Undocumented Windows 95

[os2fan2]

I've been playing with Undocumented Win9x config.sys commands.

• DOS=SINGLE
• LOGO n

DOS=SINGLE loads windows normally, including win.com. But when this comes, instead of loading the GUI, it just gives a prompt 'You know you are in DOS, To load windows normally, press "enter", to continue, press "escape".

LOGO 1 tells windows to load the logo even in DOS mode. Normally, booting into DOS does not do this.

You can get around the Win.com prompt, by renaming win.com to win.exe, and putting something harmless at win.com, such as drives.com. So it boots normally, and gives a harmless message listing available drives.

This is a generic install of Windows 95 into C:\FENSTER. The DOS junk has been copied into MSDOS7. We've got general utilities in C:\USE and Norton Commander 5.51 is in NC55, and NCW in NC201,



This is the resulting CONFIG.SYS

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[menu]
menuitem Win95,Windows
menuitem MSDOS7,MSDOS7

[Win95]

[msdos7]
dos=high,noauto,single
device=c:\msdos7\himem.sys
files 60
logo 1
shell c:\msdos7\command.com c:\msdos7 /p
devicehigh=c:\msdos7\ramdrive.sys 1024 /e

[common]
DEVICE=c:\FENSTER\VMADD\CDROM.SYS /D:MSCD0000
LASTDRIVE=Z

AUTOEXEC.BAT Note because we don't use WIN.COM at the end of the batch, we load it in the batch as WIN.EXE

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@echo off
echo %config%
goto %config%
c:\use\doskey -i

:win95
cd c:\fenster
c:\FENSTER\VMADD\SYSINI.EXE
c:\fenster\win.exe
goto :eof

:msdos7
c:\use\keyb uk
path c:\msdos7;c:\use;c:\nc55;%path%
vmmouse.com
mscdex /d:mscd0000
set vdisk=C:
c:\use\setvdisk
echo The ramdrive is in %vdisk%
goto :eof

:eof

setvdisk.com is a utility that finds a drive with ramdrive, and modifies the environment variable vdisk=c: to vdisk= the drive it finds. It does this by looking for vdisk=?? and pokes the variable into ??.

[Darkstar]

Offtopic Comment

Did you really call your "Windows" directory "FENSTER"?

[os2fan2]

It has a variety of names: Fenster is german for Winndows, but English has 'defenestrate' for a Czech form of removing politicians by tossing them out the window. My main windows is in H:\FENSTER

Another name is LEGACY, so you can talk about Windows software as 'legacy software'. It was used of Windows 95 on the 486.

[jimmsta]

that's really neat. Does this get you into a 32-bit dos session or just a command prompt?

[os2fan2]

What ye get with DOS=SINGLE is the same as 'reboot to dos' mode or shortcut. It still loads windows, but when it sees win.com., it gives 'did you know you are in MS-DOS mode, press enter to reboot or escape to continue. Here we are in the Win95 directory, and i type 'win'. This is drives recopied.

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C:\FENSTER>win                                                                 
  Valid drives are A: B: C: D: E: F: G: L: P:

C:\FENSTER>win.exe                                                             

You are currently running in MS-DOS mode. Do you want to                       
return to normal mode, to run Windows applications again [Enter=Y,Esc=N]?N     

You are still running in MS-DOS mode. To return to normal               
mode, exit the application you are running, or type WIN again. 

Typing win.exe (renamed win.com) gives you the prompt as above. It is little wonder i did this extra hack, since Win95 runs %winbootdir%\win.com after DOS has loaded.

This is the DOS environment.

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CONFIG=MSDOS7   ;  set by config.sys
TMP=C:\FENSTER\TEMP    ;  set by IO.SYS as %winbootdir%\temp
TEMP=C:\FENSTER\TEMP  ;  set by IO.SYS as %winbootdir%\temp
PROMPT=$p$g    ; set by IO.SYS as $P$G
winbootdir=C:\FENSTER    ;  From \MSDOS.SYS [Paths] Winbootdir=
COMSPEC=C:\MSDOS7\COMMAND.COM   \ Set by SHELL=
PATH=C:\MSDOS7;C:\USE;C:\NC55;C:\FENSTER;C:\FENSTER\COMMAND  C:\fenster ... is embedded path
VDISK=F:    ;  set by SETVDISK.COM, overwriting VDISK=C:
CDROM=G:    ;  set by http://www.robvanderwoude.com/amb_cdrom.php
CMDLINE=win.exe    ;  This is the win loader WIN.COM.                         

CONFIG comes from config.sys, COMSPEC from command.com, the PATH is C:\....N55;%PATH%, VDISK and CDROM are set by some sub 512byte utilities, that actually set the setting.

Note winbootdir is there, but not windir. Path is set by IO to %winbootdir%;%winbootdir%\COMMAND.

[os2fan2]

So let's be clear about the different ways of loading DOS from Windows.

1. Bootgui=0 (MSDOS.SYS) or from the IO.SYS menu (Normal, logged, etc)
2. DOS=SINGLE in config.sys
3. From 'reboot into DOS mode'
4. From a desktop shortcut.
5. Winstart (ie a command.com before windows is loaded).

You can start Windows from 1. Exiting from 5 loads windows.
4 creates a config.sys that starts DOS=SINGLE and ends with WIN /WX

[os2fan2]

The main problem in running DOS=SINGLE, rather than BootGUI=0, and loading win.com as required, is that the latter choice gives you room to load windows anyway, and that it gives you more memory. Running DOS=SINGLE and then specifying a shell is equivalent to starting command.com inside a shell program: you get command.com, win.com, and then another command.com loaded into memory. Even if win.com is just drives.com renamed!

So if you want a windows 95 / DOS session as separate boot menus, using DOS=SINGLE is best avoided, and use BootGUI=0 and run LOGO=1 in config.sys gives far better options.