About Deb16fw

 Deb16fw is a debugger for 16-bit windows applications. Its
 advantages/disadvantages are:

 + may trace mode switches
 + should be able to debug applications with mixed (16/32-bit)
   code segments
 + dissassembler knows full pentium instruction set
   including MMX and ISSE.
 + a second video adapter is supported. As well, the debugger
   may be controled by COM port communication.
 + automatically uses debug registers if it cannot write
   a breakpoint, so single-stepping through ROM is no problem.
 + by using "hard" mode is able to debug Win32 apps on Windows 9x
   systems. This may be useful if code must be traced down to the
   16-bit windows code.
 - has a simple line-oriented user interface.
 - is unable to debug at source code level
 - doesn't work on NT


 How to start the Debugger

 Create a link for deb16fw.exe. Executing deb16fw without a parameter
 will start the debugger without activating it. To activate the debugger
 double-click the symbol or right-click it and select menu item
 "Enter debugger". On Windows 3x/9x systems the screen will be
 switched to text mode, on Windows NT/2k/XP a console window will
 be opened.


 How to use Deb16fw

 Deb16fw has an integrated help function which describes most
 of its features. To start with it type

 - "?" for a list of available commands.
 - "? ?" to display help index. Each topic displayed here may
   be displayed in detail by entering "? <topic>"
 - "? keys" displays some help about keyboard usage inside Deb16f
 - "? cmdline" displays format of command line accepted by Deb16f

 A debuggee is loaded by "Load" command. Type "? L" to display
 format of this command. After a debuggee is loaded you may single-
 step through it by pressing F8 or just enter "G breakpoint"
 to execute debuggee in real-time until breakpoint is reached.

 Known Problems
 
 - On win9x systems some graphics driver will not support switching
   the screen to text mode. In such cases the debugger can only be 
   used with alternative output devices. Source code for the video
   mode switching dll (deb16fvw.dll) is included, though, so it may
   be adjusted.
 - On win9x systems starting the debugger from a command line should 
   only be done together with the /Q option as argument.
 - On 2K/XP systems some commands (.SFT, .CDS) don't work properly.
 - On 2K/XP systems the "type" command doesn't work for standard output
   device.
 - On 2K/XP systems currently the debugger is unable to indicate its
   idle state, so it will consume cpu time while waiting for a key press.

 Files Overview

 - deb16fw.exe:  a simple executable to load the debugger core
 - deb16fw.ovl:  the debugger itself
 - deb16fwh.dll  32-bit dll for PE file support and video output
                 on 2K/XP systems
 - debxxvdd.dll: a VDD to support the debugger when running in NTVDM.
 - deb16fwp.exe  console terminal for video output on 2K/XP platforms
 - deb16fwv.dll  switch video modes in win3x/win9x (16-bit dll)
 - deb16fwv.zip  source code for deb16fwv.dll
 - rmdbghlp.bin: helper code which will be loaded into
                 conventional dos memory to provide support for
                 real/v86 mode debugging.
 - debxxf.hlp:   a text file which will be loaded by the debugger
                 at startup. contains help topics and error messages.
 - debxxf.mac:   macros for the debugger loaded at startup.
 - debxxf.ini:   profile file for all versions of the debugger
 - showfile.dll: a fullscreen hex editor which is used for the
                 debugger's "type" command (16-bit dll).
 - symbhdlw.dll: gets exports as symbols (16-bit dll)
 - deb16fw.txt   the file you are reading just now.


 Copyright

 Deb16fw is freeware. Copyright 1993-2007 Japheth.

 Japheth