readme.txt for EMM386/HIMEM

    ***********************************************************
    *THIS IS FREE SOFTWARE WITH ABSOLUTELY NO WARRANTY        *
    *WHATSOEVER, WHICH YOU MAY USE COMPLETELY AT YOUR OWN RISK*
    *                                                         *
    *IF IT WORKS FOR YOU - FINE.                              *
    *                                                         *
    *IF IT DOESN'T - STOP USING, BUT DON'T COMPLAIN.          *
    *                                                         *
    *IF YOU SEND BUG REPORT'S, SEND DETAILS                   *
    *I WONT'T EVEN LOOK AT BUG REPORTS LIKE                   *
    *  'your EMM386 makes problems. can you help?'            *
    *                                                         *
    * FIXES WELCOME                                           *
    ***********************************************************

    EMM386/HIMEM is released under the GNU GENERAL PUBLIC LICENSE, 
    see the file DOCS\LICENSE.TXT for the full text. 
    
    In addition, the original authors copyrights must remain intact;


 ********************************************************************
 ****** this release requires FreeDOS kernel version >= ke2026 ******
 ********************************************************************


What it shall do:

    HIMEM.EXE  replaces MSDOS HIMEM.SYS,
    EMM386.EXE replaces MSDOS EMM386.EXE


 ****************  Why use EMM386   ****************

if you need Upper memory and your PC is not recognized by 
    UMBPCI

if you want enhanced (EMS) memory

 **************** Why NOT use EMM386 ***************
 
if you want to run protected mode (VCPI/DPMI) programs,
you can't run EMM386. to be done - much later.

Programs doing a LOT of IN/OUT may run slower in a protected
mode environment like EMM386


 ******  How to use it *******************************
 


change CONFIG.SYS like

    files=20
    buffers=30
    lastdrive=z
    break=off
    
>>> dos=high,umb
>>> device=HIMEM.EXE        
>>> device=EMM386.exe NOEMS 
>>> shellHIGH=c:\command.com /p /e:512

both HIMEM and EMM386 require PC's >= 80386 to run.

            
*******************************************************



COMMANDLINE switches implemented

    use EMM386.EXE from commandline - it will tell you:
    
         NOEMS      - disable EMS completely (default=enable)
         VDS        - enable  VDS current status is experimental
         FRAME=D000 - select wanted pageframe(default=highest possible)
         EMM=20000  - 20000 KB EMS memory wanted(default=8MB)
         X=D000-D800 - no make memory mapped devices work

         I=A000-AFFF - IF YOU REALLY KNOW WHAT YOU DO (VGA graphics)
         I=B000-B7FF - IF YOU REALLY KNOW WHAT YOU DO (Hercules)
         I=BC00-BFFF - IF YOU REALLY KNOW WHAT YOU DO (VGA upper text)
                            see WARNING below

         /VERBOSE    - give some more details about found devices, 
                       mapped UMB's,...l


    EMM386 allocates fixed amount of whatsneeded (from HIMEM.EXE)
        needed internally ca. 96 KB for pagetables, high code,...
        64K for DMA handling ( no idea if that works though)
        additionally enough memory to map UMB's (16..160KB)
    
        + tries to allocate the wanted EMS memory (default=8MB) 
        more to be used as EMS memory

    WARNING:
        in theory, its possible to use upper memory at 
        A000..AFFF (VGA graphics) and
        B000..B7FF (hercules adapter)
        
        
        however some programs (or the BIOS INT 10 functions)
        seem to write _sometimes_ into this area,
        so operating with this memory area 
        
            IS HIGHLY DISRECOMMENDED to use A000-B7FF
            
        use it at your own risk only            


*********************   known BUGS ***************
EMM386 seems to run stable.
VDS support is only experimental

no VCPI/DPMS/DOS32 functionality
    none at all - not even thought about that

*********************   troubleshooting ***************


if you have problems 
add /VERBOSE to EMM386 commandline, will give some details
about XMS memory, UMB memory, blocks mapped,...

make sure you have kernel >=2026

1'st) start with following CONFIG.SYS
	!files=20
	!anydos=1
	!break=off
	!buffers=30
	!screen=0x12
	!lastdrive=z
	!stacks=0,0
	!dos=high,umb
	!shellhigh=a:\command.com /P /E:512 /MSG
	
	
	DEVICE=\freedos\himem.exe
	DEVICE=\freedos\emm386.exe NOEMS /VERBOSE

	rem - if you want CD:
	rem DEVICE=\freedos\CDROM.SYS /D:MSCD000

2'nd) add one driver after the other, until you find
    the one, that causes trouble.
    try to load it high (deviceHIGH=),
    then to load low (device=),
    then try to load BEFORE EMM386.
    please report any *positive* results, so I can
    add them here.
    
3'rd) you are out of luck. sorry.       
    

*********************   known incompatibilities ***************

FDXMS08
    uses priviledged instructions and is not supported

FDXMS09
    has a bug and is not supported
    please use HIMEM.EXE, which is 400 byte smaller as well.

***********************************************************



tom ehlert (tom.ehlert@ginko.de) 2002-04-03