Category Archives: Computer Organisation Theory

All important theory placed here!

Design and draw a 3 x 8 decoder using NOT gates and AND gates and explain its working. 8m Jun2007

Decoder converts one type of coded information to another form. A decoder has ‘n’ inputs and an enable line (a sort of selection line) and 2n output lines. Let us see diagram of 3×8 decoder which decodes a 3 bit information and there is only one output line which gets the value 1 or in… Read More »

Simplify Boolean function using Karnaugh map method F(A,B,C,D) = Σ(1,2,5,6,7,8,9,11,12,15) Also, draw the corresponding logic circuit diagram. 8m Jun2007

Simplify the following Boolean function using Karnaugh map method F( A ,B , C , D ) = Σ ( 1, 2 , 5 , 6 , 7 , 8 , 9 , 11 , 12 ,15 ) Also, draw the corresponding logic circuit diagram. 8m Jun2007   K-Map for F is: Thus, the simplified equations for F (A,… Read More »

Explain any five DOS function calls supported by INT 21H in the 8086 assembly language with an example of each call. 10m jun2006

(d) Explain, with an example of each call, any five DOS function calls supported by INT 21H in the 8086 assembly language.             10   DOS Function Calls (Using INT 21H) INT 21H supports about 100 different functions. A function is identified by putting the function number in the AH register. For example, if we… Read More »

Write a program to evaluate the following expression using an accumulator machine: A = B + C * D * E + F 7m jun2006

Write a program to evaluate the following expression using an accumulator machine: A = B + C * D * E + F     7m jun2006   Accumulator Architecture: An accumulator is a specially designated register that supplies one instruction operand and receives the result. The instructions in such machines are normally one-address instructions. The popular… Read More »

A program in 8086 assembly language that checks an input string against a password string stored in memory. 7m Jun2006

Write a program in 8086 assembly language that checks an input string against a password string stored in the memory and outputs an appropriate message if the strings are not equal.       7m Jun2006 DATA SEGMENT MSG1 DB 10,13,’ENTERED PASSWORD : $’ MSG2 DB 10,13,’YOU HAVE ENTERED WRONG PASSWORD !!! $’ MSG3 DB 10,13,’YOU HAVE ENTERED… Read More »

Explain the process of handling an interrupt that occurs during a program? 9m jun2006

Explain the process of handling an interrupt that occurs during the execution of a program, with the help of an example. 9m jun2006   Interrupt Handling and Instruction Cycle  On the occurrence of an interrupt, an interrupt request (in the form of a signal) is issued to the CPU. The CPU on receipt of interrupt… Read More »

What is the significance of FAT? What are the limitations of FAT 16? 4m jun2006

What is the significance of FAT? What are the limitations of FAT 16?  4m jun2006 FAT The FAT maps the usage of data space of the disk. It contains information about the space used by each individual file, the unused disk space and the space that is unusable due to defects in the disk. Since… Read More »

Explain any five addressing modes used in an 8086 microprocessor, with the help of an example of each. 5m jun2006

Explain any five addressing modes used in an 8086 microprocessor, with the help of an example of each.    5m jun2006 The following tree shows the common addressing modes: In general not all of the above modes are used for all applications. However, some of the common areas where compilers of high-level languages use them are:… Read More »

Write an 8086 assembly language program that finds the largest, and the second largest number from a list of 10 numbers stored in the memory 6m Jun2006

Write an 8086 assembly language program that finds the largest, and the second largest number from a list of 10 numbers stored in the memory 6m Jun2006 To understand program for Largest in an array in detail Please Click this link below http://cssimplified.com/computer-organisation-and-assembly-language-programming/an-assembly-program-for-finding-the-largest-number-in-array-of-10-elements DATA SEGMENT ARR DB 5,3,7,1,9,2,6,8,4 LEN DW $-ARR LARGE DB ? SECOND… Read More »