Practical – 6
AIM: Write a program to implement PASS 1 of a two pass Assembler.
#include<stdio.h>
#include<conio.h>
#include<string.h>
#include<stdlib.h>
#include<ctype.h>
struct symtab
{
char sym[10];
int symadd;
};
struct symtab st[20];
void main()
{
char opcode[10],mnemonic[3],op1[10],op2[10],label[10],code[10],ic[10];
int locctr,start,length,symcnt=0,symid=0;
FILE *finput,*foutput,*fsymtab,*foptab;
clrscr();
finput=fopen("C:/SP_Prog/SP/INPUT.txt","r");
fsymtab=fopen("C:/SP_Prog/SP/SYMTAB.txt","w");
foutput=fopen("C:/SP_Prog/SP/OUTPUT.txt","w");
foptab=fopen("C:/SP_Prog/SP/OPTAB.txt","r");
fscanf(finput,"%s%s%s%s",label,opcode,op1,op2);
char icop1[10],icop2[10];
if(strcmp(opcode,"START")==0)
{
start=atoi(op1);
locctr=start;
strcpy(icop1,"(C,");
strcat(icop1,op1);
strcat(icop1,")");
fprintf(foutput,"%s\t\t%s\t\t%s\n","(AD-01)",icop1,"");
fscanf(finput,"%s%s%s%s",label,opcode,op1,op2);
}
else
locctr=0;
int i;
