Ajinkya Mandhare: Assemblers

Programs for Pass1 assembler:
1. Pass 1(a):

import java.io.*;
import java.util.*;
class Pass1a
{public static void main(String args[])throws IOException
{
int i=0;
FileWriter fw=new FileWriter("Input.txt");
Scanner src=new Scanner(System.in);
System.out.println("Enter code");
String code=src.next();
char code1[]=new char[500];
code1=code.toCharArray();
int n=code.length();

for( i=0;i<n;++i)
{
while((code1[i]!='|')&&i<n-1)
{
if(code1[i]==';')
{fw.write("\n");
++i;
continue;

}
fw.write(code1[i]);
++i;
}
fw.write(" ");
}

fw.close();
FileReader fr=new FileReader("Input.txt");
BufferedReader br=new BufferedReader(fr);
String input;
while((input=br.readLine())!=null)
System.out.println(input);
String token="";
i=0;
String prg[][] = new String[30][4];
int lines=0;
input="";
FileReader fr1=new FileReader("Input.txt");
BufferedReader br1=new BufferedReader(fr1);

while((input=br1.readLine())!=null)
{
int l=input.length();
i=0;
token = "";

while(i<l)
{
		if(input.charAt(i)!=' ')
			token+=input.charAt(i);
		else break;
			i++;
}

if(token=="") token="   ";
	prg[lines][0]=token;

token = "";

while(i<l)
		if(input.charAt(i)==' ')
		i++;
		else break;

while(i<l)
	{
		if(input.charAt(i)!=' ')
			token+=input.charAt(i);
		else break;
		i++;
	}

if(token=="") token=" ";
	prg[lines][1]=token;

while(i<l)
		if(input.charAt(i)==' ') 
		i++;
		else break;

token = "";

while(i<l)
	{
		if(input.charAt(i)!=' ' && input.charAt(i)!=',')
			token+=input.charAt(i);
		else break;
		i++;
	}

if(token=="") token=" ";
	prg[lines][2]=token;

while(i<l)
		if(input.charAt(i)==' ' || input.charAt(i)==',') i++;
		else break;

token = "";

while(i<l)
	{
		if(input.charAt(i)!=' ')
			token+=input.charAt(i);
		else break;
		i++;
	}

if(token=="") token="";
	prg[lines][3]=token;

lines++;
	i=l;

}
int j;

System.out.println("\n");
for(i=0;i<lines;i++)
{
	for(j=0;j<4;j++)
		System.out.print(prg[i][j]+"\t");
	System.out.println();
}

}}

2. Pass 1(b):

import java.io.*;
import java.util.*;
class Pass1b
{public static void main(String args[])throws IOException
{
int i=0;
FileWriter fw=new FileWriter("Input.txt");
Scanner src=new Scanner(System.in);
System.out.println("Enter code");
//int n=src.nextInt();
//St s[]=new St[n];
String code=src.next();
char code1[]=new char[500];
code1=code.toCharArray();
//for(int i=0;i<10;++i)
//System.out.println(code1[i]);
int n=code.length();
System.out.println(n);

for( i=0;i<n;++i)
{
while((code1[i]!='|')&&i<n-1)
{
if(code1[i]==';')
{fw.write("\n");
++i;
continue;

}
//System.out.println(i);
fw.write(code1[i]);
++i;
}
fw.write(" ");
}

fw.close();
FileReader fr=new FileReader("Input.txt");
BufferedReader br=new BufferedReader(fr);
String input;
while((input=br.readLine())!=null)
System.out.println(input);
//fr.close();
String token="";
i=0;
String prg[][] = new String[30][4];
int lines=0;
input="";
FileReader fr1=new FileReader("Input.txt");
BufferedReader br1=new BufferedReader(fr1);

while((input=br1.readLine())!=null)
{
int l=input.length();
i=0;
token = "";

while(i<l)
{
		if(input.charAt(i)!=' ')
			token+=input.charAt(i);
		else break;
			i++;
}

if(token=="") token=" ";
	prg[lines][0]=token;

token = "";

while(i<l)
		if(input.charAt(i)==' ') i++;
		else break;

while(i<l)
	{
		if(input.charAt(i)!=' ')
			token+=input.charAt(i);
		else break;
		i++;
	}

if(token=="") token=" ";
	prg[lines][1]=token;

while(i<l)
		if(input.charAt(i)==' ') i++;
		else break;

token = "";

while(i<l)
	{
		if(input.charAt(i)!=' ' && input.charAt(i)!=',')
			token+=input.charAt(i);
		else break;
		i++;
	}

if(token=="") token=" ";
	prg[lines][2]=token;

while(i<l)
		if(input.charAt(i)==' ' || input.charAt(i)==',') i++;
		else break;

token = "";

while(i<l)
	{
		if(input.charAt(i)!=' ')
			token+=input.charAt(i);
		else break;
		i++;
	}

if(token=="") token="";
	prg[lines][3]=token;

lines++;
	i=l;

}
int j;
System.out.println("\n");
for(i=0;i<lines;i++)
{
	for(j=0;j<4;j++)
		System.out.print(prg[i][j]+"\t");
	System.out.println();
}

String mnemonics[] = new String[10];
int mlen[] = new int[10];
int mno = 0;

mnemonics[mno]="L";
mlen[mno++]=4;
mnemonics[mno]="A";
mlen[mno++]=4;
mnemonics[mno]="ST";
mlen[mno++]=4;

String pseudo[] = new String[10];
int pno=0;

pseudo[pno++]="START";
pseudo[pno++]="BALR";
pseudo[pno++]="USING";
pseudo[pno++]="DC";
pseudo[pno++]="DS";
pseudo[pno++]="END";

System.out.println();
System.out.println("-------------------------------------------");
System.out.println("Mnemonics opcode Table is : ");
System.out.println();

System.out.println("Mnemonics\tLength");
System.out.println();

for(i=0;i<mno;i++)
{
	System.out.print(mnemonics[i]+"\t\t  "+mlen[i]);
	System.out.println();
}

System.out.println();
System.out.println("-------------------------------------------");
System.out.println("Pseudo opcode Table is : ");
System.out.println();

System.out.println("Psuedo\tRoutine Adderess");
System.out.println("Opcode");
System.out.println();

for(i=0;i<pno;i++)
{
	System.out.print(pseudo[i]+"\t\t"+i);
	System.out.println();
}

String symbol[] = new String[20];
int sym_value[] = new int[20];
int symno = 0;

int lc=0;
for(i=0;i<lines;i++)
{
	token = prg[i][0];
	if(token!=" ")
	{
		symbol[symno] = token;
		sym_value[symno++] = lc;
	}

token = prg[i][1];

if(token.equalsIgnoreCase("DC")) lc=lc+4;
	else if(token.equalsIgnoreCase("DS")) lc=lc+4;
	else
	{
		for(j=0;j<mno;j++)
		{
			if(token.equals(mnemonics[j])) 
			{
				lc=lc+mlen[j];
				break;
			}
		}
	}

}

System.out.println();
System.out.println("-------------------------------------------");
System.out.println("Symbol Table is : ");
System.out.println();

System.out.println("Symbol\tValue");
System.out.println();

for(i=0;i<symno;i++)
{
	System.out.print(symbol[i]+"\t"+sym_value[i]);
	System.out.println();
}
}}

3. Pass 1(c):

import java.io.*;
import java.util.*;
class Pass1c
{public static void main(String args[])throws IOException
{
int i=0;
FileWriter fw=new FileWriter("Input.txt");
Scanner src=new Scanner(System.in);
System.out.println("Enter code with | as space & ; for next line");
String code=src.next();
char code1[]=new char[500];
code1=code.toCharArray();
int n=code.length();

for( i=0;i<n;++i)
{
while((code1[i]!='|')&&i<n-1)
{
if(code1[i]==';')
{fw.write("\n");
++i;
continue;

}
fw.write(code1[i]);
++i;
}
fw.write(" ");
}

while((input=br1.readLine())!=null)
{
int l=input.length();
i=0;
token = "";

while(i<l)
{
		if(input.charAt(i)!=' ')
			token+=input.charAt(i);
		else break;
			i++;
}

if(token=="") token=" ";
	prg[lines][0]=token;

token = "";

while(i<l)
		if(input.charAt(i)==' ') i++;
		else break;

while(i<l)
	{
		if(input.charAt(i)!=' ')
			token+=input.charAt(i);
		else break;
		i++;
	}

if(token=="") token=" ";
	prg[lines][1]=token;

while(i<l)
		if(input.charAt(i)==' ') i++;
		else break;

token = "";

while(i<l)
	{
		if(input.charAt(i)!=' ' && input.charAt(i)!=',')
			token+=input.charAt(i);
		else break;
		i++;
	}

if(token=="") token=" ";
	prg[lines][2]=token;

while(i<l)
		if(input.charAt(i)==' ' || input.charAt(i)==',') i++;
		else break;

token = "";

while(i<l)
	{
		if(input.charAt(i)!=' ')
			token+=input.charAt(i);
		else break;
		i++;
	}

if(token=="") token="";
	prg[lines][3]=token;

lines++;
	i=l;

}
int j;
System.out.println("\n");
for(i=0;i<lines;i++)
{
	for(j=0;j<4;j++)
		System.out.print(prg[i][j]+"\t");
	System.out.println();
}

String mnemonics[] = new String[10];
int mlen[] = new int[10];
int mno = 0;

mnemonics[mno]="L";
mlen[mno++]=4;
mnemonics[mno]="A";
mlen[mno++]=4;
mnemonics[mno]="ST";
mlen[mno++]=4;

String pseudo[] = new String[10];
int pno=0;

pseudo[pno++]="START";
pseudo[pno++]="BALR";
pseudo[pno++]="USING";
pseudo[pno++]="DC";
pseudo[pno++]="DS";
pseudo[pno++]="END";

System.out.println();
System.out.println("-------------------------------------------");
System.out.println("Mnemonics opcode Table is : ");
System.out.println();

System.out.println("Mnemonics\tLength");
System.out.println();

for(i=0;i<mno;i++)
{
	System.out.print(mnemonics[i]+"\t\t  "+mlen[i]);
	System.out.println();
}

System.out.println();
System.out.println("-------------------------------------------");
System.out.println("Pseudo opcode Table is : ");
System.out.println();

System.out.println("Psuedo\tRoutine Adderess");
System.out.println("Opcode");
System.out.println();

for(i=0;i<pno;i++)
{
	System.out.print(pseudo[i]+"\t\t"+i);
	System.out.println();
}

String symbol[] = new String[20];
int sym_value[] = new int[20];
int symno = 0;
String literal[] = new String[20];
int lit_value[] = new int[20];
int litno = 0;
String lit="";
int lc=0;
for(i=0;i<lines;i++)
{
	token = prg[i][0];
	lit=prg[i][2];
	if(lit!="")
	{
	if(lit.charAt(0)=='=')
	{
   		literal[litno++] = lit;
 	}
	}

token = prg[i][1];

}

for(i=0;i<litno;i++)
{
lit=literal[i];

if(lit.charAt(1)=='F'||lit.charAt(1)=='f')
	{
   		lit_value[i] = lc;
		lc=lc+4;
	}

if(lit.charAt(1)=='H'||lit.charAt(1)=='h')
	{
   		lit_value[i] = lc;
		lc=lc+2;
	}

if(lit.charAt(1)=='D'||lit.charAt(1)=='d')
	{
   		lit_value[i] = lc;
		lc=lc+8;
	}
	
}
System.out.println();
System.out.println("-------------------------------------------");
System.out.println("Literal Table is : ");
System.out.println();

System.out.println("Literal\tValue");
System.out.println();

for(i=0;i<litno;i++)
{
	System.out.print(literal[i]+"\t"+lit_value[i]);
	System.out.println();
}

}}

NOTE:While entering the code use '|' as space & ';' for next line.