VOGONS


First post, by EmanuelePulciDoria

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Motherboard: Dell Latitude 5501
Processor type and speed: Intel Corei5 9th Gen. 2496 MHz
Amount and type of RAM: 16GB
Video board w/ RAM amount and type: Nvidia GeForce MX150 (TDP 25 W), VRAM 2GB
Sound board: Realtek ALC3204
Operating system: Windows 10 Version 1809
Game name: 688 Attack Sub, 1989
Description of problem: Multiplayer mode not working neither with nullmodem connection nor with modem connection
Reproducibility of problem: always
Sound mode used: AD LIB SOUND BOARD
Video mode: VGA - MCGA, 256 colours
Version of emulator: DOSBox 0.74.3

Steps already attempted to solve the problem:
I am trying to test 688 Attack Sub with the multiplayer game mode without any success. I am testing the connection on 2 DOSBox instances on the same machine through
IP 127.0.0.1
There are 2 possible options: either through nullmodem or through a modem (dial) connection.
To learn how to use the 2 methods properly I tested them on Doom2 I am able to start the multiplayer mode in that game in both ways.
When I repeat the same process in 688 with the nullmodem connection I get Overrun errors whatever the rxdelay I use as reported as well in the following post:
Re: Null Modem Overrun Errors
On the other side I am not able to use the modem connection as it is because the game GUI gives you the possibility to dial only numbers (no dots) and no more than 11 so I cannot type 127.0.0.1 as 127000000001. This problem is reported as well in the following post:
688 Attack Sub and modem support or How to dial an IP address through an 11 (or less) digit number.
The solution in the latter is to create some sort of phonelist that translate 11 ciphers phone numbers in IP adresses recompiling DOSBox. This is not a solution at my level honestly.
However it looks like a phonelist can be setup in the config file according to the following post, exactly to get around the issue of GUIs that do not let you type proper IP address:
Directserial and Modem Guide
but h-a-l-9000's reply suggests this function is only present into a patch and probably not included in the latest DOSBox 0.74.3 version. I tried it anyway and it is not working. If you dial only the number 3 in order to dial the 3rd phone number in the list DOSBox just calls the IP address 3 (that clearly means nothing) and nothing happens.
I find hard to believe that since 2012 this problem has not been solved in some way. Is there a way to use the phonelist mentioned before? Is there any other way to get round the Overrun error for the nullmodem connection?
Some help here would be really appreciated.

Last edited by Stiletto on 2020-05-27, 20:29. Edited 1 time in total.

Reply 2 of 7, by EmanuelePulciDoria

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Eureka!!! I finally found the solution to this issue and it is not Dosbox but Dosbox-staging just recently released as a stable emulator. It is the only one I found that has the phone book feature strictly necessary to run the simulator through a modem connection. The phone book file needs to be located in the same place where the config file is. All the rest is explained in their website. The only note is that the person that replies to the call must be in auto-answer mode and not in manual answer otherwise the call starts and it gets stopped immediately as soon nothing replies on the other side.
Anyone that wants to know more info or play a match online is very welcome.

Reply 3 of 7, by _Rob

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EmanuelePulciDoria wrote on 2020-05-26, 21:47:

Eureka!!! I finally found the solution to this issue and it is not Dosbox but Dosbox-staging just recently released as a stable emulator. It is the only one I found that has the phone book feature strictly necessary to run the simulator through a modem connection. The phone book file needs to be located in the same place where the config file is. All the rest is explained in their website. The only note is that the person that replies to the call must be in auto-answer mode and not in manual answer otherwise the call starts and it gets stopped immediately as soon nothing replies on the other side.
Anyone that wants to know more info or play a match online is very welcome.

FYI, I ported the patch to DOSBox-X today, and it has been merged and will be in the next release which should be out in the next few days. So there are two DOSBox forks with the feature.

Reply 4 of 7, by EmanuelePulciDoria

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@Rob, I have just downloaded Dosbox-x and unfortunately 688 Attack Sub is not supported by this fork....the game does not start.

On the other end I have tried the modem connection with Dosbox-staging with another real friend, instead that on my local machine with 2 instances of Dosbox-staging open, and unfortunately the connection works and the game starts loading on both computers but for some reason it gets stuck at the very final step before entering the mission selected with the window "Game loading on other player's computer" never ending. Even 2-3 attempts to reconnect fail miserably.

At the moment I do not think any Dos emulator is actually able to run this multiplayer game, but I will keep trying with someone else with Dosbox-staging to see if the problem happens with everyone or only with someone.

Reply 5 of 7, by _Rob

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@EmanuelePulciDoria before running the game type "loadfix", and it should work.

As to the multiplayer issues, I suspect you will probably have the same issue, but give it a try.

Reply 6 of 7, by EmanuelePulciDoria

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Finally the last piece of the puzzle is solved! There are different DOS versions of 688 Attack Sub online. All the one that I have seen work fine in single player mode but only the one I initially downloaded works as well in multiplayer mode.
The one that works in modem connection has to have the details in the following files like this:
$ md5sum *.EXE
4552638ddf08042531ec3a23971e9459 CALLS.EXE
51bb0bbb9b85d33fefab88a69919a449 GAME.EXE
0b2f619ce7067f249416d2b060398e52 TITLE.EXE

This file could be found at Old-games.com under the 688 Attack Sub DOS page and it is the 599KB release and I attached it here as well.

Both Server and client must have this version in order for the modem connection to work.
I tried the modem connection under 127.0.0.1 both with dosbox-staging and DOSbox-X and it worked.
I tried the connection under the local network with DOSbox-X between a Windows 10 64bit and a Windows XP 32bit and it worked.
I tried as well the connection with dosbox-staging between a Windows 10 64bit and a MacOS Catalina and on the web using my external router IP address and it worked as well.
So there is finally a solution to this issue.
Regarding the nullmodem connection it looks like 688 Attack Sub uses the nullmodem cable in a different way compared to the one set up in DOSbox and as a consequence the nullmodem connection does not work in any of the emulators. A different code for the 688 nullmodem connection should be written in order for it to actually work.

Attachments

  • Filename
    688.zip
    File size
    599.16 KiB
    Downloads
    28 downloads
    File comment
    688 Attack Sub multiplayer mode supported
    File license
    CC-BY-4.0