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[Emacs-diffs] Changes to emacs/man/msdog.texi

From: Karl Berry
Subject: [Emacs-diffs] Changes to emacs/man/msdog.texi
Date: Sun, 09 Apr 2006 22:40:36 +0000

Index: emacs/man/msdog.texi
diff -u emacs/man/msdog.texi:1.43 emacs/man/msdog.texi:1.44
--- emacs/man/msdog.texi:1.43   Sun Feb  5 22:41:31 2006
+++ emacs/man/msdog.texi        Sun Apr  9 22:40:34 2006
@@ -2,307 +2,28 @@
 @c Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1997, 2000, 2001,
 @c   2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
 @c See file emacs.texi for copying conditions.
address@hidden MS-DOS, Manifesto, Mac OS, Top
address@hidden Emacs and Microsoft Systems
address@hidden MS-DOG
address@hidden Emacs and Microsoft Windows, Manifesto, Mac OS, Top
address@hidden Emacs and Microsoft Windows
 @cindex Microsoft Windows
address@hidden MS-DOS peculiarities
-  This section briefly describes the peculiarities of using Emacs on
-the MS-DOS ``operating system'' (also known as ``MS-DOG'') and on
-Microsoft Windows.
-  If you build Emacs for MS-DOS, the binary will also run on Windows
-3.X, Windows NT, Windows 9X/ME, Windows 2000, or OS/2 as a DOS
-application; all the of this chapter applies for all of those systems,
-if you use an Emacs that was built for MS-DOS.
-  However, if you want to use Emacs on Windows, you would normally
-build Emacs specifically for Windows.  If you do that, most of this
-chapter does not apply; instead, you get behavior much closer to what
-is documented in the rest of the manual, including support for long
-file names, multiple frames, scroll bars, mouse menus, and
-subprocesses.  However, the section on text files and binary files
-does still apply.  There are also two sections at the end of this
-chapter which apply specifically for the Windows version.
+  This section describes peculiarities of using Emacs on Microsoft
+Windows.  Information about Emacs and Microsoft's older MS-DOS
+``operating system'' (also known as ``MS-DOG'') is now in a separate
+manual (@inforef{MS-DOG,, emacs-xtra}).
+  Iif you want to use Emacs on Windows, you would normally build Emacs
+specifically for Windows.  If you do that, the behavior is reasonably
+similar to what is documented in the rest of the manual, including
+support for long file names, multiple frames, scroll bars, mouse
+menus, and subprocesses.  However, a few special considerations apply,
+and they are described here.
-* Keyboard: MS-DOS Keyboard.   Keyboard conventions on MS-DOS.
-* Mouse: MS-DOS Mouse.         Mouse conventions on MS-DOS.
-* Display: MS-DOS Display.     Fonts, frames and display size on MS-DOS.
-* Files: MS-DOS File Names.    File name conventions on MS-DOS.
-* Text and Binary::            Text files on MS-DOS use CRLF to separate lines.
-* Printing: MS-DOS Printing.   How to specify the printer on MS-DOS.
-* I18N: MS-DOS and MULE.       Support for internationalization on MS-DOS.
-* Processes: MS-DOS Processes. Running subprocesses on MS-DOS.
+* Text and Binary::            Text files use CRLF to terminate lines.
 * Windows Processes::          Running subprocesses on Windows.
 * Windows System Menu::        Controlling what the ALT key does.
 @end menu
address@hidden MS-DOS Keyboard
address@hidden Keyboard Usage on MS-DOS
address@hidden DEL @r{(MS-DOS)}
address@hidden BS @r{(MS-DOS)}
-  The key that is called @key{DEL} in Emacs (because that's how it is
-designated on most workstations) is known as @key{BS} (backspace) on a
-PC.  That is why the PC-specific terminal initialization remaps the
address@hidden key to act as @key{DEL}; the @key{DELETE} key is remapped to act
-as @kbd{C-d} for the same reasons.
address@hidden C-g @r{(MS-DOS)}
address@hidden C-BREAK @r{(MS-DOS)}
address@hidden quitting on MS-DOS
-  Emacs built for MS-DOS recognizes @address@hidden as a quit
-character, just like @kbd{C-g}.  This is because Emacs cannot detect
-that you have typed @kbd{C-g} until it is ready for more input.  As a
-consequence, you cannot use @kbd{C-g} to stop a running command
-(@pxref{Quitting}).  By contrast, @address@hidden @emph{is} detected
-as soon as you type it (as @kbd{C-g} is on other systems), so it can be
-used to stop a running command and for emergency escape
-(@pxref{Emergency Escape}).
address@hidden Meta (under MS-DOS)
address@hidden Hyper (under MS-DOS)
address@hidden Super (under MS-DOS)
address@hidden dos-super-key
address@hidden dos-hyper-key
-  The PC keyboard maps use the left @key{ALT} key as the @key{META} key.
-You have two choices for emulating the @key{SUPER} and @key{HYPER} keys:
-choose either the right @key{CTRL} key or the right @key{ALT} key by
-setting the variables @code{dos-hyper-key} and @code{dos-super-key} to 1
-or 2 respectively.  If neither @code{dos-super-key} nor
address@hidden is 1, then by default the right @key{ALT} key is
-also mapped to the @key{META} key.  However, if the MS-DOS international
-keyboard support program @file{KEYB.COM} is installed, Emacs will
address@hidden map the right @key{ALT} to @key{META}, since it is used for
-accessing characters like @kbd{~} and @kbd{@@} on non-US keyboard
-layouts; in this case, you may only use the left @key{ALT} as @key{META}
address@hidden C-j @r{(MS-DOS)}
address@hidden dos-keypad-mode
-  The variable @code{dos-keypad-mode} is a flag variable that controls
-what key codes are returned by keys in the numeric keypad.  You can also
-define the keypad @key{ENTER} key to act like @kbd{C-j}, by putting the
-following line into your @file{_emacs} file:
-;; @r{Make the @key{ENTER} key from the numeric keypad act as @kbd{C-j}.}
-(define-key function-key-map [kp-enter] [?\C-j])
address@hidden smallexample
address@hidden MS-DOS Mouse
address@hidden Mouse Usage on MS-DOS
address@hidden mouse support under MS-DOS
-  Emacs on MS-DOS supports a mouse (on the default terminal only).
-The mouse commands work as documented, including those that use menus
-and the menu bar (@pxref{Menu Bar}).  Scroll bars don't work in
-MS-DOS Emacs.  PC mice usually have only two buttons; these act as
address@hidden and @kbd{Mouse-2}, but if you press both of them
-together, that has the effect of @kbd{Mouse-3}.  If the mouse does have
-3 buttons, Emacs detects that at startup, and all the 3 buttons function
-normally, as on X.
-  Help strings for menu-bar and pop-up menus are displayed in the echo
-area when the mouse pointer moves across the menu items.
-Highlighting of mouse-sensitive text (@pxref{Mouse References}) is also
address@hidden mouse, set number of buttons
address@hidden msdos-set-mouse-buttons
-  Some versions of mouse drivers don't report the number of mouse
-buttons correctly.  For example, mice with a wheel report that they
-have 3 buttons, but only 2 of them are passed to Emacs; the clicks on
-the wheel, which serves as the middle button, are not passed.  In
-these cases, you can use the @kbd{M-x msdos-set-mouse-buttons} command
-to tell Emacs how many mouse buttons to expect.  You could make such a
-setting permanent by adding this fragment to your @file{_emacs} init
-;; @r{Treat the mouse like a 2-button mouse.}
-(msdos-set-mouse-buttons 2)
address@hidden example
address@hidden Windows clipboard support
-  Emacs built for MS-DOS supports clipboard operations when it runs on
-Windows.  Commands that put text on the kill ring, or yank text from the
-ring, check the Windows clipboard first, just as Emacs does on the X
-Window System (@pxref{Mouse Commands}).  Only the primary selection and
-the cut buffer are supported by MS-DOS Emacs on Windows; the secondary
-selection always appears as empty.
-  Due to the way clipboard access is implemented by Windows, the
-length of text you can put into the clipboard is limited by the amount
-of free DOS memory that is available to Emacs.  Usually, up to 620KB of
-text can be put into the clipboard, but this limit depends on the system
-configuration and is lower if you run Emacs as a subprocess of
-another program.  If the killed text does not fit, Emacs outputs a
-message saying so, and does not put the text into the clipboard.
-  Null characters also cannot be put into the Windows clipboard.  If the
-killed text includes null characters, Emacs does not put such text into
-the clipboard, and displays in the echo area a message to that effect.
address@hidden dos-display-scancodes
-  The variable @code{dos-display-scancodes}, when address@hidden,
-directs Emacs to display the @acronym{ASCII} value and the keyboard scan code 
-each keystroke; this feature serves as a complement to the
address@hidden command, for debugging.
address@hidden MS-DOS Display
address@hidden Display on MS-DOS
address@hidden faces under MS-DOS
address@hidden fonts, emulating under MS-DOS
-  Display on MS-DOS cannot use font variants, like bold or italic,
-but it does support
-multiple faces, each of which can specify a foreground and a background
-color.  Therefore, you can get the full functionality of Emacs packages
-that use fonts (such as @code{font-lock}, Enriched Text mode, and
-others) by defining the relevant faces to use different colors.  Use the
address@hidden command (@pxref{Frame Parameters}) and the
address@hidden command (@pxref{Faces}) to see what colors and
-faces are available and what they look like.
-  @xref{MS-DOS and MULE}, later in this chapter, for information on
-how Emacs displays glyphs and characters that aren't supported by the
-native font built into the DOS display.
address@hidden cursor shape on MS-DOS
-  When Emacs starts, it changes the cursor shape to a solid box.  This
-is for compatibility with other systems, where the box cursor is the
-default in Emacs.  This default shape can be changed to a bar by
-specifying the @code{cursor-type} parameter in the variable
address@hidden (@pxref{Creating Frames}).  The MS-DOS
-terminal doesn't support a vertical-bar cursor, so the bar cursor is
-horizontal, and the @address@hidden parameter, if specified by the
-frame parameters, actually determines its height.  For this reason,
-the @code{bar} and @code{hbar} cursor types produce the same effect on
-MS-DOS.  As an extension, the bar cursor specification can include the
-starting scan line of the cursor as well as its width, like this:
- '(cursor-type bar @var{width} . @var{start})
address@hidden example
-In addition, if the @var{width} parameter is negative, the cursor bar
-begins at the top of the character cell.
address@hidden frames on MS-DOS
-  The MS-DOS terminal can only display a single frame at a time.  The
-Emacs frame facilities work on MS-DOS much as they do on text-only
-terminals (@pxref{Frames}).  When you run Emacs from a DOS window on
-MS-Windows, you can make the visible frame smaller than the full
-screen, but Emacs still cannot display more than a single frame at a
address@hidden frame size under MS-DOS
address@hidden mode4350
address@hidden mode25
-  The @code{mode4350} command switches the display to 43 or 50
-lines, depending on your hardware; the @code{mode25} command switches
-to the default 80x25 screen size.
-  By default, Emacs only knows how to set screen sizes of 80 columns by
-25, 28, 35, 40, 43 or 50 rows.  However, if your video adapter has
-special video modes that will switch the display to other sizes, you can
-have Emacs support those too.  When you ask Emacs to switch the frame to
address@hidden rows by @var{m} columns dimensions, it checks if there is a
-variable called @address@hidden@var{m}}, and if so,
-uses its value (which must be an integer) as the video mode to switch
-to.  (Emacs switches to that video mode by calling the BIOS @code{Set
-Video Mode} function with the value of
address@hidden@address@hidden in the @code{AL} register.)
-For example, suppose your adapter will switch to 66x80 dimensions when
-put into video mode 85.  Then you can make Emacs support this screen
-size by putting the following into your @file{_emacs} file:
-(setq screen-dimensions-66x80 85)
address@hidden example
-  Since Emacs on MS-DOS can only set the frame size to specific
-supported dimensions, it cannot honor every possible frame resizing
-request.  When an unsupported size is requested, Emacs chooses the next
-larger supported size beyond the specified size.  For example, if you
-ask for 36x80 frame, you will get 40x80 instead.
-  The variables @address@hidden@var{m}} are used only
-when they exactly match the specified size; the search for the next
-larger supported size ignores them.  In the above example, even if your
-VGA supports 38x80 dimensions and you define a variable
address@hidden with a suitable value, you will still get
-40x80 screen when you ask for a 36x80 frame.  If you want to get the
-38x80 size in this case, you can do it by setting the variable named
address@hidden with the same video mode value as
-  Changing frame dimensions on MS-DOS has the effect of changing all the
-other frames to the new dimensions.
address@hidden MS-DOS File Names
address@hidden File Names on MS-DOS
address@hidden file names under MS-DOS
address@hidden init file, default name under MS-DOS
-  MS-DOS normally uses a backslash, @samp{\}, to separate name units
-within a file name, instead of the slash used on other systems.  Emacs
-on MS-DOS permits use of either slash or backslash, and also knows
-about drive letters in file names.
-  On MS-DOS, file names are case-insensitive and limited to eight
-characters, plus optionally a period and three more characters.  Emacs
-knows enough about these limitations to handle file names that were
-meant for other operating systems.  For instance, leading dots @samp{.}
-in file names are invalid in MS-DOS, so Emacs transparently converts
-them to underscores @samp{_}; thus your default init file (@pxref{Init
-File}) is called @file{_emacs} on MS-DOS.  Excess characters before or
-after the period are generally ignored by MS-DOS itself; thus, if you
-visit the file @file{LongFileName.EvenLongerExtension}, you will
-silently get @file{longfile.eve}, but Emacs will still display the long
-file name on the mode line.  Other than that, it's up to you to specify
-file names which are valid under MS-DOS; the transparent conversion as
-described above only works on file names built into Emacs.
address@hidden backup file names on MS-DOS
-  The above restrictions on the file names on MS-DOS make it almost
-impossible to construct the name of a backup file (@pxref{Backup
-Names}) without losing some of the original file name characters.  For
-example, the name of a backup file for @file{docs.txt} is
address@hidden even if single backup is used.
address@hidden file names under Windows 95/NT
address@hidden long file names in DOS box under Windows 95/NT
-  If you run Emacs as a DOS application under Windows 9X, Windows ME, or
-Windows 2000, you can turn on support for long file names.  If you do
-that, Emacs doesn't truncate file names or convert them to lower case;
-instead, it uses the file names that you specify, verbatim.  To enable
-long file name support, set the environment variable @env{LFN} to
address@hidden before starting Emacs.  Unfortunately, Windows NT doesn't allow
-DOS programs to access long file names, so Emacs built for MS-DOS will
-only see their short 8+3 aliases.
address@hidden @env{HOME} directory under MS-DOS
-  MS-DOS has no notion of home directory, so Emacs on MS-DOS pretends
-that the directory where it is installed is the value of the @env{HOME}
-environment variable.  That is, if your Emacs binary,
address@hidden, is in the directory @file{c:/utils/emacs/bin}, then
-Emacs acts as if @env{HOME} were set to @samp{c:/utils/emacs}.  In
-particular, that is where Emacs looks for the init file @file{_emacs}.
-With this in mind, you can use @samp{~} in file names as an alias for
-the home directory, as you would on GNU or Unix.  You can also set
address@hidden variable in the environment before starting Emacs; its
-value will then override the above default behavior.
-  Emacs on MS-DOS handles the directory name @file{/dev} specially,
-because of a feature in the emulator libraries of DJGPP that pretends
-I/O devices have names in that directory.  We recommend that you avoid
-using an actual directory named @file{/dev} on any disk.
 @node Text and Binary
 @section Text Files and Binary Files
 @cindex text and binary files on MS-DOS/MS-Windows
@@ -419,379 +140,6 @@
 the file-name patterns in @code{file-name-buffer-file-type-alist}, the
 EOL conversion is determined by @code{file-name-buffer-file-type-alist}.
address@hidden MS-DOS Printing
address@hidden Printing and MS-DOS
-  Printing commands, such as @code{lpr-buffer} (@pxref{Printing}) and
address@hidden (@pxref{PostScript}) can work in MS-DOS and
-MS-Windows by sending the output to one of the printer ports, if a
-Posix-style @code{lpr} program is unavailable.  The same Emacs
-variables control printing on all systems, but in some cases they have
-different default values on MS-DOS and MS-Windows.
address@hidden printer-name @r{(MS-DOS)}
-  If you want to use your local printer, printing on it in the usual DOS
-manner, then set the Lisp variable @code{lpr-command} to @code{""} (its
-default value) and @code{printer-name} to the name of the printer
-port---for example, @code{"PRN"}, the usual local printer port (that's
-the default), or @code{"LPT2"}, or @code{"COM1"} for a serial printer.
-You can also set @code{printer-name} to a file name, in which case
-``printed'' output is actually appended to that file.  If you set
address@hidden to @code{"NUL"}, printed output is silently
-discarded (sent to the system null device).
-  On MS-Windows, when the Windows network software is installed, you can
-also use a printer shared by another machine by setting
address@hidden to the UNC share name for that printer---for example,
address@hidden"//joes_pc/hp4si"}.  (It doesn't matter whether you use forward
-slashes or backslashes here.)  To find out the names of shared printers,
-run the command @samp{net view} at a DOS command prompt to obtain a list
-of servers, and @samp{net view @var{server-name}} to see the names of printers
-(and directories) shared by that server.  Alternatively, click the
address@hidden Neighborhood} icon on your desktop, and look for machines
-which share their printers via the network.
address@hidden @samp{net use}, and printing on MS-Windows
address@hidden networked printers (MS-Windows)
-  If the printer doesn't appear in the output of @samp{net view}, or
-if setting @code{printer-name} to the UNC share name doesn't produce a
-hardcopy on that printer, you can use the @samp{net use} command to
-connect a local print port such as @code{"LPT2"} to the networked
-printer.  For example, typing @kbd{net use LPT2:
-Note that the @samp{net use} command requires the UNC share name to be
-typed with the Windows-style backslashes, while the value of
address@hidden can be set with either forward- or backslashes.}
-causes Windows to @dfn{capture} the LPT2 port and redirect the printed
-material to the printer connected to the machine @code{joes_pc}.
-After this command, setting @code{printer-name} to @code{"LPT2"}
-should produce the hardcopy on the networked printer.
-  With some varieties of Windows network software, you can instruct
-Windows to capture a specific printer port such as @code{"LPT2"}, and
-redirect it to a networked printer via the @address@hidden
-Panel->Printers}} applet instead of @samp{net use}.
-  Some printers expect DOS codepage encoding of address@hidden text, even
-though they are connected to a Windows machine which uses a different
-encoding for the same locale.  For example, in the Latin-1 locale, DOS
-uses codepage 850 whereas Windows uses codepage 1252.  @xref{MS-DOS and
-MULE}.  When you print to such printers from Windows, you can use the
address@hidden RET c} (@code{universal-coding-system-argument}) command before
address@hidden lpr-buffer}; Emacs will then convert the text to the DOS
-codepage that you specify.  For example, @kbd{C-x RET c cp850-dos RET
-M-x lpr-region RET} will print the region while converting it to the
-codepage 850 encoding.  You may need to create the @address@hidden
-coding system with @kbd{M-x codepage-setup}.
-  If you set @code{printer-name} to a file name, it's best to use an
-absolute file name.  Emacs changes the working directory according to
-the default directory of the current buffer, so if the file name in
address@hidden is relative, you will end up with several such
-files, each one in the directory of the buffer from which the printing
-was done.
address@hidden print-buffer @r{(MS-DOS)}
address@hidden print-region @r{(MS-DOS)}
address@hidden lpr-headers-switches @r{(MS-DOS)}
-  The commands @code{print-buffer} and @code{print-region} call the
address@hidden program, or use special switches to the @code{lpr} program, to
-produce headers on each printed page.  MS-DOS and MS-Windows don't
-normally have these programs, so by default, the variable
address@hidden is set so that the requests to print page
-headers are silently ignored.  Thus, @code{print-buffer} and
address@hidden produce the same output as @code{lpr-buffer} and
address@hidden, respectively.  If you do have a suitable @code{pr}
-program (for example, from GNU Textutils), set
address@hidden to @code{nil}; Emacs will then call
address@hidden to produce the page headers, and print the resulting output as
-specified by @code{printer-name}.
address@hidden print-region-function @r{(MS-DOS)}
address@hidden lpr usage under MS-DOS
address@hidden lpr-command @r{(MS-DOS)}
address@hidden lpr-switches @r{(MS-DOS)}
-  Finally, if you do have an @code{lpr} work-alike, you can set the
-variable @code{lpr-command} to @code{"lpr"}.  Then Emacs will use
address@hidden for printing, as on other systems.  (If the name of the
-program isn't @code{lpr}, set @code{lpr-command} to specify where to
-find it.)  The variable @code{lpr-switches} has its standard meaning
-when @code{lpr-command} is not @code{""}.  If the variable
address@hidden has a string value, it is used as the value for the
address@hidden option to @code{lpr}, as on Unix.
address@hidden ps-print-buffer @r{(MS-DOS)}
address@hidden ps-spool-buffer @r{(MS-DOS)}
address@hidden ps-printer-name @r{(MS-DOS)}
address@hidden ps-lpr-command @r{(MS-DOS)}
address@hidden ps-lpr-switches @r{(MS-DOS)}
-  A parallel set of variables, @code{ps-lpr-command},
address@hidden, and @code{ps-printer-name} (@pxref{PostScript
-Variables}), defines how PostScript files should be printed.  These
-variables are used in the same way as the corresponding variables
-described above for non-PostScript printing.  Thus, the value of
address@hidden is used as the name of the device (or file) to
-which PostScript output is sent, just as @code{printer-name} is used for
-non-PostScript printing.  (There are two distinct sets of variables in
-case you have two printers attached to two different ports, and only one
-of them is a PostScript printer.)
-  The default value of the variable @code{ps-lpr-command} is @code{""},
-which causes PostScript output to be sent to the printer port specified
-by @code{ps-printer-name}, but @code{ps-lpr-command} can also be set to
-the name of a program which will accept PostScript files.  Thus, if you
-have a non-PostScript printer, you can set this variable to the name of
-a PostScript interpreter program (such as Ghostscript).  Any switches
-that need to be passed to the interpreter program are specified using
address@hidden  (If the value of @code{ps-printer-name} is a
-string, it will be added to the list of switches as the value for the
address@hidden option.  This is probably only useful if you are using
address@hidden, so when using an interpreter typically you would set
address@hidden to something other than a string so it is
-  For example, to use Ghostscript for printing on an Epson printer
-connected to the @samp{LPT2} port, put this in your @file{_emacs} file:
-(setq ps-printer-name t)  ; Ghostscript doesn't understand -P
-(setq ps-lpr-command "c:/gs/gs386")
-(setq ps-lpr-switches '("-q" "-dNOPAUSE"
-                       "-sDEVICE=epson"
-                       "-r240x72"
-                       "-sOutputFile=LPT2"
-                       "-Ic:/gs"))
address@hidden example
-(This assumes that Ghostscript is installed in the @file{"c:/gs"}
address@hidden dos-printer
address@hidden dos-ps-printer
-  For backwards compatibility, the value of @code{dos-printer}
-(@code{dos-ps-printer}), if it has a value, overrides the value of
address@hidden (@code{ps-printer-name}), on MS-DOS and MS-Windows
address@hidden MS-DOS and MULE
address@hidden International Support on MS-DOS
address@hidden international support @r{(MS-DOS)}
-  Emacs on MS-DOS supports the same international character sets as it
-does on GNU, Unix and other platforms (@pxref{International}), including
-coding systems for converting between the different character sets.
-However, due to incompatibilities between MS-DOS/MS-Windows and other systems,
-there are several DOS-specific aspects of this support that you should
-be aware of.  This section describes these aspects.
-  The description below is largely specific to the MS-DOS port of
-Emacs, especially where it talks about practical implications for
-Emacs users.  For other operating systems, see the @file{code-pages.el}
-package, which implements support for MS-DOS- and MS-Windows-specific
-encodings for all platforms other than MS-DOS.
address@hidden @kbd
address@hidden M-x dos-codepage-setup
-Set up Emacs display and coding systems as appropriate for the current
-DOS codepage.
address@hidden M-x codepage-setup
-Create a coding system for a certain DOS codepage.
address@hidden table
address@hidden codepage, MS-DOS
address@hidden DOS codepages
-  MS-DOS is designed to support one character set of 256 characters at
-any given time, but gives you a variety of character sets to choose
-from.  The alternative character sets are known as @dfn{DOS codepages}.
-Each codepage includes all 128 @acronym{ASCII} characters, but the other 128
-characters (codes 128 through 255) vary from one codepage to another.
-Each DOS codepage is identified by a 3-digit number, such as 850, 862,
-  In contrast to X, which lets you use several fonts at the same time,
-MS-DOS normally doesn't allow use of several codepages in a single
-session.  MS-DOS was designed to load a single codepage at system
-startup, and require you to reboot in order to change
address@hidden, one particular codepage is burnt into the
-display memory, while other codepages can be installed by modifying
-system configuration files, such as @file{CONFIG.SYS}, and rebooting.
-While there is third-party software that allows changing the codepage
-without rebooting, we describe here how a stock MS-DOS system
-behaves.}.  Much the same limitation applies when you run DOS
-executables on other systems such as MS-Windows.
address@hidden unibyte operation @r{(MS-DOS)}
-  If you invoke Emacs on MS-DOS with the @samp{--unibyte} option
-(@pxref{Initial Options}), Emacs does not perform any conversion of
address@hidden characters.  Instead, it reads and writes any address@hidden
-characters verbatim, and sends their 8-bit codes to the display
-verbatim.  Thus, unibyte Emacs on MS-DOS supports the current codepage,
-whatever it may be, but cannot even represent any other characters.
address@hidden dos-codepage
-  For multibyte operation on MS-DOS, Emacs needs to know which
-characters the chosen DOS codepage can display.  So it queries the
-system shortly after startup to get the chosen codepage number, and
-stores the number in the variable @code{dos-codepage}.  Some systems
-return the default value 437 for the current codepage, even though the
-actual codepage is different.  (This typically happens when you use the
-codepage built into the display hardware.)  You can specify a different
-codepage for Emacs to use by setting the variable @code{dos-codepage} in
-your init file.
address@hidden language environment, automatic selection on @r{MS-DOS}
-  Multibyte Emacs supports only certain DOS codepages: those which can
-display Far-Eastern scripts, like the Japanese codepage 932, and those
-that encode a single ISO 8859 character set.
-  The Far-Eastern codepages can directly display one of the MULE
-character sets for these countries, so Emacs simply sets up to use the
-appropriate terminal coding system that is supported by the codepage.
-The special features described in the rest of this section mostly
-pertain to codepages that encode ISO 8859 character sets.
-  For the codepages which correspond to one of the ISO character sets,
-Emacs knows the character set name based on the codepage number.  Emacs
-automatically creates a coding system to support reading and writing
-files that use the current codepage, and uses this coding system by
-default.  The name of this coding system is @address@hidden, where
address@hidden is the codepage address@hidden standard Emacs coding
-systems for ISO 8859 are not quite right for the purpose, because
-typically the DOS codepage does not match the standard ISO character
-codes.  For example, the letter @samp{@,{c}} (@samp{c} with cedilla) has
-code 231 in the standard Latin-1 character set, but the corresponding
-DOS codepage 850 uses code 135 for this glyph.}
address@hidden mode line @r{(MS-DOS)}
-  All the @address@hidden coding systems use the letter @samp{D} (for
-``DOS'') as their mode-line mnemonic.  Since both the terminal coding
-system and the default coding system for file I/O are set to the proper
address@hidden@var{nnn}} coding system at startup, it is normal for the mode
-line on MS-DOS to begin with @samp{-DD\-}.  @xref{Mode Line}.
-Far-Eastern DOS terminals do not use the @address@hidden coding
-systems, and thus their initial mode line looks like the Emacs default.
-  Since the codepage number also indicates which script you are using,
-Emacs automatically runs @code{set-language-environment} to select the
-language environment for that script (@pxref{Language Environments}).
-  If a buffer contains a character belonging to some other ISO 8859
-character set, not the one that the chosen DOS codepage supports, Emacs
-displays it using a sequence of @acronym{ASCII} characters.  For example, if 
-current codepage doesn't have a glyph for the letter @address@hidden (small
address@hidden with a grave accent), it is displayed as @address@hidden@}}, 
-the braces serve as a visual indication that this is a single character.
-(This may look awkward for some non-Latin characters, such as those from
-Greek or Hebrew alphabets, but it is still readable by a person who
-knows the language.)  Even though the character may occupy several
-columns on the screen, it is really still just a single character, and
-all Emacs commands treat it as one.
address@hidden IBM graphics characters (MS-DOS)
address@hidden box-drawing characters (MS-DOS)
address@hidden line-drawing characters (MS-DOS)
-  Not all characters in DOS codepages correspond to ISO 8859
-characters---some are used for other purposes, such as box-drawing
-characters and other graphics.  Emacs maps these characters to two
-special character sets called @code{eight-bit-control} and
address@hidden, and displays them as their IBM glyphs.
-However, you should be aware that other systems might display these
-characters differently, so you should avoid them in text that might be
-copied to a different operating system, or even to another DOS machine
-that uses a different codepage.
address@hidden dos-unsupported-character-glyph
-  Emacs supports many other characters sets aside from ISO 8859, but it
-cannot display them on MS-DOS.  So if one of these multibyte characters
-appears in a buffer, Emacs on MS-DOS displays them as specified by the
address@hidden variable; by default, this glyph
-is an empty triangle.  Use the @kbd{C-u C-x =} command to display the
-actual code and character set of such characters.  @xref{Position Info}.
address@hidden codepage-setup
-  By default, Emacs defines a coding system to support the current
-codepage.  To define a coding system for some other codepage (e.g., to
-visit a file written on a DOS machine in another country), use the
address@hidden codepage-setup} command.  It prompts for the 3-digit code of
-the codepage, with completion, then creates the coding system for the
-specified codepage.  You can then use the new coding system to read and
-write files, but you must specify it explicitly for the file command
-when you want to use it (@pxref{Text Coding}).
-  These coding systems are also useful for visiting a file encoded using
-a DOS codepage, using Emacs running on some other operating system.
address@hidden MS-Windows codepages
-  MS-Windows provides its own codepages, which are different from the
-DOS codepages for the same locale.  For example, DOS codepage 850
-supports the same character set as Windows codepage 1252; DOS codepage
-855 supports the same character set as Windows codepage 1251, etc.
-The MS-Windows version of Emacs uses the current codepage for display
-when invoked with the @samp{-nw} option.  Support for codepages in the
-Windows port of Emacs is part of the @file{code-pages.el} package.
address@hidden MS-DOS Processes
address@hidden Subprocesses on MS-DOS
address@hidden compilation under MS-DOS
address@hidden inferior processes under MS-DOS
address@hidden compile @r{(MS-DOS)}
address@hidden grep @r{(MS-DOS)}
-  Because MS-DOS is a single-process ``operating system,''
-asynchronous subprocesses are not available.  In particular, Shell
-mode and its variants do not work.  Most Emacs features that use
-asynchronous subprocesses also don't work on MS-DOS, including
-Shell mode and GUD.  When in doubt, try and see; commands that
-don't work output an error message saying that asynchronous processes
-aren't supported.
-  Compilation under Emacs with @kbd{M-x compile}, searching files with
address@hidden grep} and displaying differences between files with @kbd{M-x
-diff} do work, by running the inferior processes synchronously.  This
-means you cannot do any more editing until the inferior process
-  Spell checking also works, by means of special support for synchronous
-invocation of the @code{ispell} program.  This is slower than the
-asynchronous invocation on other platforms
-  Instead of the Shell mode, which doesn't work on MS-DOS, you can use
-the @kbd{M-x eshell} command.  This invokes the Eshell package that
-implements a Posix-like shell entirely in Emacs Lisp.
-  By contrast, Emacs compiled as a native Windows application
address@hidden support asynchronous subprocesses.  @xref{Windows
address@hidden printing under MS-DOS
-  Printing commands, such as @code{lpr-buffer} (@pxref{Printing}) and
address@hidden (@pxref{PostScript}), work in MS-DOS by sending
-the output to one of the printer ports.  @xref{MS-DOS Printing}.
-  When you run a subprocess synchronously on MS-DOS, make sure the
-program terminates and does not try to read keyboard input.  If the
-program does not terminate on its own, you will be unable to terminate
-it, because MS-DOS provides no general way to terminate a process.
-Pressing @kbd{C-c} or @address@hidden might sometimes help in these
-  Accessing files on other machines is not supported on MS-DOS.  Other
-network-oriented commands such as sending mail, Web browsing, remote
-login, etc., don't work either, unless network access is built into
-MS-DOS with some network redirector.
address@hidden directory listing on MS-DOS
address@hidden dired-listing-switches @r{(MS-DOS)}
-  Dired on MS-DOS uses the @code{ls-lisp} package where other
-platforms use the system @code{ls} command.  Therefore, Dired on
-MS-DOS supports only some of the possible options you can mention in
-the @code{dired-listing-switches} variable.  The options that work are
address@hidden, @samp{-a}, @samp{-c}, @samp{-i}, @samp{-r}, @samp{-S},
address@hidden, @samp{-t}, and @samp{-u}.
 @node Windows Processes
 @section Subprocesses on Windows 9X/ME and Windows NT/2K

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