ABSOLUTE LOADER

AIM:

To perform the operation of absolute loader.

ALGORITHM:

Step 1: Start the program.

Step 2: Set an array for text, opcode and object code.

Step 3: Read object program from the user.

Step 4: If the record type is header record, set the starting address of the program.

Step 5: If the record type is TEXT record, the object code is placed ion the corresponding memory address.

Step 6: If the word type is END record, the control is transferred to beginning of program.

Step 7: Stop the program.

SOURCE CODE:

/* ABSOLUTE LOADER */

#include<stdio.h>

#include<conio.h>

#include<string.h>

struct object

{

char text[10],opcode[10];

}obj[10];

struct output

{

int addr;

char ob1,ob2;

}op[10];

void main()

{

int i,j,n,k,x,start=0,z;

clrscr();

i=0;

do

{

i++;

printf("\nEnter the text:");

scanf("%s",obj[i].text);

printf("\nEnter the object code:");

scanf("%s",obj[i].opcode);

//if(strcmp(obj[i].opcode);

if(strcmp(obj[i].text,"H")==0)

start=atoi(obj[i].opcode);

}

while(strcmp(obj[i].text,"E")!=0);

z=1;

printf("Address\tObject code\n");

for(k=1;k<i;k++)

{

if(strcmp(obj[k].text,"H")==0)

continue;

for(x=0;x<6;x+=2)

{

op[z].addr=start;

op[z].ob1=obj[k].opcode[x];

op[z].ob2=obj[k].opcode[x+1];

start++;

z++;

}

}

for(k=1;k<z;k++)

{

printf("\n%d\t%c%c",op[k].addr,op[k].ob1,op[k].ob2);

}

getch();

}

OUTPUT:

Enter the text:H

Enter the object code:1000

Enter the text:T

Enter the object code:123456

Enter the text:T

Enter the object code:904523

Enter the text:E

Enter the object code:1000

Address Object code

1000    12

1001    34

1002    56

1003    90

1004    45

1005    23

Result

Thus above program executed and output verified