MechWarrior 2: Mercenaries FAQ

Last revised: 20 Jan 1997
This document answers many Frequently Asked Questions about MechWarrior 2: Mercenaries.
The original copy of this document is located at .

Table of Contents

Other sources of info

Latest Version

The current version of Mercenaries is version 1.06.

Version 1.06

Version 1.06 is primarily for people developing custom missions, and makes testing new missions much easier. It only affects the DOS version; it does not change the Windows version. The 1.06 patch will upgrade your copy of Mercenaries 1.05 (English) to version 1.06, which includes the following improvements: You can tell if you have version 1.06 by looking at the date of MW2.EXE, MW2SHELL.EXE, and NETSHELL.EXE. They are dated November 20th, 1996 for version 1.06. If you have earlier versions, you need 1.06.

MercNet 1.06 is fully compatible with MercNet 1.05. People with 1.05 can play against people who have 1.06 without noticing any difference.

The patch is downloadable for free at
And is mirrored at The Eagles Ftp site
Note:The 1.06 patch requires version 1.05. If you have version 1.00, you need to install the 1.05 patch before installing 1.06.

Version 1.05

Version 1.05 includes changes in the following areas of version 1.00: You can tell if you have version 1.00 by looking for the file SHELLFIX.MW2 in your Mercs directory. If you see MERCS.EXE but not SHELLFIX.MW2, you have version 1.00, and need the patch.

MercNet 1.05 uses a different multiplayer protocol than MercNet 1.00. People with 1.00 can't see people who have 1.05; 1.00 and 1.05 are separate universes.

The patch is downloadable for free at
And is mirrored at The Eagles Ftp site

Installing Mercenaries

How do I install in DOS? I keep getting "Bad Command or Filename."

You must be in the CD's \DOS\ directory to run INSTALL.EXE.

What are the system requirements?

For modem/internet play: Here are some recommended performance guidelines: (The options can be adjusted by pressing the ESC key while in a mission or in the shell, and selecting "Combat Variables.")

Graphics Card Support

What's the story on 3-D card support for Mercenaries?

We haven't announced 3-D card versions of Mercenaries yet. It's fair to assume we're working on something, but for now stick to the standard version. Writing a well optimized Direct-3D version or a version tailored for a particular 3-D card would take some time.


I have a 486DX2/66Mhz, and Mercs runs too slow and choppy!

On a 486/66, you have to turn off the extra display options, and choose 320x200 resolution. In the shell (before launching), you can do this by pressing ESC, then Combat Variables, then turn all the DETAIL settings to OFF or LOW, and choose 320x200 for RESOLUTION. The most important display option to turn off is Terrain Textures. (You can also set all but the resolution in the sim after launching.) Also, once in the sim, press F4 twice to turn off the enemy damage display.

I have a great graphics card, but the movies in Win95 Mercs still run slow!

If your display is set for 24-bit color, the Mercs shell may run slowly, but the Mercs sim will run just fine. If the movies in the shell are too jerky for you, switch your graphics card to 8 bit color. This is done by right-clicking the desktop background, choosing Properties / Settings, and setting Color Palette to 256 colors.


How do I get sound in DOS Mercs?

If you used the Win95 setup to install Mercs, you'll need to run SETSOUND by hand to set up sound in DOS Mercs. You can use SETSOUND to test whether the sound is working, too.

Why is there no sound in MercNet?

There is sound in the MercNet Sim once you launch the mission, but there is no sound while setting up missions in the MercNet Shell. (The Shell is where you set up games; the Sim is when you're driving a 'Mech around.)


I get divide overflows with DOS Mercs when I use my Sidewinder in digital mode!

Set your Sidewinder to use analog mode- this should get rid of the divide overflows. To do this, set the switch on the base of the joystick to the "one dot" position, and set up Mercs for "CH Pro" joystick.

I have trouble calibrating my Thrustmaster F16 FLCS!

One user reports:
I found the problem for my calibration with my TH F16 FLCS.
If I set up the trigger to digital instead of analogue,
I can calibrate normally in Mercs.
We have not confirmed the problem or the fix.

How come there's no way to reverse the direction of my rudder pedals?

See the discussion of Cockpit Configuration below.

The 'Mech Lab

I'm having problems adding Ferro-Fibrous or Endo-Steel to a 'Mech.

You probably need to install the 1.05 patch!

How come double heat sinks take up 3 critical slots instead of 2?

According to the Battletech Compendium, Inner Sphere double heat sinks take up 3 critical slots; Clan double heat sinks take up 2 critical slots.


I have 8 Meg of RAM, and am playing DOS Mercs. Why does the game lock up after a few minutes?

Here are a few tips that should help resolve the problem:
  1. Improperly configured memory managers can cause crashes. If you use EMM386 or a similar memory manager, be sure to follow any instructions in your graphics card's manual about excluding ranges of memory from use by memory managers! Or try disabling your memory manager entirely by editing CONFIG.SYS and inserting the word REM in front of any line containing EMM386.EXE, HIMEM.SYS, or any other memory manager. You may want to make a boot floppy and edit the boot floppy's CONFIG.SYS rather than editing your hard disk's CONFIG.SYS. In any case, make a copy of CONFIG.SYS before changing it, so you can get back the original if something goes wrong.
  2. Using the Sidewinder joystick in digital mode with DOS Mercs causes trouble. If you have a Sidewinder, be sure to set the switch on the base of the joystick to the "one dot" position, and set up Mercs for "CH Pro" joystick. (If you don't, you'll probably experience "CAUSEWAY Errors" due to divide overflows every other game or so.)
  3. Some old mouse drivers cause trouble. If you have followed the above steps, are still having trouble, and are using an older mouse driver or a non-microsoft mouse driver, try loading a version 9.xx Microsoft mouse driver instead of your current one.
  4. If all else fails, try turning off the sound or music - this sometimes keeps the crash from happening.

When I get into the Merc95 sim, it says "Error 53: CD Not Mounted," but MercDOS sim works fine.

One person reports "It was because I had the MS powertools flexi CD loaded. When I exited flexi CD (closed it from the sys tray) the game ran fine."

When I try to run with a multiple-CD-ROM-turntable drive, it takes forever to sense the drive, or exits with "Error 53: CD Not Mounted."

You probably need the 1.05 patch!

When I get into the DOS sim, it sits on the neurohelmet screen forever, with that little EKG animation going, and I can't get into the game!

This seems to be a problem reading the CD-ROM drive. People report that ejecting and reinserting the CD fixes the problem and lets you continue the game.

A few missions into the game, it starts to lock up or page fault!

This happened in the 1.0 version of the game; installing the Mercs 1.05 patch should help.

After a crash in DOS Mercs, I often see the message "Causeway Error". What's that?

That means that a divide overflow, general protection fault, or other serious error occurred. Usually, a special crash log, CW.ERR, is written to disk. You can help us track down problems by sending a copy of CW.ERR along with a description of the crash and a description of your system, including joystick, to

Often, these are caused by using the Sidewinder in digital mode.

I have an Ensoniq Vivo sound card, and Mercnet DOS reboots my computer when I exit the sim!

There is a bug in the driver for the Vivo sound card. You might be able to download an update from Ensoniq. You should also be able to avoid the bug by not loading the Vivo's DOS drivers.

Controls and Keystrokes

Hey! Where'd Image Enhancement go? 'w' doesn't work anymore.

You can get it back by adding the line
ENHANCED_VISION                 w
into GAMEKEY.MAP. It was taken out partly because the Inner Sphere doesn't have image enhancement technology, and so the feature wasn't quite finished - lasers don't show up when it's on.

The custom config screen can't flip the direction of torso twist, nor will it let me use CTRL, ALT, or SHIFT!

The Cockpit Configuration in Mercenaries version 1.0 was missing the columns that let you flip the direction of each control. This was fixed in Mercenaries version 1.05.


I'm using Mercs 1.0, my friend is using Mercs 1.05 or 1.06, and we can't see each other in the Pilot's Lounge!

Both players need to be using compatible versions of Mercenaries! If you can't see each other, one of you probably has version 1.00, and needs to upgrade to version 1.05. (1.05 and 1.06, on the other hand, are interchangable as far as multiplayer interoperability goes.)

Sometimes I get a "Zero Mek" error while in the Ready Room. What's that?

There is a problem in how custom 'Mechs are sent between players; occasionally when someone chooses a custom 'Mech, other players are kicked out with a "Zero Mek" error. The only workaround at present is to host a game that does not allow custom 'Mechs; we will have a fix for this in a future release.

How do I start a password-protected game?

Type ALT H instead of clicking on the HOST button. For a list of other keyboard commands available during chat, type /help in the chat window of the Pilot's Lounge.

MercNet and the Internet

How do I play MercNet over the Internet?

The file INTERNET.TXT has step by step instructions for how to dial up your ISP using MERCPPP.

Why do I have to use MERCPPP? Why can't I use the Win95 TCP/IP stack?

MercNet is currently a DOS application. We are investigating creating a native Win95 version of MercNet which will be compatible with the Win95 TCP/IP stack.

I use SLiRP or TIA to access my Internet account. Why can't I see anyone in the Pilot's Lounge?

MercNet requires true PPP. SLiRP and TIA are PPP emulators that don't support features needed by the MercNet Internet driver. You may be able to get around the problem by using a 3rd party IPX emulator such as Kali, but we have not confirmed this.

When I run MERCPPP and enter in my ISP's phone #, etc., it takes all my inputs and seems to "save to net.cfg" just fine, but I never get the main menu afterwards. It only gives me the "current" selection again.

The first time you go through MERCPPP.BAT and enter in your COM port, you *must save and exit* before you can see the main menu. That's right - hit ESC again after saving and say YES when it asks if you want to leave. MERCPPP will then take you to the main menu. (The main menu won't show up until PPP is loaded, and it can't load PPP until you tell it what COM port you have and exit.)

I can almost log in with MERCPPP, but it says BAD USERNAME OR PASSWORD even though I typed them in right!

Many ISP's require you to type in a prefix in front of your username. On some systems, it's #; on others, it's P; and on others it is the name of the service! Consult your ISP's online support web pages for clues. (You may need to look in surprising places; sometimes the needed info is buried in Mac Dialup or Unix Dialup support pages.)

In general, you should try Terminal Login first, rather than PAP. When setting up MERCPPP, don't enter in a password or username in the menus; do set Authentication to None; and do set Connection Type to "modem - terminal".

Specific instructions for a few popular ISPs follow.

I use Earthlink's national access, and I can't log in with MERCPPP!

Earthlink's list of dialup numbers says:
National numbers require ELN/ to prefix their login username. POPs followed by an "X" do not require the "ELN/".

I use Netcom, and I can't log in with MERCPPP!

Netcom's dialup documentation says:

(Also, there seem to be longer synonyms for #. One user reports that Netcom's own client software sometimes uses a prefix of us,ppp, for US dialup customers using PPP, ca,ppp, for Canadian dialup customers using PPP, us,slip, for US customers using SLIP, etc., and that he gets the same results with # and us,ppp,.)

I use The Concentric Network, and I can't log in with MERCPPP!

Concentric's PPP dialup documentation says:
Change your login name from "userid@slip" or "userid@tia" to "userid@ppp." (Do not include the quote marks.)

I use Sprynet, and I can't connect with MERCPPP!

  1. You need version 1.43 of the ppp dialer. See the instructions on upgrading to the latest dialer.
  2. When you connect, you should see some garbled stuff on the terminal screen. (This is 7 bit + parity ASCII; we need to switch to 8 bit + no parity ASCII.) Type + then the ENTER key, and you should see a HOST prompt. (The old version of the dialer refused to show the prompt here.)
  3. At the HOST prompt, type SPRY01 and press the ENTER key. (SPRY02 may also work.)
  4. Finally, enter your username (e.g. SPRY188123) and password. When you see another line of garble, press ALT+S and you should see the IPCP OPEN message. You can now EXIT the MERCPPP program and start MERCNET.

I use Compuserve, and I can't connect with MERCPPP!

  1. You need version 1.43 of the ppp dialer. See the instructions on upgrading to the latest dialer.
  2. When you connect, you should see some garbled stuff on the terminal screen. (This is 7 bit + parity ASCII; we need to switch to 8 bit + no parity ASCII.) Type + then the ENTER key, and you should see a HOST prompt. (The old version of the dialer refused to show the prompt here.)
  3. At the HOST prompt, type CIS and press the ENTER key.
  4. Finally, enter your userid followed by /GO:PPPCONNECT (e.g. 12345,6789/GO:PPPCONNECT) and password. When you see another line of garble, press ALT+S and you should see the IPCP OPEN message. You can now EXIT the MERCPPP program and start MERCNET.

I use ATT Worldnet, and I can't log in with MERCPPP!

  1. You need version 1.43 of the ppp dialer. See the instructions on upgrading to the latest dialer.
  2. Set MERCPPP to use PAP. This is documented in INTERNET.TXT, under "4F. CONFIGURING PPP TO LOGIN WITH PAP".
  3. Go into your Worldnet\Dialer subdirectory and print out the file ATT.SR. This file contains all the info you need to set up you PAP info.
  4. Run the MERCPPP.BAT file in your Mercenaries directory (I assume this is the same for DOS and WIN95 installations)
  5. At the Modem Configuration, enter the local number to dial in. This is line 4 in your ATT.SR file.
  6. At the next configuration menu, select ID & Password. Use the portion of the Name= (2nd line) line *including* the "" for your ID
  7. The next thing the program asks for is your Password. PAP uses a 16 character password, and this is NOT the password you picked and the time you signed up with AT&T Worldnet. This is line 3. NOTE: your password is case sensitive. If you don't get the case of the letters correct, the system won't let you log on.

How do I upgrade to the latest PPP dialer?

The dialer shipped with Mercs 1.00 was version 1.42, and had some problems with PAP and with connecting to Sprynet. Mercs 1.05 ships with version 1.43 of the dialer, which works better with PAP and 7-bit systems. You can tell which version you have by running MERCPPP and looking for the version number near the upper left of the screen. It should say "PPP Menu v1.43" if you have Mercs 1.05. For instructions on downloading the 1.05 patch, see Latest Version above.

If you installed the Mercs 1.05 patch over Mercs 1.00 after using 1.00's MERCPPP, you may still see version 1.42 of the dialer; to force MERCPPP to unpack the new version of pppshare.exe, you may need to delete the old PPPSHARE folder in your Mercs directory (either using the DOS commands

  CD \MERCS                     (or wherever you installed Mercs)
then run MERCPPP again to unpack and set up. (You'll have to enter your ISP's phone number and everything again, sorry... If you're ambitious, you can avoid this by saving the file NET.CFG before deleting the PPPSHARE folder, and copying it back in to the new PPPSHARE folder after briefly running MERCPPP to unpack PPPSHARE.) You should now be ready to connect with MERCPPP and MERCNET!

I can connect to my ISP using MERCPPP, and it says IPCP OPEN like it should, but there's nobody there in MercNet!

This is usually caused by having the wrong IP address. In particular, you should usually *not* enter an IP address in the MERCPPP menus; it will figure the address out for you (it changes every time).

I can get into a game using MERCPPP and MercNet but after a little while, the other player disappears, although I can still chat with them, and I still see his shadow!

This can be caused by excessive lag or excessive packet loss. (MercNet hides players it doesn't have good position info for.) Both excessive lag and excessive packet loss can be caused by trying to play against people who have bad connections or are too far away.

Excessive packet loss can also be caused by trying to put too many players into a game. The practical limit is 3 for 14.4 modems, and 5 for 28.8 modems.

Excessive lag can also be caused by error correction or compression protocols in your modem, because they gather data up into large blocks before sending, causing noticable delay.

To disable error correction and compression, you'll need to enter a Modem Init String. In MERCPPP, this is under Profile List/ F1 / Configure / Modem / Command Strings / Initialization String 3. When playing head-to-head with direct modem connections without MERCPPP, you add a new Modem Init String by editing MODEM.LST with a text editor (like Notepad or EDIT).

The right Modem Init String depends on your modem type; you build it by starting with AT and adding the commands from your modem's user guide for turning off compression, error correction and flow control. For example, here are the init string pieces for some common modem types (please e-mail corrections to any errors you find!):
No flow control No error correction No compression
Hayes &K0 &Q0
Rockwell &K0 &Q0 or \N &K0
USR &H0&I0 &M0 &K0
Microcom \Q0 \N1

You can also find a few possible examples in the file MODEM.LST. It's also worth searching the Web for modem init strings used by other multiplayer games (NOT init strings for general Internet use!), since most multiplayer games face the same problem of trying to minimize latency for small packets. For instance,

But be careful- a lot of the init strings listed on those are just plain wrong in that they don't turn off compression etc. like you want.

The best way to see if a particular init string will help without actually playing a game is to use the /ping command in MercNet 1.05. The smaller the ping time, the better the connection. If an init string lowers your ping time (all other things being equal!), it is good. Be careful not to compare apples to oranges, though - for a ping time comparison to be meaningful, it should be from a two-player room with the same player both times, preferably only a few minutes apart.

MercNet and Direct Ethernet Connections to the Internet

MercNet's built-in TCP/IP driver uses Packet Drivers to access your ethernet card or modem. Mercs ships with a Packet Driver for your modem, MERCPPP. If you want to use your ethernet card instead of your modem to play MercNet, you'll need to install a Packet Driver.

What is a packet driver and where do I get one?

A packet driver is a TSR that lets programs send and receive packets using the Packet Driver API.

Many Ethernet cards come with Packet Drivers on their setup floppy. Packet drivers for most cards can also be downloaded either from the card maker's Web page, or from

If you can't find a Packet Driver for your card, you can almost certainly find a Novell ODI driver, and there are instructions below on where to find a 'shim' that lets you use ODI drivers with MercNet.

The original DOS version of the popular KALI utility also uses packet drivers, so if you know someone who has DOS KALI running, they may be able to help you load a packet driver.

I have Netware's DOS client software installed. Isn't that a packet driver?

No, those are ODI drivers. Luckily, the ODI drivers you load in NWCLIENT can be adapted to work with Packet Driver clients by using ODIPKT, which you can get from and or There are a few documents that explain how in more detail, e.g. or In particular, you need to create a text file NET.CFG and load the program LSL.COM (which comes with Mercs) before loading the ODI driver TSR for your card and ODIPKT.

I have Microsoft's DOS client software installed. Isn't that a packet driver?

No, those are NDIS2 or NDIS3 drivers. The NDIS drivers you load via NET START may be adapted to work with Packet Driver clients using the shareware shims DIS_PKT.COM (for NDIS2) or NDIS3PKT (for NDIS3), but I haven't tried DIS_PKT.COM, and NDIS3PKT doesn't seem to work well with MercNet. It is probably better to install true packet drivers.

Once I have the packet drivers, how do I set up my computer so MercNet will recognize them?

First off, be sure you're in DOS. (Windows doesn't like DOS programs trying to access the Ethernet card using packet drivers.)

Run your card's packet driver before starting MercNet. (No other driver needed; don't run MERCPPP. That's for modems) If it doesn't print out a plausible ethernet address, stop- it may be having trouble finding the card. If possible, use the packet driver that came with the card. Otherwise, check the card maker's Web site or for drivers.

MercNet needs to know three things:

If your campus network supports BOOTP, great - delete the file WATTCP.CFG if present, and start MercNet. It will use BOOTP to learn those three things. Otherwise, you need to create a text file named WATTCP.CFG containing those three things. For example (but don't use these numbers):
  my_ip =
  netmask =
  gateway =

Whether or not you're using BOOTP, you can test whether tcp/ip is working by using the program WATPING that comes with Mercs. See the section below for how.

I think I have everything set up right, but when I try to connect to the server, I get "Unable to start communications".

There are several places you can look for trouble:
  1. When you load the packet driver, it should print out an ethernet address that looks like six random two-digit hexadecimal numbers separated by colons. If it prints out ff:ff:ff:ff:ff:ff or 0:0:0:0:0:0, it probably couldn't find your ethernet card, and you'll have to try a different base address.
  2. A program called WATPING.EXE is included with MercNet. You can use it to send a single packet to any Internet host; if everything is ok, the Internet host will echo your packet back to you, and WATPING will tell you "1 packet sent, 1 packet received." If you don't get a response, something is wrong.
    Here's how to run WATPING.EXE:
    1. If you haven't already, load your packet driver.
    2. Change directories to where Mercs is installed.
    3. Make sure a valid WATTCP.CFG with your Internet address and gateway is in the Mercs directory.
    4. Pick a nearby computer, e.g. your network's gateway, and run WATPING with that computer's IP address. For example, if your gateway is
      If it gets no response, there's a problem with your wattcp.cfg, your packet driver, your network connection, or your network's gateway.
    5. Ping the game server you're trying to connect to, e.g.
      If you got a response pinging your gateway, but you don't get a response pinging the game server, the Internet backbone or the game server are having trouble. If it reports that it got a response, great - everything's working, and MercNet should work for you.

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Dan Kegel
Copyright 1996, Activision