Dev

Wednesday, 8 April 2015

How to make your pc faster than before?

Making PC faster
To make you PC faster than before flow the the following steps:


Step 1:Go to start then click run and then type regedit

Step 2: Select HKEY_CURRENT_USER and then select control panel folder

Step 3: Then select desktop folder

Step 4: You will see registry setting at your right hand side after that select menu show delay and                     then right click and select modify.

Step 5:You will see edit string option -----> default value data is 400
            you have to change it to 000

Step 6: Restart your computer. You will see your computer is much more faster than before.


Friday, 3 April 2015

Designing One Pass Assembler

One Pass Assembler
Introduction:
Assembler is a software program that converts the assembly language to machine language. Machine languages consist entirely of numbers and are almost impossible for humans to read and write. Assembly languages have the same structure and set of commands as machine languages, but they enable a programmer to use names instead of numbers. Each type of CPU has its own machine language and assembly language, so an assembly language program written for one type of CPU won't run on another. Programmers use assembly language when speed is essential or when they need to perform an operation that isn't possible in a high-level language. Assembler is the step comes in between a source code and .exe file. The assembler creates object codes.
A two-pass assembler reads through the source code twice. Each read-through is called a pass. On pass one the assembler doesn't write any code. It builds up a table of symbolic names against values or addresses. On pass two, the assembler generates the output code, using the table to resolve symbolic names, enabling it to enter the correct values. The advantage of a two-pass assembler is that it allows forward referencing in the source code because when the assembler is generating code it has already found all references.
Fig: Different files created by assembler


Project description:
This is the design of assembler project as a mini project under the term paper topic of the system software. In this project I will demonstrate how the assembler will produce and interact with the various databases to convert the assembly language source program to machine instruction that can be understood by the particular machine after linking the object code using linker.
          In this project I am going to develop the following databases to convert source code in assembly language to object code
·         Symbol table
·         Literal table
·         Base table
Technology to be used:
To convert the source code in assembly language into the machine code c language is used.
Limitation:
As a initial programmer in the field of designing the assembler, in this project I have taken one static example to show how assembler generate the various databases and interact through those database in first pass and second pass to convert the source code into the object code. Although assembler generate object code(.obj), assembly listing(.lst) and cross reference file(.crf), here Iam going to generate only the object code.
Further scope:
Although as a initial programmer in the field of assembler design I have taken a static example for this project, It can be develop on generalized assembler that will work for every source code that user will give as a input.
C code
//Design of assembler
#include<stdio.h>
#include<string.h>
#include<conio.h>
#include<stdlib.h>
void print(char *p,int loc,int len,char ra);
void main()
{
char *p[9][4] = {{"PRG1","START","",""},
                                   {"","USING","*","15"},
                                   {"","L","1","FIVE"},
                                   {"","A","1","FOUR"},
                                   {"","ST","1","TEMP"},
                                {"FOUR","DC","F'4'",""},
                                {"FIVE","DC","F'5'",""},
                                {"TEMP","DS","1F",""},
                                {"","END","",""}};
                int i,j=0,location_counter=0;
                int regno;
                clrscr();
                printf("\n");
                printf("   Source code in assembly language is as follows:\n");
                printf("------------------------------------------------------\n");
                for (i=0;i< 9;i++)
                {
                for(j=0;j< 4;j++)
                 {
                    printf("%s\t",p[i][j]);
                 }
                    printf("\n");
                }
                getch();
                printf("\n\nPress enter to get the symbol for above assembly code.\n");
                getch();
                printf("\n Symbol Table:\n ");
                printf("\nSYMBOL\tVALUE\tLENGTH\tRelocatable/Absolute\n");
                printf("---------------------------------------------\n");
                /*code for symbol table*/
                for(i=0;i< 9;i++)
                { if(strcmp(p[i][1],"START")==0)
                   {
                    print(p[i][0],location_counter,1,'R');
                    }
                    else if(strcmp(p[i][0],"")!=0)
                    {
                                print(p[i][0],location_counter,4,'R');
                                location_counter=4+location_counter;
                    }
                    else if(strcmp(p[i][1],"USING")==0)
                    {
                    }
                    else
                    {
                    location_counter=4+location_counter;
                    }
                }
                printf("----------------------------------------\n");
                                getch();
                                clrscr();
                //code for literal table
                printf("\n\nPress enter to get the literal table for above assembly code.\n");
                getch();
                printf("\n Literal Table:\n ");
                printf("\nLiteral\tVALUE\tLENGTH\tRelocatable/Absolute\n");
                printf("---------------------------------------------\n");
                location_counter=0;
                for(i=0;i<9;i++)
                {
                  if((strcmp(p[i][2],"F'4'")==0)||(strcmp(p[i][2],"F'5'")==0))
                  {
                                print(p[i][2],location_counter,4,'R');
                                location_counter=4+location_counter;
                  }
                     else if((strcmp(p[i][0],"")==0)&&(strcmp(p[i][1],"USING")!=0))
                    {
                                location_counter=4+location_counter;
                    }
                }
                printf("-----------------------------------------------");
getch();
/* code for base table */
 printf("\nPress enter to get the Base table for above assembly code.\n");
                getch();
                printf("\n Base Table:\n ");
                printf("\nReg.No\t Avalibility Indicator\t Content of base Reg.\n");
                printf("\t(1 byte character) \t\n");
                printf("------------------------------------------------------\n");
                regno=0;
                for(i=0;i<=15;i++)
                {
                  if(regno!=15)
                  {
                                printf("%d\t\t'N'\t\t -\n",regno);
                                regno++;
                  }
                     else
                    {
                      printf("%d\t\t'Y' \t\t\n ",regno);
                    }
                }
                printf("-------------------------------------------------------");
getch();
}
//-----------------------------------------
void print(char *p,int loc,int len,char ra)
{
printf("%s\t%d\t%d\t%c\n",p,loc,len,ra);

}
##End##