 37A enables the IRQ7 triggering by the ACK pin?
Q.3: How many types of users descriptors are uses in 8080 architecture? Write their names only.
Q.4: What is the purpose of direction flag (DF) and what will happen if DF= 1?
Q.5: In case of a typical central processing unit, how program counter governs the complete execution of an instruction?
Q.6: Following are three common video services for INT 10 used in text mode. Identify the use of each video service which is listed below:

• AH=00h
• AH=01h
• AH=02h

Q.7: How communication happens on serial port?
Q.8: In assembly language programming, which information is represented by descriptor’s first 16-bits?
Q.9: What are the contents at the starting position of the file designated as device driver and mention important attributes of this driver file?
Q.10: Which processor’s instruction set allows the following instructions and describe what task will be performed by each of these instructions:

• CLR(A3)
• EXG D0,D2
• Move.B (A1),(A2)
• MoveA (2222).L,A4

Q.11: Consider the following pseudo-code and write the assembly code for it. Note: There is more credit for a shorter code.
If(a1>b1) AND (b1>c1)
{
cx=1
}
Q.12: Explain the purpose of assembly language instructions from 1 to 4 lines as given below:
Mov si,I2
Mov al,[cs:si]
Mov [opcode],al
Mov byte [cs:si], 0xcc
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Kasoor Mera /b>