DOS tips for running (older versions, e.g 3.40, of) BAHN

** This article is probably of very little relevance, if any, for
** running current versions of BAHN.  It has only been left here
** as a placeholder, in case I need to refer back to it later.

One of the annoying things about earlier versions of BAHN was that it
only used the DOS conventional memory area. Your normal PC setup
probably has lots of device drivers and TSR's loaded: with mine, for
example, although I make as much use as possible of the HMA and UMBs, it
still has too much loaded into its 640K addressing space to be able to
handle the larger BAHN datasets.

BAHN3.58 removes this restriction, so it will probably not be necessary
to use the following advice any more. However, it's sometimes needed for
DOS-based programs, so it seemed a pity to throw it away...

                            o O o

Here are some suggestions to get around this, without too much distress.
It is written from the point of view of DOS 5, but presumably can be
applied with similar effect in newer versions.

You can, obviously, create an independent DOS system on a diskette and
boot from that, but unless you take some special action, this system
will look for its COMMAND.COM and DOS commands on the diskette, which
can be a nuisance because the diskette is so much slower than the hard
disk. However, provided that the version of DOS on the diskette is the
same one that you have on your hard disk, you can set things up so that
the diskette is only used for booting up and getting CONFIG.SYS and
AUTOEXEC.BAT, and then for the rest of the session it uses COMMAND.COM
and the DOS commands from your hard disk.

To summarise, then, for your normal environment you will boot from hard
disk and nothing changes; for max memory to run BAHN you will boot from
a special diskette, which you have created by FORMAT A: /S and with
special CONFIG.SYS.and AUTOEXEC.BAT which we're going to discuss next.
Once you have booted, you will be getting your DOS commands etc. from
your hard disk as usual.

I'm assuming that you do have some extended memory, and that you won't
need to simulate expanded memory (which you won't, if you only plan to
run BAHN and ordinary DOS things in this mode). I'm also assuming you
can use EMM386, since that comes with DOS. There are some more
"intelligent" memory managers, but there's no guarantee you have access
to one, so I won't assume you have one.

Here's some points to bear in mind.

o With a VGA card you will probably find that memory from B000-B7FF
  is available.  You can tell EMM386 to use it.  
o Since you aren't going to simulate expanded memory, you won't
  need a page frame.  So memory from E000-EFFF is available too.

  (But you won't be able to run MS Windows if you grab these areas.
  You get no advantage running BAHN under Windows, so I assume you
  don't mind that.  Leave these area(s) alone if you do in fact
  intend to run Windows.)

o If you load DOS high, the book says that the BUFFERS will also be
  allocated high.  Well, yes and no.  If I set BUFFERS to 10 they are
  indeed allocated high, but if I set larger values then they get
  allocated in conventional memory, which makes a significant
  difference when you are trying to get every last byte.

o Obviously, you will want to use devicehigh and loadhigh for 
  everything that can work that way.

So, here's some models on which you could base your special config.sys
and autoexec.bat on your special diskette. Adjust the files according to
the name of the directory where you keep your DOS stuff, and according
to the ANSI driver, mouse driver, country setting etc. that you use.

A:\CONFIG.SYS :-
                                            
device=C:\DOS\HIMEM.SYS
device=C:\DOS\EMM386.EXE noems /i=b000-b7ff /i=e000-efff
DOS=HIGH,UMB
shell=c:\dos\command.com c:\dos /p/e:256
devicehigh=C:\DOS\SETVER.EXE                 assumes your DOS is in C:\DOS                            
devicehigh=c:\dos\nansi.sys                   
devicehigh=C:\DOS\DISPLAY.SYS CON=(EGA,437,3)
COUNTRY=044,,C:\DOS\COUNTRY.SYS             
FILES=20
BUFFERS=10
STACKS=0,0
LASTDRIVE=D

A:\AUTOEXEC.BAT :-

@ECHO OFF
SET TZ=GMT0BST
PROMPT $e[31;44;1m$p$g$e[33;44;1m
PATH C:\;C:\DOS
SET TEMP=C:\TEMP
lh C:\DOS\SMARTDRV.EXE 768 C+
lh KEYB UK,,C:\DOS\KEYBOARD.SYS
lh C:\MMOUSE\MMOUSE.COM /A4 >NUL
lh C:\DOS\DOSKEY
lh C:\DOS\NLSFUNC
C:

This specific setup leaves me 634,208 bytes for DOS programs, according
to the MEM command. There still seems to be a fair amound of UMB space
free, so there should be room for other TSRs that can be loaded high.

Hope this helps.