CAT BANK ATM - COBOL Implementation

A retro-style ATM system written in COBOL with a cat theme. Manage accounts, check balances, deposit and withdraw funds with a cat-themed interface.

Features

• Idle Screen: Welcome display with ASCII art
• User Authentication: Account number and PIN validation
• Account Management:
  • Balance inquiry
  • Deposit funds
  • Withdraw funds
• Session Management: Login/logout with secure card ejection
• System Shutdown: Graceful system power-down

Test Accounts

Account	PIN	Name	Balance
12345	1111	MR. WHISKERS	$1,000.50
88888	1985	DR. E. BROWN	$5,000,000.00
54321	0000	MARTY MCFLY	$10.00

Usage

Starting the Program

cobol ATM.cob
./ATM

Main Flow

1. Idle Screen - Press ENTER to start or 9 to shutdown
2. Login - Enter account number (5 digits) and PIN (4 digits)
3. Main Menu - Select operation:
   • 1 - Check balance
   • 2 - Deposit funds
   • 3 - Withdraw funds
   • 4 - Logout and eject card
   • 9 - Shutdown system

Operations

Balance Inquiry

• Displays current account balance in currency format

Deposit Funds

• Enter amount to add to account
• Balance updates immediately

Withdraw Funds

• Enter amount to withdraw
• System validates sufficient funds
• Displays updated balance

Logout

• Ejects card and returns to idle screen
• Can login with different account

Program Structure

MAIN-LOGIC
├── INIT-DB (Initialize test accounts)
├── DISPLAY-IDLE-SCREEN (Welcome screen)
├── LOGIN-SCREEN (Authentication)
│   └── AUTHENTICATE-USER (Verify credentials)
├── MAIN-MENU (Transaction menu)
│   ├── SHOW-BALANCE
│   ├── DEPOSIT-FUNDS
│   ├── WITHDRAW-FUNDS
│   └── LOGOUT-USER
└── System Shutdown

Data Structure

Account Database

• Account Number (5 digits)
• PIN (4 digits)
• Balance (7 digits + 2 decimals)
• Name (20 characters)

Session State

• Current user index
• Login status
• Shutdown flag

Error Handling

• Invalid account format detection
• Invalid PIN format detection
• Insufficient funds validation
• Invalid menu selection handling
• Invalid amount input validation

Security Features

• PIN-based authentication
• Session state management
• Secure logout with card ejection
• Input validation on all numeric fields

Customization

Add New Accounts

Edit INIT-DB section to add more test accounts:

MOVE 99999 TO DB-ACCT-NUM(4)
MOVE 2024  TO DB-PIN(4)
MOVE 5000.00 TO DB-BALANCE(4)
MOVE "YOUR NAME           " TO DB-NAME(4)

Modify Account Limits

Change ACCOUNT-DB OCCURS value to support more accounts

Adjust Balance Format

Modify DISPLAY-MONEY PIC $$$$,$$9.99 for different currency display

Author

ANDY - SOLVARSAURUS GITHUB