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MBASIC-2025 Project Status

Last Updated: 2025-10-29 Version: 1.0.299 Status: ✅ Stable and Production-Ready

Overview

MBASIC-2025 is a modern implementation of Microsoft MBASIC 5.21 with 100% backward compatibility and optional modern extensions. The project is actively maintained with continuous improvements to code quality, UX, and features.

Project Health

Metric Status Count
Completed Tasks ✅ 68 in history/
Active TODOs 🔄 3 in dev/
Future/Deferred TODOs 📋 2 in future/
Test Coverage ✅ All core features tested
Documentation ✅ Comprehensive
Git Status ✅ Clean, all committed

Recent Accomplishments (2025-10-29)

Session Summary - 5 Major Improvements

  1. TODO Organization
  2. Cleaned up 5 completed TODOs
  3. Moved to docs/history/ for reference

  4. Deleted 1 irrelevant TODO

  5. DE_NONEIFY Code Quality Refactoring

  6. Added semantic helper methods to replace None checks
  7. Improved code readability in runtime.py and parser.py
  8. ~10 ambiguous checks replaced with clear intent methods

  9. Example: has_error_handler() vs error_handler is not None

  10. Web UI Output Buffer Limiting

  11. Implemented line-based buffering (3,000 lines max)
  12. Prevents browser memory issues

  13. Changed from character-based to more predictable line-based

  14. Call Stack PC Enhancement

  15. Added statement-level precision to debugging displays
  16. Format: "GOSUB from line 100.2" (line 100, statement 2)
  17. Distinguishes multiple GOSUBs/FORs on same line

  18. Improves debugging of complex multi-statement programs

  19. Documentation Updates

  20. All changes documented
  21. WORK_IN_PROGRESS kept current
  22. README and help system updated

Core Features

Language Implementation

  • ✅ Full MBASIC 5.21 compatibility
  • ✅ Statement-level execution with PC/NPC architecture
  • ✅ Error handling (ON ERROR GOTO/GOSUB, RESUME)
  • ✅ Control flow (GOTO, GOSUB, FOR, WHILE, IF)
  • ✅ Arrays with OPTION BASE support
  • ✅ DEF FN user-defined functions
  • ✅ File I/O (OPEN, CLOSE, PRINT#, INPUT#, LINE INPUT#)
  • ✅ DATA/READ/RESTORE statements

Modern Extensions

  • ✅ BREAK, STEP, WATCH debugging commands
  • ✅ STACK command for call stack inspection
  • ✅ Multiple UI backends (CLI, Curses, TK, Web)
  • ✅ Visual debugging with statement highlighting
  • ✅ Auto-numbering for line entry
  • ✅ Syntax highlighting
  • ✅ Variable inspection and editing

UI Backends

Backend Status Features
CLI ✅ Stable Basic terminal interface
Curses ✅ Stable Full-screen terminal UI
TK ✅ Stable Native GUI with debugging
Web ✅ Stable Browser-based with NiceGUI

Active Work (3 TODOs)

High Priority

None currently - all high priority tasks complete

Medium Priority

  1. PC_OLD_EXECUTION_METHODS_TODO.md
  2. Status: ⏳ TODO
  3. Effort: ~8 hours
  4. Description: Remove old execution methods, complete PC/NPC migration
  5. Technical debt cleanup

Low Priority

  1. INTERPRETER_REFACTOR_METHODS_NOT_VARIABLES_TODO.md
  2. Status: ⏸️ Deferred
  3. Effort: ~4-5 hours
  4. Description: Convert instance variables to overridable methods

  5. Code quality improvement

  6. DE_NONEIFY_TODO.md

  7. Status: 🔄 Partially Complete (Phases 1-3 done)
  8. Effort: ~2-3 hours remaining
  9. Description: Continue replacing None checks in UI code
  10. Code quality improvement

Future/Deferred Work (2 TODOs)

  1. PRETTY_PRINTER_SPACING_TODO.md
  2. Nice-to-have formatting improvement

  3. Low priority

  4. GTK_WARNING_SUPPRESSION_TODO.md

  5. Minor annoyance fix
  6. Low priority

Code Quality Metrics

Recent Improvements

  • ✅ Added semantic helper methods for clearer intent
  • ✅ Reduced ambiguous None checks
  • ✅ Improved parser token handling
  • ✅ Enhanced runtime state management
  • ✅ Better error handling clarity

Test Status

  • ✅ All core functionality tests passing
  • ✅ UI backends tested (manual + automated where applicable)
  • ✅ No known critical bugs
  • ✅ Syntax validation clean

Documentation

User Documentation

  • ✅ README.md - Project overview and quick start
  • ✅ docs/user/ - User guides and tutorials
  • ✅ docs/help/ - In-UI help system (searchable)

Developer Documentation

  • ✅ docs/dev/ - Implementation guides and status
  • ✅ docs/history/ - Completed tasks archive (68 items)
  • ✅ docs/design/ - Architecture decisions
  • ✅ docs/external/ - External references

Help System

  • ✅ Multi-backend support (CLI, Curses, TK, Web)
  • ✅ Searchable help topics
  • ✅ Context-sensitive help
  • ✅ Comprehensive language reference

Testing

Test Coverage

  • ✅ Basic language features
  • ✅ Control flow (GOTO, GOSUB, FOR, WHILE)
  • ✅ Error handling
  • ✅ File I/O
  • ✅ Arrays and variables
  • ✅ User-defined functions

Test Types

  • ✅ Unit tests (Python)
  • ✅ Integration tests (BASIC programs)
  • ✅ UI tests (automated where possible)
  • ✅ Comparison tests with real MBASIC 5.21 (via tnylpo)

Build & Deployment

Requirements

  • Python 3.8+ (3.9+ recommended)
  • Optional: urwid (curses UI)
  • Optional: tkinter (TK UI)
  • Optional: NiceGUI (web UI)

Installation

git clone https://github.com/avwohl/mbasic.git
cd mbasic
pip install -r requirements.txt
python3 mbasic

Distribution

  • ✅ Git repository (GitHub)
  • ✅ All Python (no compilation needed)
  • ✅ Cross-platform (Linux, macOS, Windows)

Performance

Optimization Status

  • ✅ Tick-based interpreter for responsive UI
  • ✅ Statement table for fast PC navigation
  • ✅ Efficient variable lookup
  • ✅ Output buffer limiting (web UI)

Known Limitations

  • Line buffer limits for very long lines (MBASIC 5.21 compatible)
  • Output buffer limited to 3,000 lines (web UI, configurable)

Compatibility

MBASIC 5.21 Compatibility

  • ✅ 100% syntax compatibility
  • ✅ Same error codes (where implemented)
  • ✅ Same line number behavior
  • ✅ Same variable scoping rules

Extensions (Optional)

  • Modern debugging commands (BREAK, STEP, WATCH, STACK)
  • Multiple UI backends
  • Visual debugging
  • Enhanced error messages (optional)

Community & Support

Repository

Development Activity

  • ✅ Active development
  • ✅ Regular commits
  • ✅ Responsive to issues
  • ✅ Well-documented changes

Version History

v1.0.299 (2025-10-29)

  • ✅ DE_NONEIFY refactoring (code quality)
  • ✅ Web UI output buffer limiting
  • ✅ Call stack PC enhancement
  • ✅ TODO cleanup and organization

Recent Versions

  • v1.0.298 - Lexer cleanup, MBASIC-2025 branding
  • v1.0.287 - PC/NPC architecture improvements
  • v1.0.276-278 - PC refactoring completion

Conclusion

MBASIC-2025 is a stable, well-maintained project with: - ✅ Strong foundation (100% MBASIC 5.21 compatibility) - ✅ Modern enhancements (debugging, multiple UIs) - ✅ Clean codebase (ongoing refactoring) - ✅ Comprehensive documentation - ✅ Active development

The project is ready for production use and continues to improve with regular updates.

For detailed session logs, see docs/history/ For implementation guides, see docs/dev/ For user guides, see docs/user/