PC Simulation

Basic Rust app that will simulate some of the flows on computer, including:

• RAM (256 bytes) - can be read, written and dumped for inspection.

  Addressed via hexadecimal addressed.

  Each memory cell is 8 bits (1 byte) wide

• CPU - Supports basic arithmetic and logic operations (ADD, AND, OR, NAND, NOR, XOR, NOT).

  ATM asm-like code directly executed by the CPU, I'm not sure how it supposed to be.

  CPU supports 8 general-purpose 8-bit registers to hold data during execution.

• More on the way, but it's still area for a research.

Simulation has option to write simple assembly-like programs with small set of instructions:

• VER - Toggle verbosity to enable/disable detailed execution logs.
• MOV QMOV - Assingning RAM/Another Register's/Immediate Value to the register
• INIT - Initialize memory addresses with values.
• LOAD - Load a value from memory into a register.
• ADD SUB MUL DIV - basic arythemitcs
• STORE - Store a value from a register into memory.
• OUT - Output register or memory/values.
• CLEAR - Clear the register or memory
• HALT - Stop the execution.
• IF/ELSE - If and else statement that supports basic operations between registers, memory and values.

While I'm aiming to make it as low-level and realistic as possible - some of the features jsut could't be realisied due to number of reasons, one of them - I'm still researching about flows and how everything is working.

Run asm-like code

BIOS> filename.asm

You can play around with some example programs:

• calculator.asm - Addition calculator program
• gates.asm - Test of the Logic Gates
• if_test.asm - Simple IF ELSE logic
• program.asm - Simple collection of different instructions
• mov_test.asm - Test of MOV instruction
• div.asm - Division Program
• incdec.asm - Increment and Decrement Register
• mul.asm - Multiplication Program
• qmov.asm - QMOV Test
• sub.asm - Substract Instruction

Program example

; Example program
VER = 1                    ; Enable debug (VERBOSE) prints of execution
INIT [0x08] = 0b00000101   ; Initialize memory at address 0x08 with binary 5
INIT [0x10] = 0b00001010   ; Initialize memory at address 0x10 with binary 10
INIT [0x1F] = 0b00001010

LOAD R1, [0x08]            ; Load value from address 0x08 into register R1
LOAD R2, [0x10]            ; Load value from address 0x10 into register R2
ADD R1, R2, R3             ; Add R1 and R2, store result in R3

STORE R3, [0x20]           ; Store the result in memory address 0x20

OUT R3                     ; Display the register R3

CLEAR [0x20]               ; Clear the value in memory address 0x20
CLEAR [0x08]               ; Clear the value in memory address 0x08
CLEAR [0x10]               ; Clear the value in memory address 0x10
CLEAR [0x1F]               ; Clear the value in memory address 0x1F

VER = 0                    ; Disable debug (VERBOSE) prints of execution
HALT                       ; Stop execution

Getting Started

1. Make sure you have rust installed
2. Clone the repo:

    git clone https://github.com/denver-code/pc_simulation_rs
    cd pc_simulation_rs

3. Run or Build the project:

    # Build
    cargo build --release (Optional)
    # Run
    cargo run

Usage

BIOS Commands

Once the simulator is powered on, you can use the following commands in the BIOS prompt:

- address [hex]: View the value stored in memory at the given address (in hexadecimal in square brackets).

- memory_dump: Display the entire contents of the RAM.
    
- exit: Quit the BIOS.

- [filename].asm: Load and run an assembly-like program from a file.