8086 Serial Chat 📃

8086 Serial Chat is a bi-directional communication program written in 8086 Assembly language. It allows real-time text-based communication between two machines or terminals connected through the serial port (UART). The program splits the screen into two sections for input and output, simulating a basic "chat window."

Features

• Screen Division: The display is divided into two sections:
  • Top Section: Your input (typed text).
  • Bottom Section: Received messages from the serial port.
• Serial Communication: Data is transmitted and received using UART (Universal Asynchronous Receiver/Transmitter).
• Scrolling: Automatically scrolls text when the screen reaches its limit.
• Exit Option: Press ESC to gracefully exit the program.

Prerequisites

To run this program, you'll need the following:

1. DOSBox-X: A DOS emulator with enhanced features. Download it here.
2. Python: To automate running the program.
3. A compatible assembler:
   • TASM (Turbo Assembler)
   • MASM (Microsoft Macro Assembler)

Installation

1. Clone the Repository:

   git clone https://github.com/yourusername/8086-Serial-Chat.git
   cd 8086-Serial-Chat

2. Set Up DOSBox-X:

   • Ensure DOSBox-X is installed on your computer and its path is configured properly.

3. Run the Program Using Python: The provided run.py script will automate launching the program in DOSBox-X:

   python run.py

   This script assembles the code (if needed) and executes the program seamlessly in DOSBox-X.

How It Works

• Initialization:

  • The program initializes the serial port for communication using standard UART configuration.
  • The screen is divided into two parts with a horizontal separator.

• Chat Input and Output:

  • Input: Type characters, which are transmitted to the connected terminal.
  • Output: Incoming characters are displayed in the lower section of the screen.

• Scrolling:

  • If text reaches the end of the screen, the program scrolls the display to keep the conversation flowing.

• Exit:

  • Press ESC to exit the program.

Program Flowchart

START
   │
   ├─► Clear Screen
   ├─► Draw Separator
   ├─► Initialize Serial Port
   │
   └─► MAIN LOOP
         ├─► Check for Incoming UART Data
         │    └─► Display Received Character
         │
         ├─► Check for Keyboard Input
         │    └─► Send Character to UART
         │
         └─► Check for Exit Command (ESC)
                 └─► EXIT

Keyboard Controls

• Type Text: Sends the text to the other terminal.
• Press ESC: Exits the program.

Customization

Baud Rate

The current program is set to a baud rate divisor of 0x0C for 9600 baud. Modify the following lines in INIT_SERIAL for other baud rates:

MOV DX, 3F8h
MOV AL, 0Ch  ; LSB of baud rate divisor (0x0C = 9600 baud)
OUT DX, AL

MOV DX, 3F9h
MOV AL, 00h  ; MSB of baud rate divisor
OUT DX, AL

Running with Python Script

The run.py script simplifies launching the program in DOSBox-X. Ensure the following:

1. DOSBox-X is installed and its executable is available in your system's PATH.

2. Run the script:

   python run.py

The script will assemble the program (if necessary) and open DOSBox-X to execute it.

License

This project is released under the MIT License.