FreeDOS/docs/config.txt

Title: Config.sys Options

Configuring your DOS system for use:
------------------------------------
When booting DOS, you will find it only supports a subset of
the devices available on many computers.  To support additional
devices and advanced features, device specific driver and
memory resident software most be loaded.  This allows the
kernel to be easily extended to support hardware not presently
available and take better advantage of installed hardware
without wasting resources on computers lacking it.  This
software is generally loaded during the kernel initialization
phase, with details describing what to load expressed in the
file CONFIG.SYS.  The FreeDOS kernel will first look for a
file named FDCONFIG.SYS, should it exist, it will will be used
instead of CONFIG.SYS; this allows the FreeDOS kernel to coexist
and be configured differently than another DOS kernel.  There
are additional options available to adjust other aspects of the
kernel's behaviour.  Note: some options listed below are FreeDOS
specific and will not work when using other/older DOS kernels.
Below is list of all documented FreeDOS config.sys supported
options; additional undocumented options may exist but are not
meant for normal usage.


BREAK
Usage:  break=on|off
Set extended Control-C/Control-Break checking to on [default] or off.
When set to on, the kernel will perform the check (and invoke current
handler if pressed) prior to most int 21h calls.  When set to off,
the kernel only performs the check on I/O calls using standard streams.
e.g.  break=off

BUFFERS
BUFFERSHIGH
Usage:  buffers=nn[,n] where nn is in range 1-99 & n is in range 1-8
Memory buffers used by the kernel; primary[,secondary]
The secondary buffer option is available for compatibility with
other DOS kernels, but is ignored by the FreeDOS kernel.
e.g.  buffers=20

COUNTRY
Usage:  country=nnn[,[mmm][,[d:][path]file]]
Only limited country=nnn support is presently available.
Enables/sets international features of DOS
nnn is country code (001==US)
mmm is code page (437 is default, 850 is updated form, 1252 for Windows)
[drive][path]file specifies file with country specific data
e.g.  country=001,850,C:\FDOS\BIN\COUNTRY.SYS

DEVICE
Usage:  device=[d:][path]file [options]
Load the device driver specified by d:path\file (into conventional
[low 640KB] memory).  The options are for the driver itself; refer
to documentation that came with your particular device for supported
options and their usage.
e.g.  device=himem.sys

DEVICEHIGH
Usage:  devicehigh=[d:][path]file [options]
This is just like device= statement, except it attempts to load
the device driver into high memory first (failing that it should
load it in conventional memory).  
Note: The order you load devices may have a large impact on amount
of free memory available.  In general try to load large (in memory
usage) programs into high memory first.
Important: You should have a high memory manager such as FDXMS or
Himem installed (prior device=FDXMS.SYS or device=HIMEM.SYS) before
using this option.
e.g.  devicehigh=atapicdd.sys /D:FDCD0001

DOS
Usage:  dos=high|low,umb|noumb
Indicates whether the kernel should try to load itself into
high memory or only conventional (low), and whether to link
upper memory blocks in with normal memory or not.  
Note: only one set need be given, ie dos=high and dos=noumb are ok.
Important: if you specify dos=high[,umb|noumb] then you must also
load a high memory manager (first), ie FDXMS or HIMEM
e.g.  dos=high,umb
or    dos=low,noumb

DOSDATA
Usage:  dosdata=umb
Try to load kernel data into Upper Memory Blocks; effectively
same as using the <name>HIGH variant of kernel parameters,
such as fileshigh, lastdrivehigh, and stackshigh (does not
effect drivers loaded using device= or install=).
e.g.  dosdata=umb

ECHO
Usage:  ECHO Message to be displayed to user.
ECHO displays (echos) its arguments to the console during
config.sys processing when device drivers are loaded (when
DEVICE= lines are executed).
e.g.  
      ECHO loading driver 1
      device=Driver1.sys
      ECHO driver1 successfully loaded

EECHO
Usage:  EECHO Message with ANSI Escape Sequence
EECHO allows for echo-ing ANSI Escape Sequences
(redefines keyboard input for example).  Use a dollar sign ($)
to represent the ANSI Escape character.  Note: requires an
ansi driver loaded prior to use.

FCBS
Usage:  fcbs=nnn
where nnn is in range 1-255
Sets the number of File Control Blocks to reserve room for.
As file control blocks have been replaced by file handles
(see files) most applications will not need this value adjusted.
e.g.  fcbs=4

FILES
FILESHIGH
Usage:  files=nnn 
where nnn is in range 8-255 (default 8)
Specifies how many files allowed open at once (reserves
memory necessary to support opening this many files).
Note: there are other restrictions, so a given program
       may not be able to actually open this many
A good number is 20, though some programs suggest/require
30, 40, or even 255
e.g.  files=20

INSTALL
INSTALLHIGH
Usage:  install=[d:][path]file [options]
Load the program specified by d:path\file.  Generally used to
load TSR (terminate and stay resident) programs with a minimal
environment block.  The options are for the program itself; refer
to documentation that came with your particular software for
supported options and usage.
e.g.  install=nansi.com

LASTDRIVE
LASTDRIVEHIGH
Usage:  lastdrive=x 
where x is last drive letter available for use; A-Z
e.g. lastdrive=z

NUMLOCK
Usage:  numlock=on|off
Set the keyboard number lock to on or off.
e.g.  numlock=off

REM
Usage:  rem Your remarks!
This provides the ability to place comments within the configuration
file.  The text following the rem until the end of the line is
reached are ignored.  This may also be used to temporarily disable
loading a particular device or other option.

SCREEN
Usage:  screen=xx
Switches into videomode xxx  (INT10/11xx/000)
where xx should be 0x11 for 28 lines or 0x12 for 43/50 (EGA/VGA) lines

SET
Usage:  set ENVVAR=value
Sets the environment variable to provided value.
e.g.  set HOME=C:\home\me

SHELL
SHELLHIGH
Usage:  shell=[d:][path]file [options]
Indicates the shell to use; often used to alter COMMAND.COM's behavior.
Note: it is command.com that processes AUTOEXEC.BAT; by using the
shell option, you can get command.com to process a differently named
file (such as FDAUTO.BAT for coexisting with another DOS using different
configuration options) or run a completely different command interpreter
such as 4DOS or a (unix) sh variant.
e.g.  shell=C:\COMMAND.COM /E:256 /P

STACKS
STACKSHIGH
Usage:  stacks=nn,nnn
where nn is in range 0,8-64 and nnn is in range 32-512
Changes number of stacks available
nn is number of different stacks and nnn is size in bytes of each one
e.g.  stacks=16,256

SWITCHAR
Usage:  switchar=c
Sets the default switchar to character c.  Where c is a single character
that is used to indicate a command line parameter is an option switch.
The default is a forward slash (/).  Note: This simply sets the value
returned by a get switchar query, it will not effect programs that use
hardcoded switch characters.
e.g.  switchar=-

SWITCHES
Usage: switches=/E[:xxx] /F /K /N /W
Adjusts boot time processing behaviour.
/F skips the delay checking for F5/F8 keystroke before processing config.sys
   [equivalent to setting kernel config option skipconfigseconds = 0]
/N disables F5/F8 support [equivalent to kernel config skipconfigseconds = -1]
(note: with /F a well timed F5/F8 still works, whereas /N completely disables)
/K forces treating of keyboard as 86 key keyboard
/E enables moving of EBDA (Extended BIOS Data Area), optionally a size in KB
   may be specified [xxx, in range of 48-1024]
/W disables Windows 3.0 from loading WINA20.386 from the root directory (used
   when \WINA20.386 is moved into a subdirectory, a device line with proper
   path must be added to Microsoft (R) Windows' SYSTEM.INI [386Enhanced]
   section.)  ---  Unsupported, though may be ignored for compatibility.

VERSION
Usage:  version=x.y
FreeDOS specific command to specify what DOS version to report.
e.g.  version=6.2



Advanced - FreeDOS specific CONFIG.SYS menu processing:
-------------------------------------------------------

normal
	FILES=20
	DEVICE=MyNetWorkDriver.sys

'?' - ALWAYS ask if a single line shall be executed
	FILES=20
	?DEVICE=MyNetWorkDriver.sys


'!' - NEVER ask if a single line shall be executed, even if single stepping
	!FILES=20
	!DOS=HIGH,UMB
	!BUFFERS=30
	DEVICE=MyNetWorkDriver.sys


configuration management - you may compose several configurations,
using following special commands:

MENU
MENU  select your configuration
MENU
MENU  use (0) for basic configuration
MENU  use (1) for CDROM operation
MENU  use (2) for NETWORK configuration
MENU
MENUDEFAULT=0,1				( configuration 0, wait 1 second)


1?  rem CDROM
1?  device=CDROM.SYS

2?  rem NETWORK
2?  device=MyNetworkDriver.SYS


Although this is different than MSDOS menuing possibilities, it 
allows for selecting from multiple options during bootup while
remaining simple.  It, however, does not allow for multi-level
menuing based configuration schemes.


It's also possible to combine menu options, to avoid writing thing every 
time again.
constructions like 0?devicehigh?=cdrom.sys are also possible
("if menu option 0 chosen, ask if you want to load this driver")

the selected configuration can be determined in AUTOEXEC.BAT in the
environment variable CONFIG like

        if %CONFIG% == 0 echo configuration 0 selected

however, if you have no MENUs in config.sys, then %config% has no value,
thus resulting in "IF == 0 echo configuration 0 selected."
(which causes syntax errors as there's nothing on the left side of == )

That's why you better use something like:
if [%config%]==[0] echo configuration 0 selected.        -or-
if "%config%"=="0" echo configuration 0 selected.

then if there is no menu you have: "IF []==[0] echo configuration 0 selected."
(which will of course output nothing)

thus my config.sys now looks like


!files=20
!dos=high,umb
!break=off
!buffers=30
!screen=0x12
!lastdrive=z
!shellhigh=a:\command.com /p /e:512 /MSG

MENU
MENU 0 - SoftIce+HIMEM+Network (default)
MENU 1 - SoftIce+HIMEM
MENU 2 -         HIMEM+EMM386
MENU
MENUDEFAULT=0,0


01? DEVICE=C:\NUMEGA\S-ICE.EXE /TRA 3000 /SYM 400
012?DEVICE=himem.exe
01? DEVICE=UMBPCI.SYS
2?  DEVICE=EMM386.EXE NOEMS

0?device=c:\ntclient\ifshlp.sys

DEVICE=ATAPICDD.SYS /D:MSCD000

Full Screen Menus (thanks to Rune Espeseth)

Use MENUCOLOR=foreground[,background] to obtain a full screen menu
where you can use the arrow keys. Example (note that box drawing
characters are used that look strange in other character sets):

REM *** This is the FreeDos Config.sys ***
REM *** executed before autoexec.bat   ***

REM *** Set white foreground, red background ***
menucolor=7,4

files=20
buffers=20

REM *** The Menu ***
MENU
MENU  <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͻ
MENU  <20> My Menu - FreeDOS rules!                              <20>
MENU  <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>͹
MENU  <20>                                                       <20>
MENU  <20>   1. Test with border                                 <20>
MENU  <20>                                                       <20>
MENU  <20>   2. Another test...                                  <20>
MENU  <20>                                                       <20>
MENU  <20>   3. Third choice                                     <20>
MENU  <20>                                                       <20>
MENU  <20>   4. Fourth choice.                                   <20>
MENU  <20>                                                       <20>
MENU  <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͼ
MENU

MENUDEFAULT=1,10		( configuration 1, wait 10 seconds)

1?  REM 1st choice
1?  ECHO You selected menu #1 

2?  REM 2nd choice
2?  ECHO You selected menu #2

3?  REM 3rd choice
3?  ECHO You selected menu #3

4?  REM 4th choice
4?  ECHO You selected menu #4


2002-11-28 - Tom Ehlert
2003-07-15 - Bernd Blaauw
2003-09-18 - Bart Oldeman
2004-07-24 - Jeremy Davis