~Today's Top DOS Tip

Using multiple configurations on your system  -  By Simon Burrows



~`Introduction
~`

`Since the  arrival of  more and  more flash games, bigger and more
`powerful spreadsheets,  and more  system-hungry  C.A.D.  programs,
`organising your  system to  give the right memory-configuration to
`run all  these things  can be  an unwanted  hassle. Sometimes  the
`results of  this can  be disastrous,  with a great pile of boot-up
`disks, each of which used to load a different configuration so all
`your different  software will perform.  However, this doesn't have
`to be  the story!   Included  in MS-DOS  6.x, is a feature used to
`have multiple configurations all listed in your two CONFIG.SYS and
`AUTOEXEC.BAT programs.   Each time you power-on your computer, you
`are presented  with  a  menu  from  which  you  can  select  which
`configuration you wish to be used in this session.


~`Method and Examples
~`

`Of course,  the  first  step  is  to  decide  how  many  different
`configurations you  are going  to want  to use,  and what each one
`will have  in it.  When you have done this, you need to decide two
`names for  each one.   The  first name is a simple reference which
`only your  computer will  use  (such as 'extended' or 'expanded').
`The second is a more detailed name which will be used as the title
`for the memory-configuration on the menu.

`For example,  if  you  have  one  configuration  to  load  maximum
`extended memory,  and one  to load  maximum expanded  memory,  you
`might use the following names :-



~`Simple Name      Main name for menu
~`ĳ
~`EXTENDED        Use HIMEM.SYS to enable max. Extended Memory
~`EXPANDED        Use EMM386.EXE to enable max. Expanded Memory



`When you  have decided all this, edit your CONFIG.SYS, and type in
`each of  these configurations,  one at a time, with a two-line gap
`in between  each one.   When that's down on the screen, put a line
`above each  configuration with  the simple  name for the config in
`square brackets.   For  example,  a  two-configuration  CONFIG.SYS
`might look like this :-



~`[EXTENDED]
`DEVICE=C:\DOS\HIMEM.SYS
`DOS=HIGH,UMB
`BUFFERS=20
`FILES=20

~`[EXPANDED]
`DEVICE=C:\DOS\HIMEM.SYS
`DOS=HIGH
`DEVICE=C:\DOS\EMM386.EXE 1024
`BUFFERS=20
`FILES=30



`Now you  are ready  to add the lines at the top of this CONFIG.SYS
`file to  tell your  PC that you want to have a menu displayed each
`item you  boot-up your  PC.   To do  this, the  first line  of the
`CONFIG.SYS must read '[MENU]'.  After this, you will need one line
`for each  configuration starting  with 'MENUITEM=', then the short
`name for the config, then a comma followed by your main name.

`If we  add these  lines to  our example CONFIG.SYS, we now get the
`following :-



~`[MENU]
`MENUITEM=EXTENDED, Use HIMEM.SYS to enable max. Extended Memory
`MENUITEM=EXPANDED, Use EMM386.EXE to enable max. Expanded Memory

~`[EXTENDED]
`DEVICE=C:\DOS\HIMEM.SYS
`DOS=HIGH,UMB
`BUFFERS=20
`FILES=20

~`[EXPANDED]
`DEVICE=C:\DOS\HIMEM.SYS
`DOS=HIGH
`DEVICE=C:\DOS\EMM386.EXE 1024
`BUFFERS=20
`FILES=30



`Once this  is down,  it could  be argued  that you  have  finished
`editing this  file.   However, what happens if you have some lines
`which appear  in all  these memory configurations?  If this is the
`case, use  an extra  configuration called '[COMMON]' which has all
`these repeated lines in it.  So long as this is called '[COMMON]',
`your computer  will carry out all the lines in here as well as the
`ones in  the specialist  configuration selected  from the  Startup
`Menu.  For example, our CONFIG.SYS may look like this :-



~`[MENU]
`MENUITEM=EXTENDED, Use HIMEM.SYS to enable max. Extended Memory
`MENUITEM=EXPANDED, Use EMM386.EXE to enable max. Expanded Memory

~`[COMMON]
`DEVICE=C:\DOS\HIMEM.SYS
`BUFFERS=20

~`[EXTENDED]
`DOS=HIGH,UMB
`FILES=20

~`[EXPANDED]
`DOS=HIGH
`DEVICE=C:\DOS\EMM386.EXE 1024
`FILES=30



`That's the  CONFIG.SYS file  finished.   Now we  need to edit your
`AUTOEXEC.BAT file  so this  is split  into all  the configurations
`needed.   To do this, we split the AUTOEXEC.BAT in the same way by
`having different  sections for  different configuration.  However,
`instead of  each one  starting by the name of the configuration in
`square brackets, we instead start the line with a colon.

`At the  end of  each section,  we also  need a  line telling  your
`computer to  skip to  the end  of the  file so it doesn't load any
`other lines.  This is done by saying 'GOTO END' at the end of each
`configuration, then  having an  empty section  called 'END' at the
`bottom of  the file.  We also need a line at the start which tells
`your computer  to go to the section selected from your menu.  This
`line reads 'GOTO %CONFIG%'.

`All this  put together, the AUTOEXEC.BAT for the CONFIG.SYS above,
`may look as follows :-



`GOTO %CONFIG%

~`:EXTENDED
`C:\DOS\MOUSE.COM
`C:\WINDOWS\SMARTDRV.EXE 1024
`PATH=C:\DOS;C:\;C:\WINDOWS
`PROMPT $P$G
`GOTO END

~`:EXPANDED
`C:\DOS\MOUSE.COM
`PATH=C:\DOS;C:\;C:\WINDOWS
`PROMPT $T$D $P$G
`GOTO END

~`:END



`There's just  one problem,  though!   Instead of  having a section
`called ':COMMON'  to put  in lines  which are  the  same  in  each
`configuration   (like in the CONFIG.SYS file), you need to add the
`lines which  would into  such a section before the 'GOTO %CONFIG%'
`line.  With this included, out AUTOEXEC.BAT file ends thus :-



`PATH=C:\DOS;C:\;C:\WINDOWS
`C:\DOS\MOUSE.COM
`GOTO %CONFIG%

~`:EXTENDED
`C:\WINDOWS\SMARTDRV.EXE 1024
`PROMPT $P$G
`GOTO END

~`:EXPANDED
`PATH=C:\DOS;C:\;C:\WINDOWS
`PROMPT $T$D $P$G
`GOTO END:

~:END



`If you now save these two files  (AUTOEXEC.BAT and CONFIG.SYS) and
`reeboot your  machine, you should find yourself with a nice start-
`up menu looking rather like this :-



~`MS-DOS 6.x Startup Menu
~`

~`1. Extended
~`2. Expanded

~`Enter a choice:_



Well there it is....   Have a nice day....



`       
~`       Simon Burrows
`       


