Memory Wrapper

Windows desktop wrapper around a legacy DOS accounting program (Memory Contab, contab.exe). It runs the DOS program inside DOSBox-X, captures its printer output, and turns each printed report into a modern PDF the user can preview and archive — all without the user ever touching DOSBox or a real printer.

Platform: Windows only. The app relies on Win32 APIs (ctypes.windll, os.startfile) and Windows system fonts.

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Scope & audience

This wrapper is purpose-built for the Memory DOS accounting suite (Memory Computación) — specifically its Contabilidad Central module (contab.exe), an old Turbo Pascal program. It is not a general-purpose DOS-to-PDF tool: the ESC/P parsing and the expected data layout are tailored to that program.

It targets organizations still running this legacy accounting system on modern Windows that need to turn its printed reports into PDFs — preview and archive — without a real printer or ever touching DOSBox. It is distributed as a single Windows installer that bundles everything (the wrapper, DOSBox-X, the DOS program and its data).

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How it works

┌────────────┐   prints    ┌─────────────┐   .PRN file   ┌──────────────┐
│ contab.exe │ ──────────► │  DOSBox-X   │ ────────────► │  PRNWatcher  │
│  (DOS)     │  (LPT1)     │ (emulator)  │  (on disk)    │  (watchdog)  │
└────────────┘             └─────────────┘               └──────┬───────┘
                                                                │ stable file
                                                                ▼
                              ┌──────────────┐   Line[]   ┌───────────┐
                              │ pdf_generator│ ◄───────── │ prn_parser│
                              │   (fpdf2)    │            │  (ESC/P)  │
                              └──────┬───────┘            └───────────┘
                                     │ temp .pdf
                                     ▼
                              ┌──────────────┐  "Save"   ~/Desktop/Memory Docs/
                              │ PreviewWindow│ ────────► <year>/<month>/Reporte dd-mm-yyyy.pdf
                              │   (PyQt6)    │
                              └──────────────┘

1. Launch — main.py starts DOSBox-X with legacy/dosbox-x.conf, which mounts the program directory and auto-runs contab.exe.
2. Capture — when the operator prints a report inside the DOS program, DOSBox writes a .PRN file (raw ESC/P printer stream) into legacy/program/.
3. Detect — PRNWatcher (watchdog) sees the new/changed .PRN, waits until it is fully written, and signals the UI thread.
4. Parse — report/parser.py decodes the ESC/P control codes (bold, double-width, condensed) into a list of Line objects made of styled Segments.
5. Render — report/generator.py lays the lines out into a landscape PDF using the Consolas monospaced font.
6. Preview & save — PreviewWindow renders the PDF (PyMuPDF) and lets the operator save it to Desktop/Memory Docs/<year>/<month>/.

When DOSBox-X is closed, the wrapper shuts down with it.

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Project layout

src/
  main.py             → entry point (python src/main.py)
  factory.py          → create_app(): composition root (builds settings, logging, wiring)
  settings.py         → centralized config (paths, fonts/sizes, quiet_period, logging)
  logger.py           → logging setup (rotating file + console)
  core/
    signals.py        → Qt signal bridge (watcher thread → UI thread)
    utils.py          → base-path resolution (dev vs PyInstaller-frozen)
  dosbox/
    launcher.py       → launches DOSBox-X and monitors its lifecycle
    watcher.py        → watchdog observer; debounced detection of a finished .PRN
  report/
    parser.py         → ESC/P byte stream → Line[] / Segment[] (style-aware)
    generator.py      → Line[] → landscape PDF (fpdf2)
  ui/
    controller.py     → one preview window per report; off-thread PDF worker
    preview_window.py → PDF preview with loading state, save-to-archive
    styles.py         → Qt stylesheet snippets

tests/                → pytest suite, mirrors the src/ layout

legacy/
  dosbox-x.conf       → DOSBox-X configuration (autoexec mounts + runs contab.exe)
  program/            → DOS program + real client data — NOT in this repo (gitignored)

installer/setup.iss   → Inno Setup script
MemoryWrapper.spec    → PyInstaller build spec
assets/               → application icon

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Requirements

• Windows 10/11
• Python 3.12 (>=3.12,<3.13)
• Poetry for dependency management
• DOSBox-X installed (the installer expects it under C:\DOSBox-X)
• Consolas font (consola.ttf, consolab.ttf) — ships with Windows

Python dependencies (see pyproject.toml): watchdog, pyqt6, fpdf2, pymupdf, pillow; dev: pyinstaller, pytest.

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Development

poetry install
poetry run python src/main.py   # full run; needs DOSBox-X + the DOS program (see note)
poetry run pytest               # run the test suite

Note: a full end-to-end run needs DOSBox-X reachable at dosbox/dosbox-x.exe (relative to the repo root) and the DOS program under legacy/program/ — neither is included in this repository. The parser, PDF generator, settings and watcher are covered by the test suite and run without DOSBox.

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Build & installer (Windows)

The deliverable the client installs is built in two steps, both on Windows.

Prerequisites

• Inno Setup installed.
• DOSBox-X present at C:\DOSBox-X (the installer bundles it from there).
• The DOS program and its current data under legacy/program/ (not included in this repo). The program reads each company from \CONT\<company>\ relative to the mounted drive, so the live data must sit under legacy/program/CONT/.

1. Build the executable (PyInstaller):

poetry install
poetry run pyinstaller MemoryWrapper.spec     # → dist/MemoryWrapper.exe

2. Build the installer (Inno Setup):

Open installer/setup.iss in the Inno Setup Compiler and build it (or run ISCC.exe on it). It bundles MemoryWrapper.exe, assets/, the DOS program + data under legacy/program/, the DOSBox-X config, and DOSBox-X itself. Output: installer/Output/MemoryWrapper_Installer.exe, which installs to C:\MemoryWrapper.

⚠️ The installer bundles legacy/program/ (including the accounting data) and overwrites it on install. Correct for a first install; before shipping an update, exclude the live data so a reinstall does not wipe the client's entries.

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Output

Saved reports land in:

%USERPROFILE%\Desktop\Memory Docs\<year>\<month-in-spanish>\Reporte <dd-mm-yyyy>.pdf

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Known limitations

• Windows-only by design.
• Font paths and the DOSBox-X source path are currently hardcoded.

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License

MIT — see LICENSE.