Exploring Jubin Mitra’s 8085 Simulator: A Journey into Microprocessor Simulation
Published: 2024-04-11 03:28:38

This Java-based program is an excellent tool for learning and simulating the Intel 8085 microprocessor. Whether you’re a student studying microprocessors or an enthusiast exploring assembly-level programming, this simulator provides a valuable platform to understand the architecture and practice coding.

Here’s a step-by-step guide to using Jubin Mitra’s 8085 Simulator:

**A. Download the Simulator:**

- [You can download the simulator from the official documentation.](https://www.java.com/en/download/manual.jsp)
- It runs on all operating systems (Linux/BSD and Windows).
- To run it on Linux/BSD, use the following command:
                 `java -jar 8085Compiler.jar`
- On Windows, ensure you have Java installed. Check this by typing _java -version_ into the command terminal. If you don’t have the latest version of Java, update it before proceeding. You can install Java (version >6) from [here](https://www.java.com/en/download/manual.jsp).
- Double-click the `.jar` file to execute it. Alternatively, you can run it via the Command Prompt using:
              `java -jar 8085Compiler.jar`
**B. Explore the Features:**

**1. Assembler Editor:**

- Load programs written in other simulators.
- Auto-correct and auto-indent features.
- Supports assembler directives.
- Specify parameters in binary, decimal, or hexadecimal format.
- Write comments and label instructions.
- Error checking and syntax highlighting.

**2. Disassembler Editor:**

- Supports loading Intel-specific hex file formats.
- Reverse trace the original program from assembly code.
- Syntax highlighting and auto spacing.

**3. Assembler Workspace:**

- Displays address fields, labels, mnemonics, hex codes, mnemonic size, M-cycles, and T-states.
- Supports static timing diagrams for all instruction sets.
- Dynamic timing diagram during step-by-step simulation.
- Error checking.

**4. Memory Editor:**

- Update data directly in specified memory locations.
- Choose from three interface options:
                   - Show entire memory content.
                   - Show only loaded memory locations.
                   - Store directly to specified memory locations.

**5. I/O Editor:**

- Necessary for peripheral interfacing.
- Enables direct editing of content.

**6. Interrupt Editor:**
Supports all possible interrupts (INTR, TRAP, RST 7.5, RST 6.5, RST 5.5).
Trigger interrupts by pressing the appropriate column on the interrupt table.
Reset simulation anytime by clearing memory in the settings tab.

**7. Debugger:**
Set breakpoints.
Step-by-step execution/debugging of programs.
Forward and backward traversal of programs.
Continue from breakpoints.

**8. Simulator:**

- **Three levels of simulation speed:**
         - **Step-by-step:** Automatic line-by-line execution with each line highlighted. User-defined halt time for each line.
         - **Normal:** Full execution with intermittent state reflections.
         - **Ultimate:** Full execution with direct final state reflection.
- **Two modes of simulator engine**:
         - **Run all at a Time:** Execution based on current speed settings.

**C. Learn and Experiment:**

- Load sample programs, explore the features, and practice coding.
- Use the simulator to understand microprocessor concepts playfully.


For more details, you can visit [the official GitHub page](https://github.com/8085simulator/8085simulator.github.io) or the [8085 Simulator website](https://learning-microprocessors.sourceforge.io/8085-simulator.html). Happy simulating! 🖥️🔍