CARL16 Computer

A fun summer project 2025 with the goal to build a simple 16-bit computer that can hold a simple OS, programming language and some games.

Project Structure

/chipset - Hardware Components

Hardware chipset for the Carl16 computer using a simple hardware descriptive language for the architecture of the logic gates.

The chipset is organized by complexity and dependencies:

Combinational Logic (/chipset/combinational)

• 1_basic/ - Fundamental gates (AND, OR, NOT, XOR, etc.)
• 2_adders/ - Arithmetic components (HalfAdder, FullAdder, Add16)
• 3_routing/ - Data routing (Mux, DMux and their variants)
• 4_logic/ - Complex logic units (ALU, Inc16)

Sequential Logic (/chipset/sequential)

• 1_storage/ - Basic memory (Bit, Register)
• 2_memory/ - Memory hierarchy (RAM8, RAM16, RAM512, RAM4K, RAM16K, Memory)
• 3_control/ - Control flow (Program Counter)
• 4_processing/ - Central components (CPU, Computer)

C16 Assembly Language

/assembler - C16 Assembler (Rust)

The Carl16 computer uses C16 assembly language, a simple assembly language with:

• 16-bit instructions
• Memory-mapped I/O
• Screen memory (addresses 0x4000-0x5FFF)
• Keyboard input (address 0x6000)

The assembler is implemented in Rust and includes:

• src/ - Assembler source code
• tests/ - C16 assembly test programs
  • basic.asm - Basic load/store operations
  • add.asm - Addition of two numbers
  • multiply.asm - Multiplication via repeated addition
  • branching.asm - Conditional branching
  • iteration.asm - Loop iteration and summation
  • variables.asm - Variable manipulation and swapping
  • pointers.asm - Array manipulation with pointers
  • screen.asm - Screen drawing operations
  • rectangle.asm - Interactive screen filling

Building the Assembler

cd assembler
cargo build --release

Resources

Based on concepts from "The Elements of Computing Systems" by Nisan and Schocken.