BBS Nostalgia Simulator

An authentic 1990s BBS (Bulletin Board System) dial-up experience in your browser. Features character-by-character ANSI art streaming at simulated modem speeds with automatic rotation through 731 classic BBS welcome screens.

Live Demo: bbs.nitwit.se

Features

• 731 ANSI Art Files - Classic BBS welcome screens from the 1990s
• Authentic Modem Simulation - ATZ, ATDT dial sequences, and NO CARRIER disconnect
• Variable Baud Rates - 2400, 9600, or 28800 baud based on file size
• IBM EGA Graphics - Authentic DOS font and 16-color palette
• CRT Effects - Scanline overlay for authentic terminal feel
• Lazy Loading - Fast initial load (~60KB), on-demand chunk loading
• Auto-Rotation - Automatically connects to random BBS after each session

Tech Stack

Modern (2025):

• ES6+ modules with async/await
• Vite 5 build system
• @xterm/xterm 5.5.0 terminal emulator
• Lazy-loaded JSON chunks
• Zero dependencies (no jQuery)

Preserved Authenticity:

• CP437 (DOS) character encoding
• IBM EGA color palette
• Original timing and baud rate simulation
• Character-by-character rendering

Project Structure

bbsss/
├── src/                      # Source code
│   ├── main.js              # Application entry point
│   ├── terminal/            # Terminal configuration & CP437 mapping
│   ├── modem/               # Modem simulation sequences
│   ├── renderer/            # ANSI rendering & timing
│   ├── ui/                  # Status bar & UI updates
│   └── data/                # ANSI data loader
├── public/                   # Static assets
│   ├── data/                # JSON chunks (generated)
│   ├── fonts/               # IBM EGA fonts
│   └── scanlines.png        # CRT effect overlay
├── ansi/                     # Source ANSI files (731 files)
├── dist/                     # Production build output
├── generate.py              # Generate JSON chunks from ANSI files
├── package.json
└── vite.config.js

Quick Start

Prerequisites

• Node.js 18+
• Python 3 (for regenerating data)

Development

# Install dependencies
npm install

# Start dev server (http://localhost:3000)
npm run dev

# Build for production
npm run build

# Preview production build (http://localhost:4173)
npm run preview

Regenerating ANSI Data

If you add/remove ANSI files in the ansi/ directory:

python3 generate.py

This creates:

• public/data/index.json - File index (57KB)
• public/data/chunk-*.json - Data chunks (8 files, ~600KB each)

Deployment

Deploy to Static Host

The dist/ directory contains everything needed:

npm run build
# Upload contents of dist/ to your web server

What gets deployed:

• index.html - Entry point
• assets/ - Bundled JS (~296KB) and CSS (~4KB)
• data/ - JSON chunks (8 files, ~5MB total)
• fonts/ - IBM EGA fonts
• scanlines.png - CRT overlay

Deploy to GitHub Pages

npm run build
# Push dist/ contents to gh-pages branch

Using with macOS Screen Saver

The screen saver can load the website directly from bbs.nitwit.se:

1. Configure your web-based screen saver to point to https://bbs.nitwit.se
2. The application will auto-rotate through BBS systems
3. Works offline if you deploy dist/ locally

Performance

Bundle Size

• Initial Load: 75KB gzipped (JS + CSS)
• First ANSI: +57KB (index.json) + ~600KB (one chunk)
• Total Assets: ~5.4MB (all chunks + fonts)

Load Time Comparison

Before modernization:

• 5.5MB embedded ANSI data loaded immediately
• Slow initial page load

After modernization:

• ~60KB initial load (98% reduction!)
• Chunks loaded on-demand
• Sub-second initial render

Architecture Highlights

Lazy Loading

// Load index once (57KB)
const index = await loadIndex();

// Select random file
const file = index.files[randomIndex];

// Load only needed chunk (~600KB)
const chunk = await loadChunk(file.chunk);

Async Flow

async function BBSLoop() {
  await delay(200 * timeScale);
  await writePreamble(terminal, baudRate, timeScale);
  await writeWithDelay(terminal, content, 24, timeScale);
  await writePostamble(terminal, timeScale);
  window.location.reload();
}

Module Organization

• terminal/ - Configuration, CP437 encoding
• modem/ - Preamble/postamble sequences
• renderer/ - Character streaming, timing
• ui/ - Status bar, clock
• data/ - ANSI loading with caching

Configuration

Edit src/terminal/config.js to customize:

export const BAUD_RATES = {
  SLOW: 2400,    // For files < 3000 bytes
  MEDIUM: 9600,  // For files 3000-10000 bytes
  FAST: 28800    // For files > 10000 bytes
};

export const FILE_SIZE_THRESHOLDS = {
  SMALL: 3000,
  LARGE: 10000
};

Browser Support

• Chrome/Edge 90+
• Firefox 88+
• Safari 14+

Requires ES6 modules and async/await support.

Credits

• ANSI art from textfiles.com
• Terminal emulation by xterm.js
• IBM EGA fonts recreated for web

License

ISC

Modernization Journey

This codebase was modernized from a 2010s-era hack into clean, maintainable 2025 code:

Phase 1: Vite + ES6 modules Phase 2: Removed jQuery, extracted modules Phase 3: Converted callbacks to async/await Phase 4: Lazy-loaded JSON chunks (98% size reduction) Phase 5: Upgraded to xterm.js v5.5.0 Phase 6: Production build & testing

See git history for the complete transformation!