Mail Archives: opendos/2001/11/21/00:13:49
On 2001-11-19, "Uncle Slacky" wrote:
> Using some spare memory modules I have increased the memory of my old
> 16MHz 286 laptop to 5Mb. What is the best way to go about making the
> best use of this (i.e. freeing up as much lower mem as possible). I've
> installed DRDOS 7.03 but HIMEM didn't like the memory setup I have.
Could you be a bit more specific about the problem, please? Does
HIMEM.SYS give you an error message, does it hang, doesn´t it find
the memory, doesn´t it support your chipset?
What brand is the 286? If possible, I would be interested in the
mainboard model and - very important - the manufacturer of the
ROM-BIOS and the version. This should be displayed at startup or
could be leaked with the usual bunch of system info tools like
Quarterdeck´s MFT, Microsoft´s MSD, Norton SI, CONFIG, or DEBUG.
> I solved this by using HIMEM from MS-DOS 6.22. I've also created a 2Mb
> virtual disk (in order to run Arachne etc.) Is there anything else I can
> do to free up memory?
On a 286 with limited memory you will probably want to make maximum
use of your memory. I suggest to replace VDISK.SYS or RAMDRIVE.SYS
with TDSK.EXE, a highly optimized resizable RAM-disk driver, so you
can control the size of the disk at runtime. Also, it´s much faster
than the drivers shipped with DOS. You can find TDSK 2.42 (still
BETA, but very stable!) at
ftp://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/dos/ramdisk/
(Feature suggestions and reports to me, please. I already have
further enhanced issues in my queue... ;-)
In regard how to optimze memory on a 286, if your 286 has a chipset
which supports mapping in memory between C800h-EFFFh I suggest to
enable this feature (usually in the ROM-BIOS setup), as you can
load high some of your drivers then. It might also be useful to get
the DR-DOS HIMEM.SYS running on your system because if you have
one of the supported chipsets it may give you access to UMB
memory through the chipset.
In any way, it is important to run an XMS manager of either brand,
because it provides you the services to use XMS and the HMA.
Don´t forget to add DOS=HIGH (and optiotianlly DOS=HIGH,UMB if you
have UMBs) into your [D]CONFIG.SYS file, so the DOS BIOS, BDOS,
and some DOS data structures like BUFFERS will move up there.
You can also load KEYB, NLSFUNC, SHARE, and the resident part
of COMMAND.COM into the HMA. The first three should attempt to
do this by themselves, but you can force them to load there
with the /MH option. COMMAND.COM *needs* the /MH switch in
the [D]CONFIG.SYS SHELL= statement to load high, otherwise it
will remain in low memory. For example:
SHELL=c:\drdos\command.com c:\drdos\ /E:512 /MH /P:autoexec.bat
You should also load DPMS.EXE so that all the DPMS clients can
load and run in Protected Mode. DPMS clients shipping with DR-DOS
are NWCACHE (most useful for performance reasons, in particular
with delayed writes /DELAY=5000 /FLUSH=ON), DELWATCH (file deletion
tracking), NWCDEX (CDROM support extension, however, if you have EMS
memory as well, you can save more memory by using EMS for NWCDEX),
Stacker 3.xx (drive compression in background to almost double the
available free space on your harddisk, still fast enough on a 286 -
mind, that those old hardisk are so slow that the saved time to write
out the compressed data to disk might well outweight the CPU overhead
for the compression, so this may even make things faster if your
harddisk is slow and the CPU is not), Personal NetWare SERVER (slow,
but works on a 286 ;-). Other software supporting DPMS are some issues
of SuperStor & Super PC-Kwik, LONGNAME (for LFN support, not very
useful on a 286, though ;-), Award´s CARDWARE, IBM PC DOS 7+
Stacker 4, etc.
So, you can still have a reasonable well-configured system and much
free conventional memory left on a 286 to run your applications.
> BTW I have got hold of PCDOS2000 - would this offer any benefits
> over DRDOS? I understand it uses less lower memory than MSDOS 6.22,
> but I haven;'t run a comparison against DRDOS.
At least on 386+ machines, DR-DOS 7.02+ has typically a lower
memory footprint than PC DOS, which - however - is more stable
and higher optimized than MS-DOS 6.22. On a 286 it highly depends
on the footprint of the HIMEM.SYS driver, which in turn depends
on the chipset of the motherboard. In some cases, the MS-DOS/
PC DOS HIMEM.SYS has a lower footprint.
You can use PC DOS 2000´s DPMS-enabled Stacker 4 under DR-DOS
(although I´m not sure if this will have an advantage for you on
on a 286), or use the DR-DOS 7.03 DPMS.EXE server (which has a
lower footprint than the old DPMS server that ships with PC DOS)
and almost all of the DPMS-enabled drivers under PC DOS 2000 if
you like (except for DELWATCH, which will run only under DR-DOS
because it needs certain hooks in the FDOS portion of the BDOS
kernel, which are simply not available on non-DR-DOS systems).
If you have a serial or PS/2 mouse, replace the mouse driver
(DRMOUSE?) by the CTMOUSE driver (see FreeDOS). DRMOUSE is
a derivation of an early CTMOUSE issue, and CTMOUSE has gone
through significant development meanwhile, including high
optimization. AFAIK the CTMOUSE memory footprint is around
3-5 Kb, but I think Arkady is reading this forum as well,
so he can probably better comment on it than me.
In case, you can get hold of a 6.30+ issue of the Logitech
mouse driver, it ships with a driver named CLOAKING, which also
provides a "cloaked" DPMS server. I have not been able to run
CLOAKING on a 286, but if you get it running on your 286, it
replaced the DR-DOS DPMS and additionally provides Cloaking
services, which are used by the Logitech mouse driver, so
that the Real Mode memory footprint shrinks down to ca. 1 Kb
(otherwise, the mouse driver takes 19 Kb).
Good luck and please report back your results. It´s always
interesting to learn about such case studies and once you
have established the general setup, we might help you with
some fine-tuning to squezze the last free bytes out of your
system (for which we would need to see your CONFIG.SYS and
AUTOEXEC.BAT and a MEM /A report)...
Matthias
--
<mailto:Matthias DOT Paul AT post DOT rwth-aachen DOT de>; <mailto:mpaul AT drdos DOT org>
http://www.uni-bonn.de/~uzs180/mpdokeng.html; http://mpaul.drdos.org
- Raw text -