User Bulletin:IMAPACHE002-1

Apache - April 12, 1996 - Head To Head Using a Modem

A new patch is available for Apache which enhances the Head to Head play
over a modem.  This patch is available via download of the file: apchptch.exe.
Both players must have the new version downloaded onto their machines to play
Head to Head via modem.

Improvements:

- Modem communications have implemented a "Guaranteed Packet Delivery"
  system.  This allows the game to detect and retransmit dropped or corrupt data 
  passed between the two players.  This corrects many of the lockup and aborting 
  problems of previous versions.
- Enhanced machine to machine communications during the startup and menu 
  screens after the connection is established.  This adds several features: only
  one player needs to press the "Start Game" on the menu screen or "Exit" on the
  map screen, and both machines respond; errors in mode selection can be
  corrected and the game started again; once a game is over the modes can be
  changed and restarted without breaking the connection.
- In Leader/Wingman mode, when one of the players dies, that player will assume
  a "chase view" and watch the surviving player complete the mission.

Installation:

- Download the apchptch.exe file into your Apache directory.
- Rename the old Apache.bat, Apache95.exe, and Prefs.cfg file to different file 
  names prior to executing the apchptch.exe installation program.
- Run "apchptch.exe" which installs the new Apache.bat, Apache95.exe, and 
  Prefs.cfg files.
- Run "Apache" and reenter the Preferences screen information.
- When entering the two player screen for the first time, be sure to select the
  proper "COM" port, (and IRQ if non standard), prior to pressing the "Modem"
  button.  When the wrong COM port is selected, a "Time out" error will occur
  several times and then prompt the user to validate the modem connection.
  Press the "Direct" button and select an alternate COM port.  For external
  modems, always check that the modem is connected and turned on.

General:
Modem communications are always a problem to resolve due to shear number of 
different modems and phone companies.  The following recommendations are
provided to enhance Apache’s performance and improve the Head to Head game play.

- Insure all connections to external modems and to the phone line are well
  seated and tight.
- Select the initialization sequence that best matches your modem.  (i.e. all
  responses are "OK" with no errors).
- Select a speed that is equal to or at most one speed higher than the expected
  line connection speed.  Example:  the expected connection is 28,800bps,
  select the modem communication of 28,800bps, or 38,400bps at most.
  Increasing the modem to computer communication speed may actually decrease
  the performance of the game.
- If an external modem is used, watch the receive / transmit lights during the
  initial parts of the game. If the lights hesitate at a constant rate, the
  connection is fairly good.  If the lights flicker with unsteady beats, or
  intermittent hesitation, the line connection is noisy.  It may be wise to
  exit the game, (e.g. Cntl Q),  and hang up the modem, (e.g. hang up button),
  and re-dial to get a new connection.  Once a good connection is made, you can
  hang on to it when exiting the game and starting a new game.
- If a connection is lost for any reason, and the menu screen indicates that it
  has reinitialized,  depress the "hangup modem" button and then the "Modem"
  button to be sure everything is reset.  This may not be necessary, but is
  performed just to be sure everything is still OK.


Advanced:
- Review your modem manual and the selected initialization sequence to insure
  the following modes are selected:
- CTS/RTS hardware hand shake enabled.
- V.42/MNP4 or other error correction negotiated between modems.
- Data Compression disabled.  Data compression at higher speeds may slow frame 
  rate.
- If the modem has a programmable "line quality monitor / retrain" mode, turn
  it off.  Look for "%E0" for Hayes compatible modems  This works well for bulk
  data transfers like file downloads, but in time critical, low latency
  dependent transmissions like game play, the modem changing baud rates or
  error correction style can be fatal.  A single "retraining" cycle for a modem
  can be several seconds. This time delay may cause the game to "time out".
  Secondly, if the resultant negotiations result in a much slower Baud rate,
  each data transmission, (i.e. packet), could "time out" on every transfer
  since the game was calibrated to the initial connections response times.
- With US Robotics modems, it is recommended that you force the modem to modem 
  baud rate to a non standard baud rate (i.e. not 14400, or 28,800).  Modem to
  modem baud rates of 12000, 24000, or 21600 work much better.  This is
  accomplished by adding a AT&N7,  AT&N12, or AT&N11 respectively via the
  command field. 
- Observe that no errors are reported during initialization.  If so, correct
  them.