688 Attack Sub
688 Attack Sub is a multiplayer game.
Packed file is corrupt
If you receive the error "Packed file is corrupt" when starting the game, make sure you first run LOADFIX. LOADFIX is included with DOS 5.0 or later, and is also included with DOSBox.
The game has options for two-player gaming using either a serial null-modem, or a regular serial modem.
- To use the null-modem option a non-standard null-modem cable is required, that is documented in the games manual.
- The modem option does not appear to work in every version of the game. Additional clarity is needed, but some versions will disconnect immediately once a connection has been established.
|Use DOSBox-X|
When run in DOSBox-X, it is possible to use the serial modem emulation to setup a two-player game.
It is necessary to setup and start one game in "server" mode and the other in "client" mode.
On the "Mission Selection" screen, both players must select the same mission to play, and one player needs to select blue and the other red. Only missions with a lightning symbol next to them are supported for multi-player.
On the "Configuration Panel" screen, both players must ensure that "MODEM ON COM1:" is selected. Then the player with the Server config must select "AUTO-ANSWER" and wait for the client to connect.
The player with the client config must ensure that the "SET TELEPHONE NUMBER" is set to "1", and click "ORIGINATE"
Server Setup - DOSBox-X config
The person that will run in server mode needs to configure his DOSBox-X with the following settings:
[dosbox] title=688 Attack Sub - Server [cpu] core=normal [serial] serial1 = modem listenport:12345 rxdelay:50 [autoexec] mount c . c: loadfix /a 688.bat
Client Setup - DOSBox-X config
The person that will run in client mode needs to configure his DOSBox-X with the following settings:
[dosbox] title=688 Attack Sub - Client [cpu] core=normal [serial] serial1 = modem rxdelay:50 phonebookfile = phonebook.txt [autoexec] mount c . c: loadfix /a 688.bat
Client Setup - phonebook file
Please create a file named "phonebook.txt" with the following content:
Replace "localhost" in the above phonebook file example with the IP address or hostname of the player running the server config.
Configuration file(s) location
The game does not provide a means to save its config. The game will present the video and audio options each time the game is started.
However, there is a way to start the game directly with your preferred options. For instance if you always want to start the game with VGA (option 4) and Adlib (option 1), you can start the game like such:
Save game data location
|4K Ultra HD|
|Field of view (FOV)|
|Windowed||For DOSBox toggle with Alt+↵ Enter (see the glossary page for other workarounds).|
|Borderless fullscreen windowed||See the glossary page for potential workarounds.|
|Anisotropic filtering (AF)|
|Vertical sync (Vsync)|
|60 FPS||Depends on video mode|
|Keyboard and mouse||State||Notes|
|Remapping||For DOSBox use the DOSBox Mapper (see the glossary page for other workarounds).|
|Mouse sensitivity||For DOSBox set in the DOSBox configuration file.|
|Mouse input in menus|
|Mouse Y-axis inversion|
|Controller support||For DOSBox use the DOSBox Mapper (see the glossary page for other workarounds).|
|Separate volume controls|
|Mute on focus lost||For DOSBox change the
|Royalty free audio|
|Peer-to-peer||Using serial modem or null-modem|
|Self-hosting||Using serial modem or null-modem|
|DOS video modes||Hercules, CGA, Tandy, EGA, MCGA, VGA|
- No middleware information; you can to add it.
|Operating system (OS)||2.0||5.0|
|System memory (RAM)||384||640|
|Hard disk drive (HDD)|
|Video card (GPU)||CGA / Hercules||Tandy, EGA, MCGA, VGA|