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dosdoor

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What dosdoor is

dosdoor is a DOS emulator for running BBS door games on Linux and macOS. It is derived from dosemu 1.4.0, with subsystems removed to focus on text-based games and their BBS connections. The project describes it as a drop-in replacement for dosemu in PhotonBBS doorexec scripts. It supports virtual COM ports connected to standard input and output, UART emulation, BIOS serial services, and a FOSSIL driver. Terminal output supports ANSI and VT100. For BBS setup, dosdoor accepts formats including DORINFO1.DEF, DOOR.SYS, and SRDOOR; Barren Realms Elite uses its own setup utility. The README lists tested games including LORD, Barren Realms Elite, Operation: Overkill II, The Simpsons, and Darkness. Tested host builds cover Linux x86_64 and macOS on Apple Silicon and x86_64. On Linux x86_64, both the full interpreter and JIT compiler are listed as tested; macOS builds use the full interpreter. JIT is limited to x86_64. Each game needs game files, a launch batch file, and BBS drop files in a known location. The project identifies dosdoor as GPLv2, inherited from dosemu.

Who it suits

dosdoor suits BBS operators who want to run text-based DOS door games on Linux or macOS, particularly with PhotonBBS doorexec scripts. It is also a fit for users whose games work through the listed BBS drop files and terminal or serial interfaces.

What it does well

  • Free to use, with a GPLv2 license.
  • Works with PhotonBBS doorexec scripts as a dosemu replacement.
  • Supports DORINFO1.DEF, DOOR.SYS, and SRDOOR drop files.
  • Provides ANSI/VT100 output and virtual COM port support.
  • Lists tested builds for Linux x86_64 and two macOS architectures.

What to know first

  • Removes sound, graphics, mouse support, and networking.
  • Also excludes SCSI/CDROM, DMA, and joystick support.
  • JIT is limited to x86_64.
  • Each game requires files, a launch batch file, and BBS drop files.

Limits

dosdoor omits sound, graphics, mouse support, networking, SCSI and CDROM, DMA, joystick, and character sets beyond CP437. JIT is available only on x86_64.

Getting started

  1. Open the dosdoor GitHub project.
  2. On macOS, use the Homebrew installation method in the README.
  3. On Fedora or RHEL, download an RPM release or build from the spec file.
  4. Prepare the game files, a launch batch file, and BBS drop files in a known location.
  5. Configure a supported drop-file format; Barren Realms Elite uses its own setup utility.

Verdict

Choose dosdoor if you need a text-focused DOS emulator for BBS door games and your setup matches its supported host builds and drop-file formats. Look elsewhere if your games depend on sound, graphics, mouse input, networking, or other removed hardware features.

Questions

Is dosdoor free?

The listed pricing model is free, and the project identifies the software as GPLv2. No trial is listed.

Which platforms does it support?

The listed platforms are Linux and macOS. Tested builds include Linux x86_64 and macOS ARM64 and x86_64.

Which BBS drop files does it support?

Listed formats include DORINFO1.DEF, DOOR.SYS, and SRDOOR. Barren Realms Elite uses its own setup utility.

Does it support sound or graphics?

No. Sound and graphics are among the subsystems removed from dosdoor.

How can I install it?

The README gives a Homebrew method for macOS. Fedora and RHEL users can download an RPM release or build from the spec file.

Facts from dosdoor's own pages

Backward compatibility
The DOSEMU_HOGTHRESHOLD environment variable is accepted for compatibility, and the project says it has built-in idle detection. · github.com, 8 Oct 2026
Base
It is derived from dosemu 1.4.0, with sound, graphics, networking, and other subsystems removed. · github.com, 8 Oct 2026
BBS integration
dosdoor is described as a drop-in replacement for dosemu in PhotonBBS doorexec scripts. · github.com, 8 Oct 2026
Compatibility
It is derived from dosemu 1.4.0, with sound, graphics, networking, and other subsystems removed. · github.com, 7 Oct 2026
CPU modes
The default selects JIT on x86_64 and full software interpretation elsewhere; JIT is limited to x86_64. · github.com, 8 Oct 2026
Drop file formats
Supported formats listed include DORINFO1.DEF, DOOR.SYS, and SRDOOR. · github.com, 8 Oct 2026
Drop files
It works with standard BBS drop file formats including DORINFO1.DEF and DOOR.SYS, and notes that BRE uses its own setup utility. · github.com, 7 Oct 2026
Game setup
Each game requires game files, a launch batch file, and BBS drop files in a known location. · github.com, 8 Oct 2026
Game support
The README lists tested games including LORD, Barren Realms Elite, Operation: Overkill II, The Simpsons, and Darkness. · github.com, 7 Oct 2026
Installation
The README gives Homebrew installation for macOS and RPM download or spec-file build instructions for Fedora/RHEL. · github.com, 8 Oct 2026
License
The project states it is licensed under GPLv2, inherited from dosemu. · github.com, 8 Oct 2026
Linux support
Linux x86_64 is listed as tested with both the full interpreter and JIT compiler. · github.com, 8 Oct 2026
macOS support
macOS ARM64 (Apple Silicon) and macOS x86_64 are listed as tested with the full interpreter. · github.com, 8 Oct 2026
Maker location
The GitHub profile lists Florida. · github.com, 7 Oct 2026
Notable limits
The project removes sound, graphics, mouse support, networking, SCSI and CDROM, DMA, joystick, and non-CP437 character sets. · github.com, 7 Oct 2026
Pricing
The repository page provides no product pricing information. · github.com, 7 Oct 2026
Purpose
dosdoor is a stripped-down, cross-platform DOS emulator built to run BBS door games. · github.com, 8 Oct 2026
Serial and terminal features
It supports virtual COM ports mapped to stdin and stdout, UART emulation, BIOS serial services, a FOSSIL driver, and ANSI/VT100 terminal output. · github.com, 7 Oct 2026
Serial I/O
It provides virtual COM ports mapped to stdin/stdout, UART emulation, BIOS serial services, and a FOSSIL driver. · github.com, 8 Oct 2026
Supported systems
The README lists tested builds for Linux x86_64 and macOS on Apple Silicon and x86_64. · github.com, 7 Oct 2026
Terminal
Text terminal output supports ANSI/VT100 through the slang library. · github.com, 8 Oct 2026
Tested games
The README lists LORD, Barren Realms Elite, Operation: Overkill II, The Simpsons, and Darkness as tested door games. · github.com, 8 Oct 2026

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