🛒 Vending Machine Simulator (x86 Assembly)

A complete, menu-driven vending machine simulation written in x86 Assembly Language (MASM/TASM syntax). This project demonstrates low-level programming mastery by implementing a dual-mode system with a customer-facing interface and a secure admin backend, all in pure assembly.

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✨ Features

🧑‍💻 Customer Mode

• Browse Inventory: View available items, their prices, and stock levels.
• Make Purchases: Select items and specify desired quantity.
• Payment System: Accepts virtual cash inputs (20, 50, 100).
• Transaction Processing: Calculates bill, handles payment, and returns change.
• Friendly UI: Clear prompts and messages guide the user through the process.

🔐 Admin Mode (PIN: 1234)

• Secure Access: Protected by a 4-digit PIN code.
• View Total Sales: Displays the total revenue generated from all transactions.
• Low Stock Alerts: Intelligently scans and lists all items with a quantity below 5.
• Dynamic Inventory Management:
  • Update Any Item: Change the price and stock quantity of any product in real-time.
  • Live Editing: Modifications are immediately reflected in the customer mode.

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🚀 Why This Project is Cool

• Pure Assembly: It's not just a "Hello World"; it's a complex application pushing the limits of what's possible in ASM.
• Real-World Concepts: Implements core CS concepts like memory management, arithmetic operations, string handling, and control flow at the hardware level.
• Dual-Interface Design: Showcases structured programming in a low-level environment with separate modes for different users.
• Perfect for Learning: An excellent codebase for students and enthusiasts to understand how high-level logic translates down to assembly.

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🛠️ How to Run

Prerequisites

You need an 8086 assembler and emulator. We recommend:

• MASM (Microsoft Macro Assembler) or TASM (Turbo Assembler)
• DOSBox to emulate a 16-bit environment on modern systems.

Instructions

1. Clone this repository or download the .asm file.
2. Mount your project directory in DOSBox.
3. Assemble and link the program:

   masm vending.asm;
   link vending.obj;

   or for TASM:

   tasm vending.asm
   tlink vending.obj

4. Run the executable: vending.exe

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📁 Code Overview

Label	Description
NewLine	Prints a carriage return and line feed.
PrintWordDecimal	Converts and prints a word-sized integer to decimal.
AdminCheck	Validates the admin PIN.
ShowTotalSales	Feature #5.1: Prints the total_sell value.
ShowLowStock	Feature #5.2: Lists items with quantity < 5.
UpdateItems	Feature #6: Allows updating an item's price and quantity.
Calculate_bill	Multiplies item price by quantity and stores the result.

Key Data Structures:

• item_name: Array of strings (6 bytes each).
• item_price, item_quantity: Parallel byte arrays.
• total_sell, bill, cash: Word variables for financial tracking.

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🤝 Contributing

Contributions are welcome! If you have ideas for new features (e.g., a better UI, more items, a password change function), feel free to fork the repo and submit a pull request.

1. Fork the Project
2. Create your Feature Branch (git checkout -b feature/AmazingFeature)
3. Commit your Changes (git commit -m 'Add some AmazingFeature')
4. Push to the Branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

⭐ If You Like This...

If you find this project interesting or useful, please give it a star ⭐ on GitHub! It helps others discover it and motivates further development.