The Configuration Process

After you have assembled the required items, follow these steps to prepare the MUT for remote debugging:

• Connect the Modem to the MUT.

  Connect one end of the data cable to the modem, and the other end to the serial port on the MUT. If the MUT has more than one serial port, connect the cable to the port configured as COM2 (the debug kernel uses COM2 by default). On PS/2 systems, the reference diskette can tell you which port is configured as COM2. Connect the telephone line to the modem, and power the modem on.

• Program the modem for DEBUG operation:

  Programming the modem may be a complex process, depending on the type of modem and the intended use. There are two ways to program the modem:

  • Quick programming for single debug use

  • Full programming for "permanent" debug use.
  The "quick" method is simple, but the modem will not be programmed to recover from loss of power or repeated calls. The "full" method allows the modem to be programmed once, and then used whenever debugging is needed.

  The "quick" programming is performed by the debug kernel itself through use of the KDB.INI file. In addition to containing start up commands for the debugger KDB.INI can also contain modem initialisation strings coded as operands to the Kernel Debugger ? command. For this reason, the modem must be connected and powered on when the MUT is booted, and cannot be powered off until debugging is complete.

  The first lines of the KDB.INI may will be COM port selection and parameters if defaults are not suitable, for example:

• B 1200t 1
  (Set debugger for 1200 bps, comm port 1)
  Following this are the modem initialisation strings, which are unique to each type of modem. The commands in the initialisation string must:

  • Activate "auto-answer"

  • Lock the DTE at 9600 bps

  • Activate XON/XOFF flow control

  • Ignore the DTR signal (not supplied by the debug kernel)

  • Suppress result codes.
  The remaining lines of the KDB.INI file may contain other debugging commands. The last of these is normally G.

  The "quick" programming strings for several popular modems are as follows.

• AT&F E0 Q1 &B1 &H2 &I2 &D0 S0=1"
  US Robotics HST and Dual Standard
  ? "AT&F2 E0 Q2 &D0 &K4 S0=1"
  Supra FAX/Modem V.32bis
  ? "AT&F E0 Q1 &D0 \Q1 S0=1"
  Intel 14.4EX
  An alternative "quick" technique for entering the Hayes modem initialisation commands, which avoids the use of KDB.INI is illustrated by the following example. This example assumes that the default COM2 port is to be used:

  1. In CONFIG.SYS add the following line
  
         RUN=C:\OS2\CMD.EXE /K C:\MODEM.CMD
  
  2. Edit a file called MODEM.CMD and enter the following two lines
  
         MODE COM2:9600,N,8,1
         COPY MODEM COM2
  
  3. Edit a file called MODEM and enter the following line
  
         AT&K4&D0S0=1&W
  

  To use "Full" programming, you will configure the modem with the same features as in "quick" programming, but the settings will be stored in the modem's firmware (or set in modem switches). Determining how to store these settings can be difficult. A thorough study of the modem manual may be required. To program the modem, use a terminal emulation program (for example, the SOFTERM program that is supplied with OS/2). When programming the modem, Set the terminal program for 9600 BPS operation, and type the appropriate modem string. Since the initialisation string instructs the modem to suppress result codes, the modem will not return a response. The "FULL" programming strings for several modems are:

  AT&F &B1 &H2 &I2 &W

  US Robotics HST and Dual Standard
  AT&F2 E0 Q2 &D0 &K4 S0=1 &W
  Supra FAX/Modem V.32bis
  AT&F E0 Q1 &D0 \Q1 S0=1 &W
  Intel 14.4EX
  NOTE: The US Robotics HST Dual Standard does not store all settings, but has external switches instead. After programming the modem, set the switches as follows:

• ON
  (DTR forced ON)
  2=don't care
  (result code type)
  3=OFF
  (result code suppressed)
  4=ON
  (command echo suppressed)
  5=OFF
  (auto-answer enabled)
  6=don't care
  (carrier detect function)
  7=ON
  (result code in originate mode only)
  8=ON
  (AT commands enabled)
  9=ON
  (don't disconnect for +++)
  10=OFF
  (load NVRAM at power-on)
  QUAD=OFF
  (normal connect - ON if null modem cable used)

  Once the modem is connected, and programmed, the system should be ready for remote debugging. Re-boot the system with the debug kernel installed. When the telephone rings, the debug modem should answer the phone, and establish connection with the caller. The modem-to-kernel speed should remain at 9600 bps (the default speed used by the debug kernel), but the modem-to-modem speed can be whatever is used by the remote modem. If both modems support error correction, correction will be used.

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