Serial bring-up & DOSBox workflow 📟

DOSCODE 0.1.0 — Serial bring-up & DOSBox workflow 📟

Second release of DOSCODE. This version focuses on getting the DOS
client to actually talk to the Python proxy over COM1, stabilizing the
serial protocol under QuickBasic 4.5, and documenting a reproducible
workflow with DOSBox + socat.

Architecture:
MS-DOS client ⇄ plain-text serial ⇄ Python proxy ⇄ HTTPS ⇄ LLM provider

✨ Highlights

• 🔌 Reliable serial in QuickBasic 4.5: byte-by-byte reads, PROMPT sent
  with explicit CRLF, and robust detection of the END marker.
• 🛠️ Safe RUN: confirmation prompt before executing any command and
  support for inline <RUN>...</RUN>, with control returning to the user
  after execution.
• 🖥️ Documented DOSBox workflow: nullmodem TCP ↔ PTY via socat, plus
  monitoring and symlink helper scripts for the mounted DOSBox folder.
• 🧠 More usable proxy: valid default models, fixed Claude auth header,
  and LLM line logging to stderr.
• 📚 Instruction bridges for AI agents: Cursor, Windsurf, Aider, Devin,
  OpenHands, Amazon Q, GitHub Copilot, Gemini, Claude, Junie…

🖥️ DOS client (client/)

• serial.bas: byte-by-byte reads with CR/LF trimming, reliable END
  detection, and better COM1 error handling.
• doscode.bas: byte-by-byte PROMPT send with explicit CRLF, improved
  status bar, and a sensible default model.
• parser.bas: support for inline <RUN>...</RUN>, confirmation prompt
  before execution, and TurnDone bridges that return control to the user
  after RUN.
• files.bas / ui.bas: cleanup and QB4.5 compatibility improvements.
• BUILD.BAT, RUN.BAT, DOSCODE.MAK: build and CRLF adjustments.

🐍 Python proxy (proxy/)

• llm.py: valid default model names for the different backends and a fix
  for Claude's authentication header.
• server.py: LLM line logging to stderr to help debug the stream.

🧰 Scripts and tooling (scripts/)

• scripts/monitor_serial.sh: socat -v tap that bridges
  TCP-LISTEN:2323 ↔ /tmp/pty_proxy and prints every byte in each
  direction, labelled [proxy->dos] / [dos->proxy], with per-direction
  log files.
• scripts/link_dosbox_project.sh: creates symlinks from the DOSBox-mounted
  directory back to client/, avoiding manual copies while editing.

📚 Documentation

• docs/build.md: validated setup using DOSBox nullmodem + socat
  PTY/TCP, plus a new section on the proxy's environment variables
  (API keys).
• docs/scripts.md (new): full guide for monitor_serial.sh and
  link_dosbox_project.sh, including the recommended DOSBox workflow.
• AGENTS.md: explicit rules for MS-DOS files (ASCII, CRLF, Ctrl+Z
  EOF, avoiding CONST / COMMON SHARED / ON ERROR GOTO).
• Bridges to several agents/IDEs: .cursorrules, .cursor/rules/,
  .windsurfrules, .openhands/microagents/, .amazonq/rules,
  .github/copilot-instructions.md, CLAUDE.md, GEMINI.md, DEVIN.md,
  CONVENTIONS.md, .junie/guidelines.md.
• .gitattributes: line-ending normalization (CRLF for DOS client files,
  LF for everything else).

✅ What works end-to-end in 0.1.0

• DOSBox boots the DOS client, opens COM1 against the PTY exposed by
  socat, sends PROMPT to the proxy, and receives streamed LINE ...
  responses until END.
• The user can confirm or cancel RUN actions before they execute.
• After a RUN, control always returns to the user prompt.

🛣️ Next milestones (not included in this release)

• Richer chat history and diff navigation.
• Undo state.
• File browser navigation.
• Automated application of multi-line <WRITE> blocks.

📦 Main changes (19 commits)

• fix(build): CRLF fixes and COM1 error handling.
• fix(client): QB4.5 compatibility, byte-by-byte reads, PROMPT with
  CRLF, reliable END detection, control return after RUN.
• feat(client): RUN confirmation and inline <RUN>...</RUN> support.
• feat(proxy): LLM line logging to stderr.
• fix(proxy): valid default models and Claude auth header fix.
• feat(scripts) + docs(scripts): monitor_serial.sh,
  link_dosbox_project.sh and their documentation.
• docs(build): validated socat PTY+TCP / DOSBox nullmodem setup and
  guide to proxy environment variables.
• docs(agents): rules for MS-DOS files and bridges for Cursor, Windsurf,
  Aider, Devin, OpenHands, Amazon Q and others.

🔧 Requirements

• DOS: QuickBasic 4.5 (BC.EXE, LINK.EXE) — see docs/build.md.
• Host: Python 3 with proxy/requirements.txt, socat for the PTY↔TCP
  bridge, and (optionally) DOSBox / DOSBox Staging.

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Full changelog: 0.0.0...0.1.0

Initial commit

DOSCODE 0.0.0 — Initial release 🕹️

First public snapshot of DOSCODE, a retro AI coding agent for real DOS
machines (MS-DOS, FreeDOS, DOSBox, 8086/286/386/486/Pentium-era hardware) that
talks to modern LLMs through a serial cable and a Python proxy.

Architecture:
MS-DOS client ⇄ plain-text serial ⇄ Python proxy ⇄ HTTPS ⇄ LLM provider

✨ Highlights

• Retro 80×25 text UI (SCREEN 0, CP437 boxes, ANSI-era colors).
• Plain-text serial protocol between the DOS client and the modern proxy — no
  TLS, no heavy JSON on the DOS side.
• Python 3 proxy with support for multiple LLM providers and progressive
  line-by-line streaming back to DOS.

🖥️ DOS client (client/)

Written in QuickBasic 4.5-compatible BASIC.

• TUI with fixed input line at the bottom and streamed chat area above.
• Serial I/O over COM1 / COM2 (serial.bas).
• Local commands: /read, /run, /model, /clear, /help, /exit.
• File read/write helpers (files.bas).
• Parser hooks for <READ>, <WRITE> and <RUN> tool actions (parser.bas).
• Confirmation prompt before executing any RUN action.
• Build helpers: BUILD.BAT, RUN.BAT.

🐍 Python proxy (proxy/)

• Serial transport via pyserial, plus stdio mode for local development.
• Plain-text line protocol (protocol.py) matching the DOS client.
• LLM backends (llm.py):
  • OpenAI-compatible chat completions
  • Claude Messages API
  • OpenRouter
  • Ollama
• Progressive LINE ... streaming to the DOS side.
• Launch helpers: run_proxy.sh, RUN_PROXY.BAT, requirements.txt.

📚 Documentation

• README.md — project overview, architecture and MVP scope.
• docs/build.md — QuickBasic 4.5 build notes and DOSBox setup.
• docs/protocol.md — serial wire protocol reference.
• AGENTS.md — contribution rules for AI agents working on the repo.
• LICENSE — project license.

✅ MVP scope covered in 0.0.0

• Opens the DOS TUI and draws the retro 80×25 frame.
• Connects to COM1 and sends prompts to the proxy.
• Receives streamed LINE ... responses and renders them progressively.
• Supports the full set of local slash commands listed above.
• Includes tool-action parser hooks with confirmation for RUN.

🛣️ Next milestones (not in this release)

• Richer chat history and diff navigation.
• Undo state.
• File browser navigation.
• Fully automated multi-line <WRITE> application.

📦 Contents

Initial commit 85e9acd — 19 files, ~1369 lines:

• client/: doscode.bas, ui.bas, serial.bas, parser.bas, files.bas,
  BUILD.BAT, RUN.BAT
• proxy/: server.py, llm.py, protocol.py, requirements.txt,
  run_proxy.sh, RUN_PROXY.BAT
• docs/: build.md, protocol.md
• Root: README.md, AGENTS.md, LICENSE, .gitignore

🔧 Requirements

• DOS side: QuickBasic 4.5 tools (BC.EXE, LINK.EXE) — not bundled.
  See docs/build.md.
• Modern side: Python 3 with the dependencies listed in
  proxy/requirements.txt.

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Full changelog: initial commit (85e9acd) — there is no previous tag to
compare against.