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Getting Started with MBASIC

Welcome to MBASIC 5.21! This is a complete Python implementation of MBASIC-80 for CP/M.

What is MBASIC?

MBASIC 5.21 is a classic BASIC dialect from the CP/M era (late 1970s - early 1980s). This interpreter provides:

  • 100% MBASIC 5.21 compatibility - Runs authentic MBASIC programs
  • Modern interface - Choice of CLI, Curses, Tkinter, or Web UI
  • Cross-platform - Works on Linux, macOS, Windows
  • No dependencies - Pure Python implementation

Installation

Requirements

  • Python 3.8 or later
  • Optional: urwid for Curses UI (installed via pip install urwid)

Quick Install

# Clone the repository
git clone https://github.com/avwohl/mbasic.git
cd mbasic

# Create virtual environment (recommended)
python3 -m venv venv
source venv/bin/activate  # Windows: venv\Scripts\activate

# Install optional dependencies
pip install -r requirements.txt

# Run MBASIC
mbasic

Your First Program

Method 1: Interactive Mode (Curses UI)

Start MBASIC without arguments for the full-screen editor:

mbasic

Type your program:

10 PRINT "Hello, World!"
20 END

Press {{kbd:run:curses}} to run.

Method 2: File Mode

Create a file hello.bas:

10 PRINT "Hello, World!"
20 END

Run it:

mbasic hello.bas

Method 3: CLI Mode

Start MBASIC in CLI mode:

mbasic --ui cli

Type your program at the Ok prompt:

10 PRINT "Hello, World!"
20 END
RUN

Choosing a User Interface

MBASIC supports four interfaces:

Curses UI (Default)

Full-screen terminal interface with split editor/output:

mbasic               # or
mbasic --ui curses

Best for: Interactive program development, debugging

CLI Mode

Classic MBASIC command-line interface:

mbasic --ui cli

Best for: Scripting, automation, authentic MBASIC experience

Tkinter GUI

Graphical interface with menu bar and toolbar:

mbasic --ui tk

Best for: Users who prefer graphical interfaces

Web UI

Browser-based interface with modern IDE features:

mbasic --ui web

Best for: Remote access, collaborative development, modern web-based workflow

Next Steps

Quick Reference

Running programs: 

mbasic program.bas    # Run a file
mbasic                # Interactive mode

Common keyboard shortcuts (Curses UI): - {{kbd:run:curses}} - Run program - {{kbd:save:curses}} - Save program - {{kbd:open:curses}} - Open program - {{kbd:help:curses}} - Help - {{kbd:quit:curses}} - Quit

Common commands (CLI mode): - RUN - Execute program - LIST - Show program - SAVE "file.bas" - Save to disk - LOAD "file.bas" - Load from disk - NEW - Clear program - SYSTEM - Exit MBASIC

Getting Help