Megafortress part 1: Old Dog, new tricks

A guide to optimising a DOSBox install of Megafortress, the EB-52 Megafortress sim released by Three-Sixty Pacific, Inc. and Mindscape International Ltd. way back in 1991. Based on the Dale Brown military thriller, Flight of the Old Dog the EB-52 is an experimental, stealth enhanced Boeing B-52 Stratofortress.

Given the age of the sim and the recent optimisations that can be made to DOSBox Staging to enhance/optimise earlier DOS sims, as discussed in Tech refresh 2026: DOSBox best practice, Megafortress is ideal sim that may benefit from these fixes.

It's worth noting, that this isn't a really a flight sim in the normal sense, but an EB-52 systems simulator. You don't so much fly the aircraft, but fly the systems that operate the aircraft.

This guide will be using both the gog.com and retail releases.

Version & patch history

A brief version and patch history, due to the lack of clear information, some details are not confirmed. Products are listed in what is believed to be a rough chronological order.

Megafortress

The initial retail edition of Megafortress was released in 1991 on either 1 x 5.25" (1.2MB) High Density (HD) floppy disk or 1 x 3.5" (720KB) Double Density (DD) floppy disk. Developed by Artech Digital Entertainments, Inc. and published by Three-Sixty Pacific, Inc. and Mindscape International Ltd.

This can be considered a v1.0 release of Megafortress. The missions included with this version take place in the Red Flag Nevada training theater, Iraq theater and a mission based on Flight of the Old Dog taking place on the Kamchatka Peninsula.

Megafortress: Operation Sledgehammer

The first expansion pack, mission disk 1, Megafortress: Operation Sledgehammer was also released in 1991. It was released on either 1 x 5.25" (1.2MB) High Density (HD) floppy disk or 1 x 3.5" (720KB) Double Density (DD) floppy disk.

It is believed this mission disk also upgraded the version to v1.1, due to changes in the game executable file size and date, although this is unconfirmed as the version number is not listed in the game. It includes 25 new missions in the Iran and Libya theaters. This mission disk did not include the mission editor.

Mission editor

The mission editor may have been sold as a separate product in 1991, as it was not included in the Operation Sledgehammer expansion, but is referenced on the cover of the Megafortress Mega Pak with a retail price. Due to the rarity of this product, it may have only been sold as a mail order product through the developer or publisher.

Megafortress Mega Pak

The Megafortress Mega Pak was released in 1992 on 2 x 3.5" (720KB) Double Density (DD) floppy disk. It was a compilation release (believed to be v1.1) including:

• Megafortress

• Megafortress: Operation Sledgehammer

• Mission editor

Due to the floppy disk distribution and hard disk installer, this install method is compatible with the Operation SkyMaster expansion.

Megafortress: Operation SkyMaster

The second and final expansion pack, mission disk 2, Megafortress: Operation SkyMaster was also released in 1992. It was distributed on 1 x 3.5" (720KB) Double Density (DD) floppy disk.

This mission disk also upgraded the version to v1.2, with the version number listed in the intro. It includes 21 new missions in the Philippines and Korean peninsula theaters. This mission disk did not include the mission editor.

Megafortress Update patch

The Megafortress Update patch is believed to be a cumulative bug fix patch updating any previous version of Megafortress or Megafortress & Operation Sledgehammer to version 1.2. This is based on the creation date of the patch (Feb 1992) and size of the game executable as the patch has no release notes and after patching, the version is not displayed during the intro.

This patch is available from the Internet Archive.

Megafortress Mega Pak (Action Replay/Sixteen re-release)

The Megafortress Mega Pak was re-released by Digital Integration under the Action Replay/Sixteen budget label in 1996 on a single CD-ROM. This release is designed to save hard disk space by running from the CD-ROM, with only the hi-scores and roster saved to hard disk. This release is also pre-patched to version 1.2.

The default install is not compatible with the Operation SkyMaster expansion pack. Instead the contents of the CD must be manually copied to a hard disk before running the Operation SkyMaster installer.

Megafortress Collection

The Megafortress Collection is digital release available on gog.com and Steam platforms. It consists of:

• Megafortress (believed to be unpatched v1.0).

• Megafortress: Operation Sledgehammer (Action Sixteen CD release with Megafortress missions, v1.2).

• Megafortress: Operation SkyMaster (Action Sixteen CD release with Megafortress & Operation Sledgehammer missions and Operation SkyMaster expansion added, v1.2).

• Mission editor (using the Megafortress: Operation SkyMaster folder allowing all missions across all theaters to be edited).

The game, mission editor and all expansions use a DOSBox SVN build. It is bundled with a modern launcher app allowing some minimal DOSBox changes, access to the Megafortress documentation and a selection of the products described above.

Strategy

The first part of this guide covers a general DOSBox Staging config suitable for both retail and digital editions.

The strategy for the digital edition replaces DOSBox SVN with DOSBox Staging (in the launcher app) allowing the use of DOSBox Staging settings to optimise earlier sims like Megafortress. Digital edition specific DOSBox Staging config settings are covered. Additional advice on running the game is also provided.

The strategy for retails editions covers recommended installation and patching strategies. Specific DOSBox Staging config settings for the retail editions are covered.

FInally additional documentation applicable to both retail and digital editions is covered.

HOTAS config

As Megafortress doesn't support a joystick, there is no HOTAS config required. This sim concentrates on the EB-52 systems rather than flying.

Mouse is strongly recommended while the keyboard flight controls work well with this sim.

General DOSBox Staging config

This general DOSBox Staging config supplies all settings except those of the [autoexec] section which depend on the edition being used. This guide assumes the latest version of DOSBox Staging which is v0.82.2 at time of writing.

[sdl]
host_rate           = sdi
vsync               = off
presentation_mode   = cfr

[dosbox]
dos_rate             = host

[cpu]
core                 = simple
cputype              = 386
cpu_cycles           = 6000
cycleup              = 100
cycledown            = 100

[voodoo]
voodoo               = false

[mixer]
reverb               = small
chorus               = light

[joystick]
joysticktype         = disabled

[autoexec]
# Covered later

The [sdl] and [dosbox] settings have been optimized for earlier DOS games, with constant frame and refresh rates as described in the article, Tech refresh 2026: DOSBox best practice.

The [cpu] settings use the simple core as it provides slightly better compatibility with older games. The cputype is set to 386 for this early sim with the cpucycles set to 6000, comparable with a 386DX 33Mhz machine. This provides smooth performance without the sim running too quickly. The cycleup/cycledown settings are appropriate for lower cycles.

Voodoo emulation is not required and is disabled.

The mixer settings are a personal preference but these settings also seem appropriate for this early sim.

The joystick is disabled as Megafortress does not support a joystick (see HOTAS config).

The [autoexec] section is specific to the edition (retail or digital) and is discussed later.

Digital edition

The digital edition is also known as the Megafortress Collection, described earlier.

Important Note: Once you are using DOSBox Staging you should not validate/verify the installation with the Steam/gog.com client as this will overwrite the changes below.

The digital edition launcher

Installation

Installation should be performed using the appropriate platform client, so either the Steam client, gog.com Galaxy client or gog.com offline installer.

Running

When running this digital edition, it is recommended to always run the game from the Operation Skymaster expansion pack. It may seem strange to do so, but this option provides:

• A fully patched v1.2 game.

• All missions including, Megafortress, Operation Sledgehammer and Operation SkyMaster missions (a complete mission set).

• The mission editor uses the Operation Skymaster DOSBox folders to access any of the missions (except the Flight of the Old Dog mission), so any edited missions must be played from this option.

This means any DOSBox config changes will only need to be applied to the Operation Skymaster and mission editor configs.

Installing DOSBox Staging

This section switches the DOSBox SVN build used in the launcher app to a modern DOSBox Staging build. The process is as follows:

• Open the Megafortress installation folder. This will depend on the installation folder of the Steam/Galaxy client or the destination folder selected when the gog.com offline installer was run. As an example my Megafortress installation folder is:

D:\Program Files (x86)\GOG Galaxy\Games\Megafortress

• Open the Emulators folder and rename the DOSBox folder to another name, e.g. DOSBox.old.

• Download the latest DOSBox Staging release from Releases. For this particular task Download DOSBox Staging 0.82.2 (x86_64, Portable ZIP) is preferred.

• Extract the contents of the zip archive into the Emulators folder. There should now be a new dosbox-staging-v0.82.2 folder present.

• Rename the dosbox-staging-v0.82.2 folder to DOSBox.

• In the Emulators folder there should be a DOSBox.old (or whatever name you chose) and a DOSBox folder.

The launcher app will now use DOSBox Staging instead of DOSBox SVN. As we have renamed the original DOSBox SVN folder to DOBox.old it can be restored if desired.

DOSBox config

The DOSBox configs used by the launcher app are suitable for a DOSBox SVN build but not for DOSBox Staging. In this section we replace the DOSBox config for Operation SkyMaster and the mission editor with a more suitable one.

• Open the Megafortress installation folder. This will depend on the installation folder of the Steam/Galaxy client or the destination folder selected when the gog.com offline installer was run. As an example my Megafortress installation folder is:

D:\Program Files (x86)\GOG Galaxy\Games\Megafortress

• Open the GameData folder, two of the files present should be:

  • Megafortress_SkyMaster.conf.

  • Megafortress_Editor.conf.

• Rename these files, e.g.

  • Megafortress_SkyMaster.conf.old.

  • Megafortress_Editor.conf.old.

• Recreate the Megafortress_SkyMaster.conf and Megafortress_Editor.conf, using your preferred text editor (e.g. Notepad).

• Add the general DOSBox Staging config settings to both files.

• Copy the [autoexec] section from Megafortress_SkyMaster.conf.old and add it to Megafortress_SkyMaster.conf, or use the following lines listed below for convenience:

[autoexec]
@ECHO off
mount C C\Mega_SkyMaster
C:
SET PATH=Z:\;C:\tools;
@call mega
exit

• Copy the [autoexec] section from Megafortress_Editor.conf.old and add it to Megafortress_Editor.conf, or use the following lines listed below for convenience:

[autoexec]
@ECHO off
mount C C\Mega_SkyMaster
C:
SET PATH=Z:\;C:\tools;
@call editmsn
exit

The launcher app will now use DOSBox Staging with an appropriate config when running the Operation SkyMaster or mission editor options. As the original files have been renamed, they can be restored if desired.

This completes the digital edition setup, it is recommended to continue onto Documentation.

Retail edition

The retail edition covers all the non-digital releases of Megafortress, including Megafortress, Operation Sledgehammer, Operation Skymaster and the Megafortress Mega Pak.

Retail media

This guide assumes any physical media will be ripped to an image files to reduce wear and tear on media and drives.

Floppy disks can be ripped to a .img image, compatible with DOSBox. Alternatively the contents of the floppy disk can be copied to a folder if preferred. Megafortress floppy disk installation media does not contain copy protection.

The Megafortress Mega Pak cd can be ripped to a data only .iso format as there is no cd audio on the disc.

Game management

I recommend using my DOSBox game management strategy. Due to the different releases some folders are optional, depending on release:

• fdd - to store any floppy disk images or floppy disk contents (for floppy disk releases).

• cd - to store any cd images (for cd releases).

• hdd - the DOSBox Staging hard disk folder.

• conf - to store the DOSBox Staging configuration file.

• docs - to store any useful documents, manuals, etc.

• patch - to store a copy of recommended patches.

DOSBox config

The following are examples of imgmount commands used to mount floppy disk images in the [autoexec] section:

[autoexec]
# Hard disk
mount c "D:\Games\DOS\Megafortress\hdd"

# Megafortress/Sledgehammer/SkyMaster disk images
# imgmount a "D:\Games\DOS\Megafortress\fdd\mega.img" -t floppy
# imgmount a "D:\Games\DOS\Megafortress\fdd\sledge.img" -t floppy
# imgmount a "D:\Games\DOS\Megafortress\fdd\sky.img" -t floppy

# All Megafortress Mega Pak disk images (Alt-F4 to switch images)
# imgmount a "D:\Games\DOS\Megafortress\fdd\megapak1.img", "D:\Games\DOS\Megafortress\fdd\megapak2.img" -t floppy

# All disk images, using wildcard (Alt-F4 to switch images)
# imgmount a "D:\Games\DOS\Megafortress\fdd\*.img" -t floppy

The following are examples of mount commands used to mount folders holding the contents of floppy disk installer in the [autoexec] section:

[autoexec]
# Hard disk
mount c "D:\Games\DOS\Megafortress\hdd"

# Megafortress/Sledgehammer/SkyMaster disk folders
# mount a "D:\Games\DOS\Megafortress\fdd\mega" -t floppy
# mount a "D:\Games\DOS\Megafortress\fdd\sledge" -t floppy
# mount a "D:\Games\DOS\Megafortress\fdd\sky" -t floppy

# All Megafortress Mega Pak disk contents copied to same folder
# mount a "D:\Games\DOS\Megafortress\fdd\megapak" -t floppy

The following is an example of an imgmount command used to mount a Megafortress Mega Pak cd image in the [autoexec] section:

[autoexec]
# Hard disk
mount c "D:\Games\DOS\Megafortress\hdd"

# CD image
imgmount d "D:\Games\DOS\Megafortress\cd\megapak.iso" -t cdrom

The following is an example of commands to run the game once installation is complete:

[autoexec]
@echo off

# Hard disk
mount c "D:\Games\DOS\Megafortress\hdd"
c:

# Floppy release
# cd mega
# mega
# exit

# CD release
# call mega.bat
# exit

Installation & patching

All retail installation should take place in DOSBox Staging. The patch is distributed in .zip format and can be unzipped in Windows and the contents copied to a DOSBox hard disk folder, but the patch must be applied in DOSBox Staging.

Floppy disk/patch installation

The floppy disk installer used for the base game, expansions and patch is remarkably consistent. The installer is run with by calling install.com, the below screenshots show the process.

Installation questions

Installing

Manual CD installation

A manual CD installation is required if the Operation SkyMaster expansion will be installed afterwards.

• To install manually, the entire contents of the CD should be copied to the DOSBox Staging hard disk folder.

  
  

• Windows can be used to mount the cd image and copy the contents of the CD. Many may find this an easier than using DOSBox Staging.

• If the game management folders are used, the destination folder is the hdd folder (which becomes the C: drive in DOSBox Staging). As an example, my folder (in Windows) would be:

D:\Games\DOS\Megafortress\hdd

Installation & patching strategies

The following are the strategies for installing the retail releases with and without expansions, applying the patch if necessary.

Megafortress only:

• Install Megafortress.

• Apply Megafortress Update patch.

Megafortress & expansions:

• Install Megafortress.

• Install Operation Sledgehammer (if available).

• Install Operation SkyMaster (if available) or apply Megafortress Update patch (if SkyMaster missing).

Megafortress Mega Pak (floppy disk release) only:

• Install Megafortress Mega Pak.

• Apply Megafortress Update patch.

Megafortress Mega Pak (floppy disk release) & Skymaster expansion:

• Install Megafortress Mega Pak.

• Install Operation SkyMaster.

Megafortress Mega Pak (cd release) only:

• Install Megafortress Mega Pak (cd image must remain mounted to play, SkyMaster expansion cannot be installed later), or...

• Manual install of Megafortress Mega Pak (cd image not required, SkyMaster expansion can be installed later).

Megafortress Mega Pak (cd release) & Skymaster expansion:

• Manual install of Megafortress Mega Pak.

• Install Operation SkyMaster.

Documentation

The digital edition is missing what many consider crucial documents, the manuals for the expansion packs. Fortunately, Brian 'SpaceGameJunkie' Rubin has very kindly provided pdf versions of these documents and made them available on the Internet Archive!

• Megafortress: Operation Sledgehammer manual, pdf download.

  • [Internet Archive, Megafortress: Operation Sledgehammer Manual]

• Megafortress: Operation SkyMaster manual, pdf download.

  • [Internet Archive, Megafortress: Operation Sledgehammer Manual]

Intro with version number

Briefing

View from the pilot's seat

Finally...

Credit and thanks go to Brian 'SpaceGameJunkie' Rubin for providing the expansion pack manuals.

Good hunting!