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+*os_msdos.txt*  For Vim version 7.0aa.  Last change: 2001 Sep 03
+
+
+		  VIM REFERENCE MANUAL    by Bram Moolenaar
+
+
+					*msdos* *ms-dos* *MSDOS* *MS-DOS*
+This file contains the particularities for the MS-DOS version of Vim.
+
+1. Two versions for MS-DOS	|msdos-versions|
+2. Known problems		|msdos-problems|
+3. Long file names		|msdos-longfname|
+4. Termcap codes		|msdos-termcap|
+5. Shifted arrow keys		|msdos-arrows|
+6. Filename extensions		|msdos-fname-extensions|
+7. Memory usage and limitations	|msdos-limitations|
+8. Symbolically linked files	|msdos-linked-files|
+9. Copy/paste in a dos box	|msdos-copy-paste|
+
+Additionally, there are a number of common Win32 and DOS items:
+File locations			|dos-locations|
+Using backslashes		|dos-backslash|
+Standard mappings		|dos-standard-mappings|
+Screen output and colors	|dos-colors|
+File formats			|dos-file-formats|
+:cd command			|dos-:cd|
+Interrupting			|dos-CTRL-Break|
+Temp files			|dos-temp-files|
+Shell option default		|dos-shell|
+
+For compiling Vim see src/INSTALL.pc.			*msdos-compiling*
+
+==============================================================================
+1. Two versions for MS-DOS				*msdos-versions*
+
+There are two versions of Vim that can be used with MS-DOS machines:
+
+							*dos16*
+Dos16 version	Can be used on any MS-DOS system, only uses up to 640 Kbyte of
+		memory.  Also runs on OS/2, Windows 95, and NT.  Excludes some
+		Vim-specific features (autocommands, syntax highlighting,
+		etc.).  Recommended for use on pre-386 machines.
+							*dos32*
+Dos32 version	Requires 386 processor and a |DPMI| driver, uses all
+		available memory.  Supports long file names and the Windows
+		clipboard, but NOT on Windows NT.  Recommended for MS-DOS,
+		Windows 3.1 and Windows 95.
+
+There are also two versions that run under Windows:
+Win32 version   Requires Windows 95 or Windows NT, uses all available
+		memory, supports long file names, etc.  Has some problems on
+		Windows 95.  Recommended for Windows NT.  See |os_win32.txt|
+Win32 GUI	Requirements like the Win32 version, but runs in its own
+		window, instead of a console.  Has scrollbars, menu, etc.
+		Recommended for Windows 95 and Windows NT.  See |gui-w32|.
+
+It is recommended to use the Dos32 or Win32 version.  Although the Dos16
+version is able to edit very big files, it quickly runs out of memory when
+making big changes.  Disabling undo helps: ":set ul=-1".  The screen updating
+of the Dos16 version is the fastest of the three on DOS or Windows 95; on
+Windows NT, the Win32 version is just as fast.
+
+								*DPMI*
+For the Dos32 version, you may need a DPMI driver when running in MS-DOS.  If
+you are running Windows or installed a clever memory manager, it will probably
+work already.  If you get the message "No DPMI", you need to install a DPMI
+driver.  Such a driver is included with the executable in CSDPMI4B.ZIP.  Run
+"cwsdpmi" just before starting Vim each time.  Or you might want to include
+"cwsdpmi -p" in your autoexec.bat to make it resident.  The latest version of
+"CSDPMI*.ZIP" can be obtained from: "ftp.neosoft.com:pub/users/s/sandmann".
+
+							*minimal-features*
+The 16 bit DOS version has been compiled with minimal features.  Check the
+|+feature-list| which ones are included (marked with a "T").
+You can include more features by editing feature.h and recompiling.
+
+==============================================================================
+2. Known problems					*msdos-problems*
+
+When using smartdrive (MS-DOS 6.x) with write-behind caching, it is possible
+that Vim will try to create a swap file on a read-only file system (e.g.
+write protected floppy).  You will then be given the message >
+	A serious disk error has occurred .., Retry (r)?
+There is nothing you can do but unprotect the floppy or switch off the
+computer.  Even CTRL-ALT-DEL will not get you out of this.  This is really a
+problem of smartdrive, not Vim.  Smartdrive works fine otherwise.  If this
+bothers you, don't use the write-behind caching.
+
+Vim can't read swap files that have been opened already, unless the "share"
+command has been used.  If you see stray warnings for existing swap files,
+include the "share" command in your config.sys or autoexec.bat (see your MSDOS
+documentation).
+
+The Dos16 version can only have about 10 files open (in a window or hidden) at
+one time.  With more files you will get error messages when trying to read or
+write a file, and for filter commands.  Or Vim runs out of memory, and random
+problems may result.
+
+The Dos32 version cannot have an unlimited number of files open at any one
+time.  The limit depends on the setting of FILES in your CONFIG.SYS. This
+defaults to 15; if you need to edit a lot of files, you should increase this.
+If you do not set FILES high enough, you can get strange errors, and shell
+commands may cause a crash!
+
+The Dos32 version can work with long file names.  When doing file name
+completion, matches for the short file name will also be found.  But this will
+result in the corresponding long file name.  For example, if you have the long
+file name "this_is_a_test" with the short file name "this_i~1", the command
+":e *1" will start editing "this_is_a_test".
+
+When using the Dos32 version and you run into problems with DPMI support,
+check if there is a program in your config.sys that eats resources.  One
+program known to cause this problem is "netx", which says "NetWare v. 3.26
+Workstation shell".  Replace it with version 3.32 to fix the problem.
+
+The Dos32 version will parse its arguments to handle quotation.  This is good
+to edit a file with spaces in its name, for example: >
+	vim "program files\accessories\ppp.scp"
+A side effect is that single quotes are removed.  Insert a backslash to avoid
+that.  For example, to edit the file "fi'le.txt": >
+	vim fi\'le.txt
+
+==============================================================================
+3. Long file names					*msdos-longfname*
+
+If the Dos32 version is run on Windows 95, it can use long file names.  It
+will work by default.  If you want to disable this, use this setting:
+	set LFN=N
+You can put this in your autoexec.bat file.
+
+Note: If you have installed DJGPP on your machine, you probably have a
+"djgpp.env" file, which contains "LFN=n".  You need to use "LFN=Y" to switch
+on using long file names then.
+
+==============================================================================
+4. Termcap codes					*msdos-termcap*
+
+If you want to use another output method (e.g., when using a terminal on a COM
+port), set the terminal name to "pcansi".  You can change the termcap options
+when needed (see |terminal-options|).  Note that the
+normal IBM ansi.sys does not support all the codes of the builtin pcansi
+terminal.  If you use ansi.sys, you will need to delete the termcap entries
+t_al and t_dl with >
+   :set t_al= t_dl=
+Otherwise, the screen will not be updated correctly.  It is better to use
+nansi.sys, nnansi.sys, or the like instead of ansi.sys.
+
+If you want to use Vim on a terminal connected to a COM: port, reset the
+'bioskey' option.  Otherwise the commands will be read from the PC keyboard.
+CTRL-C and CTRL-P may not work correctly with 'bioskey' reset.
+
+==============================================================================
+5. Shifted arrow keys					*msdos-arrows*
+
+Use CTRL-arrow-left and CTRL-arrow-right instead of SHIFT-arrow-left and
+SHIFT-arrow-right.  The arrow-up and arrow-down cannot be used with SHIFT or
+CTRL.
+
+==============================================================================
+6. Filename extensions				*msdos-fname-extensions*
+
+MS-DOS allows for only one file name extension.  Therefore, when appending an
+extension, the '.' in the original file name is replaced with a '_', the name
+is truncated to 8 characters, and the new extension (e.g., ".swp") is
+appended.  Two examples: "test.c" becomes "test_c.bak", "thisisat.est"
+becomes "thisisat.bak".  To reduce these problems, the default for
+'backupext' is "~" instead of ".bak".  The backup file for "thisisat.est"
+then becomes "thisisat.es~".  The 'shortname' option is not available,
+because it would always be set.
+
+==============================================================================
+7. Memory usage and limitations			*msdos-limitations*
+
+A swap file is used to store most of the text.  You should be able to edit
+very large files.  However, memory is used for undo and other things.  If you
+delete a lot of text, you can still run out of memory in the Dos16 version.
+
+If Vim gives an "Out of memory" warning, you should stop editing.  The result
+of further editing actions is unpredictable.  Setting 'undolevels' to 0 saves
+some memory.  Running the maze macros on a big maze is guaranteed to run out
+of memory, because each change is remembered for undo.  In this case set
+'undolevels' to a negative number.  This will switch off undo completely.
+
+						*msdos-clipboard-limits*
+In the Dos32 version, extended memory is used to avoid these problems.
+However, if you are using the clipboard, you can still run into memory
+limitations because the Windows clipboard can only communicate with Vim using
+Dos memory.  This means that the largest amount of text that can be sent to
+or received from the Windows clipboard is limited by how much free Dos memory
+is available on your system.
+
+You can usually maximize the amount of available Dos memory by adding the
+following lines to Dos's "config.sys" file: >
+
+	DOS=HIGH,UMB
+	DEVICE=C:\WINDOWS\himem.sys
+	DEVICE=C:\WINDOWS\emm386.exe RAM
+
+Modifying config.sys in this way will also help to make more memory available
+for the Dos16 version, if you are using that.
+
+In the Dos16 version the line length is limited to about 32000 characters.
+When reading a file the lines are automatically split.  But editing a line
+in such a way that it becomes too long may give unexpected results.
+
+==============================================================================
+8. Symbolically linked files			*msdos-linked-files*
+
+When using Vim to edit a symbolically linked file on a unix NFS file server,
+you may run into problems.
+When writing the file, Vim does not "write through" the symlink.  Instead, it
+deletes the symbolic link and creates a new file in its place.
+   On Unix, Vim is prepared for links (symbolic or hard).  A backup copy of
+the original file is made and then the original file is overwritten.  This
+assures that all properties of the file remain the same.  On non-Unix systems,
+the original file is renamed and a new file is written.  Only the protection
+bits are set like the original file.  However, this doesn't work properly when
+working on an NFS-mounted file system where links and other things exist.  The
+only way to fix this in the current version is not making a backup file, by
+":set nobackup nowritebackup"	|'writebackup'|
+
+==============================================================================
+9. Copy/paste in a dos box			*msdos-copy-paste*
+
+					*E450* *E451* *E452* *E453* *E454*
+The 32 bit version can copy/paste from/to the Windows clipboard directly.  Use
+the "* register.  Large amounts of text can be copied this way, but it must be
+possible to allocate memory for it, see |msdos-clipboard-limits|.  When moving
+text from one Vim to another, the type of the selection
+(characterwise/linewise/blockwise) is passed on.
+
+In other versions, the following can be used.
+
+(posted to comp.editors by John Velman <velman@igate1.hac.com>)
+
+How to copy/paste text from/to vim in a dos box:
+
+1) to get VIM to run in a window, instead of full screen, press alt+enter.
+   This toggles back and forth between full screen and a dos window.
+   NOTE: In Windows 95 you must have the property "Fast Pasting" unchecked!
+   In the properties dialog box for the MS-DOS window, go to "MS-DOS
+   Prompt/Misc/Fast pasting" and make sure that it is NOT checked.
+   To make this permanent, change the properties for
+   "\windows\system\conagent.exe" (from Philip Nelson, unverified).
+
+2) To paste something _into_ Vim, put Vim in insert mode.
+
+3) put the text you want to paste on the windows clipboard.
+
+4) Click the control box in the upper left of the Vim window. (This looks
+   like a big minus sign). If you don't want to use the mouse, you can get
+   this with alt+spacebar.
+5) on the resulting dropdown menu choose "Edit"
+6) on the child dropdown menu choose "Paste"
+
+To copy something from the Vim window to the clipboard,
+
+1) select the control box to get the control drop down menu.
+2) select "Edit".
+3) select "Mark"
+4) using either the keys or the mouse, select the part of the Vim window that
+   you want to copy. To use the keys, use the arrow keys, and hold down shift
+   to extend the selection.
+5) when you've completed your selection, press 'enter.' The selection
+   is now in the windows clipboard. By the way, this can be any
+   rectangular selection, for example columns 4-25 in rows 7-10. It can
+   include anything in the VIM window: the output of a :!dir, for
+   example.
+
+ vim:tw=78:ts=8:ft=help:norl: