DOSBox Staging is a free, open-source DOS emulator for Windows, macOS and Linux. The DOSBox Staging team maintains this independent continuation of DOSBox. It runs DOS games and applications through its own DOS environment and emulates the IBM-compatible hardware those programs use.
Turning folders into DOS drives
Games access drive letters inside DOSBox Staging, so host folders and disk images first need mappings to those drives. Automounting uses lowercase drive-letter subfolders inside a drives folder: c becomes C:, for example. It also recognizes floppy and CD-ROM images and assigns the corresponding drive type.
The MOUNT command maps folders or images manually. Multiple images can share a drive letter, with a hotkey cycling between disks during play. Overlay mounts write changed files into a separate folder while retaining the original drive data.
Settings for each game
DOSBox Staging reads plain text configuration files with sections and setting values. Its primary file holds global preferences; a local dosbox.conf in the working directory overrides them for that game. Additional configuration files and individual command-line settings can override those values again.
The autoexec section runs DOS commands in order at startup. It can change drives, launch an executable and exit after the program finishes.
Controlling the virtual processor
The emulator implements a generic x86 processor with configurable speed. Separate cycle settings control real-mode and protected-mode programs, and hotkeys adjust the rate during play. Speed-sensitive games can behave incorrectly when the emulated processor runs too fast.
Automatic core selection uses an interpreter for real-mode programs and a dynamic recompiler for protected-mode programs. Optional throttling reduces cycles when the host cannot keep up. Memory settings separately control available RAM and DOS extended, expanded and upper-memory services.
From video hardware to display
DOSBox Staging separates graphics hardware emulation from image presentation. The machine setting chooses the video adapter and therefore the modes a DOS program can use. Choices cover Hercules, CGA, EGA, VGA and SVGA hardware. Voodoo emulation also handles hardware-level rendering for DOS games that support Glide.
Rendering settings then process the resulting picture. Adaptive CRT shaders follow the game’s video standard and available viewport; a sharp mode displays pixels without CRT effects. Aspect correction, scaling and viewport controls determine the image’s shape and placement. Colour adjustments change brightness, contrast, gamma and saturation.
Sound devices behind the soundtrack
The emulator provides sound devices including the PC speaker, AdLib, Sound Blaster and Gravis UltraSound. MIDI settings choose how the game’s musical instructions become sound:
| Playback choice | Sound source |
|---|---|
| Roland MT-32 | Emulates the sound module using ROM data you supply |
| Roland Sound Canvas | Emulates the SC-55 through the Nuked SC55 plugin and ROM data you supply |
| FluidSynth | Generates General MIDI audio from a SoundFont file |
DOSBox Staging can instead send MIDI messages to a host MIDI port for an external synthesizer. Its mixer combines internal sound-device channels into stereo output. Each channel has independent volume, panning, reverb, chorus and crossfeed controls, which the MIXER command changes from the DOS prompt.
Rebinding physical controls
The key mapper connects keyboard keys, mouse buttons and joystick controls to emulated input events. You select an event on its virtual layout, remove an existing binding or add a physical control. An event can accept several bindings, including modifier combinations.
DOSBox Staging saves these choices in a mapper file. A custom mapper path lets each game use its own control arrangement.
Capturing the emulator’s output
Screenshot controls distinguish raw framebuffer pixels, an upscaled image with aspect correction, and the final picture after shader processing. A default-format setting can request several image types from one capture action.
Video recording writes lossless ZMBV video into AVI files without CRT shaders. Separate shortcuts start and stop audio or MIDI recording. A capture-directory setting chooses where DOSBox Staging writes the files.
Connecting DOS programs
IPX emulation carries a game’s network packets over UDP/IP. One player starts an IPXNET server, and others connect to its address. Serial emulation also supports modem and direct null-modem links between emulator instances over a network.
For DOS TCP/IP applications, DOSBox Staging emulates an NE2000-compatible network card. The guest needs a packet driver and networking software. Port-forwarding settings map incoming host ports to services inside DOS.
Inspecting emulated memory
An optional HTTP API lets external tools read CPU registers and read or write emulated memory. Browser tools can use it for memory inspection and game modifications. The API starts disabled and listens locally by default.
