One-Pass Assembler

• Need for an Assembler
  • Computers cannot directly execute assembly language instructions; they require machine-readable object code.
  • Assemblers are used to convert human-readable assembly code into object code that can be executed by the machine.
  • A one-pass assembler is more efficient than a two-pass assembler, since it builds the symbol table and generates object code simultaneously.
  • Handling forward references (symbols used before being defined) is one of the major challenges in one-pass assembly.

• About the project
  • Implemented in C++ as part of a System Programming assignment.
  • Uses an OPTAB (Opcode Table) to map assembly mnemonics to machine opcodes.
  • Builds a SYMTAB (Symbol Table) to manage labels and addresses dynamically.
  • Handles forward references using backpatching techniques.
  • Supports assembler directives such as WORD, BYTE, RESB, RESW.
  • Generates object program records in the standard format:
    • Header Record (H)
    • Text Records (T)
    • End Record (E)

Read more about project on github.