Skip to content

DOS¶

The [dos] section controls the emulated DOS environment itself — version number, memory management, and regional settings.

The reported DOS version defaults to 5.0, which covers the vast majority of games from the entire DOS era. A handful of very late titles check for DOS 7.0, and some very early ones expect DOS 3.0, but these are edge cases you’ll likely never hit.

Memory management¶

The first IBM PCs only supported up to 640 KB of memory — the so-called “conventional memory” that DOS programs can access directly. As PCs gained more RAM, a patchwork of standards emerged to make the extra memory available:

  • XMS (Extended Memory) — the main pool of memory above 1 MB. This is what the memsize setting controls (16 MB by default). Nearly all games from the late DOS era use XMS.

  • EMS (Expanded Memory) — an older scheme that maps 64 KB pages of memory into the conventional memory area. Some early to mid-1990s games require EMS; a few older titles may actually malfunction if it’s enabled.

  • UMB (Upper Memory Blocks) — small pockets of memory between 640 KB and 1 MB, used to free up conventional memory by loading drivers and TSRs into them.

All three are enabled by default and you can safely ignore them. On the rare occasion a game misbehaves (usually an old title that chokes on EMS), disabling the offending memory type is a quick fix.

Regional settings¶

DOSBox Staging automatically detects your host operating system’s language and keyboard layout, so in most cases it just does the right thing out of the box. If you need to override the defaults — perhaps you’re running a German game on an English system, or you need a specific date format — a few settings let you fine-tune the regional behaviour.

The country setting controls DOS-level formatting conventions: date and time format, decimal separators, currency symbols, and so on. The keyboard_layout setting selects the DOS keyboard layout, determining which characters are produced by which keys. locale_period lets you specify the decimal separator regardless of the country setting.

To see what’s available on your system, start DOSBox Staging with the following command line arguments:

Note

Use the language setting in the [dosbox] section to set the language of DOSBox Staging’s own interface.

Configuration settings¶

You can set the DOS parameters in the [dos] configuration section.

Regional settings¶

country¶

Set DOS country code (auto by default). This affects country-specific information such as date, time, and decimal formats. If set to auto, it selects the country code reflecting the host OS settings.

Note

The list of country codes can be displayed using the --list-countries command-line argument.

keyboard_layout¶

Keyboard layout code (auto by default). Set to auto to guess the values from the host OS settings. The layout can be followed by the code page number, e.g., uk 850 selects a Western European screen font. After startup, use the KEYB command to manage keyboard layouts and code pages (run HELP KEYB for details).

Note

The list of supported keyboard layout codes can be displayed using the --list-layouts command-line argument (e.g., uk is the British English layout).

locale_period¶

Set locale epoch.

Possible values:

  • native default – Re-use current host OS settings, regardless of the country set; use modern data to fill in the gaps when the DOS locale system is too limited to follow the desktop settings.
  • historic – If data is available for the given country, mimic old DOS behaviour when displaying time, dates, or numbers.
  • modern – Follow current day practices for user experience more consistent with typical host systems.

Memory¶

ems¶

Enable EMS support. Enabled provides the best compatibility but certain applications may run better with other choices, or require EMS support to be disabled to work at all.

Possible values: on default, off

xms¶

Enable XMS memory support.

Possible values: on default, off

umb¶

Enable UMB memory support.

Possible values: on default, off

pcjr_memory_config¶

Set PCjr memory layout.

Possible values:

  • expanded default – 640 KB total memory with applications residing above 128 KB. Compatible with most games.
  • standard – 128 KB total memory with applications residing below 96 KB. Required for some older games (e.g., Jumpman, Troll).

Shell & version¶

ver¶
Set DOS version in MAJOR.MINOR format (5.0 by default). A single number is treated as the major version. Common settings are 3.3, 5.0,
expand_shell_variable¶

Enable expanding environment variables such as %PATH% in the DOS command shell. FreeDOS and MS-DOS 7.0+ COMMAND.COM support this behaviour.

Possible values:

  • auto default – Enabled if DOS version is 7.0 or above.
  • on – Enable expansion of environment variables.
  • off – Disable expansion of environment variables.
file_locking¶

Enable file locking via emulating SHARE.EXE. This is required for some Windows 3.1 applications to work properly. It generally does not cause problems for DOS games except in rare cases (e.g., Astral Blur demo). If you experience crashes related to file permissions, you can try disabling this.

Possible values:

  • auto default – Enable file locking only when Windows 3.1 is running.
  • on – Always enable file locking.
  • off – Always disable file locking.
setver_table_file¶
File containing the list of applications and assigned DOS versions, in a tab-separated format, used by SETVER.EXE as a persistent storage (empty by default).
shell_history_file¶
File containing persistent command line history (shell_history.txt by default). Setting it to empty disables persistent shell history.

6.22, and 7.1.