About

Implementation of the first pass of the two-pass assembler in Java.

Pass 1 generates:

• Literal table
• Symbol table
• Pool table
• Intermediate code

A few assumptions are made for the assembly code input. Read them here.

Input and Output

Input is an assembly file (ending with asm extension) located in the input directory.
Output consists of 4 files in the output directory: literal table, symbol table, pool table, and intermediate code.

Sample Input

START 200
MOVER AREG, ='5'
MOVEM AREG, A
LOOP MOVER AREG, A  
MOVER CREG, B  
ADD CREG, ='1'
BC ANY, NEXT
LTORG
NEXT SUB AREG, ='1'
BC LT, BACK
LAST STOP
ORIGIN LOOP+2
MULT CREG, B
ORIGIN LAST+1
A DS 1
BACK EQU LOOP
B DS 1
END
    ='1'

Sample Output

1. Literal Table (literal_table.txt)

Literal Table:
ID   Literal    Address
1    ='5'       206    
2    ='1'       207    
3    ='1'       213

2. Symbol Table (symbol_table.txt)

Symbol Table:
ID   Symbol     Address
1    A          211    
2    LOOP       202    
3    B          212    
4    NEXT       208    
5    BACK       202    
6    LAST       210    
 

3. Pool Table (pool_table.txt)

Pool Table:
ID   Lit. ID  Pool Length
1    1        2          
2    3        1          

4. Intermediate Code (intermediate_code.txt)

(AD, 1) (C, 200) 
(IS, 4) (1) (L, 1) 
(IS, 5) (1) (S, 1) 
(IS, 4) (1) (S, 1) 
(IS, 4) (3) (S, 3) 
(IS, 1) (3) (L, 2) 
(IS, 7) (CC, 6) (S, 4) 
(AD, 5) 
(IS, 2) (1) (L, 3) 
(IS, 7) (CC, 2) (S, 5) 
(IS, 0) 
(AD, 3) 
(IS, 3) (3) (S, 3) 
(AD, 3) 
(DL, 1) (C, 1) 
(AD, 4) (S, 2) 
(DL, 1) (C, 1) 
(AD, 2)