ID:PW Pathworks and QEMM-386/DESQview
Quarterdeck Technical Note #220 Filename: DECNET.TEC
by Jonathan Niednagel CompuServe: DECNET.TEC
Last revised: 1/30/92 Category: NW
Subject: Running Digital Equipment's Pathworks (also know as DECNet or PCSA)
with Quarterdeck products.
PATHWORKS/DECNET from Digital Equipment Corporation
Pathworks, also referred to as DECNET or PCSA, is a multi-platform networking
package manufactured by Digital Equipment Corp. Pathworks as a general rule
works quite well with QEMM-386 and DESQview, as long as a few precautions are
taken. The following document outlines these areas of concern between
Pathworks and Quarterdeck products.
The Pathworks network is started by a batch file named STARTNET.BAT. This
file is approximately 200-250 lines in size. As of version 6.0, QEMM-386's
OPTIMIZE program can process CALLed batch files, a definite advantage for
Pathworks users. One problem that was encountered with Pathworks was the size
of this batch file. The OPTIMIZE program has a maximum of 9k of buffer space
allocated for each of the autoexec.bat, config.sys, and any CALLed batch
files. Often the STARTNET.BAT file is over 9k itself causing OPTIMIZE to
truncate the file to 9k, deleting the last several lines. Two solutions for
this problem exist. First, try deleting several of the REMark statements in
the STARTNET.BAT file, as approximately 50% of the file contains comments.
Second, the OPTIMIZE program which ships with QEMM-386 version 6.02 has been
modified to handle files up to 20k in size, instead of the previous limit of
9k. It is also important to remember to make backups of your CALLed batch
files. OPTIMIZE does NOT make backups of these files. Only the AUTOEXEC.BAT
and CONFIG.SYS are backed up by OPTIMIZE.
Another problem with STARTNET.BAT is EXECINFO.BAT. EXECINFO.BAT is a batch
file called from within STARTNET.BAT and uses an unusual (and needless) method
to re-enter STARTNET.BAT. The last line of it must be remarked out during the
OPTIMIZE process. This line is:
This causes STARTNET to start over, causing an infinite loop.
DNNETHLD & EMSLOAD
DNNETHLD is a loader of a similarly named file DNNETHAT. DNNETHAT is
approximately 50-55k in size. Using DNNETHLD loads this driver into EMS and
frees up approximately 45-50k. The problem with this loader (DNNETHLD) is
that it makes the incorrect assumption that the contents of the page frame do
not change during the handling of an interrupt. The EMS specification does
not warrant this assumption and Stealth keeps it from happening because the
Stealth technology causes a Stealthed ROM to be mapped into the page frame
when the ROM is used, as may happen at interrupt time. Even though this
assumption violates the EMS 4.0 specification, it was not a problem with QEMM-
386 until the Stealth feature of version 6.0. Stealth uses the page frame to
map ROMs into when the ROM is used. Although QEMM-386 saves the contents of
the page frame before it maps in a Stealthed ROM and restores those contents
to the page frame when it is done, Pathworks expects the contents of the page
frame to remain unchanged during the interrupt. Other EMS users can cause the
same problem for Pathworks. Remember that the memory gain from DNNETHLD is
approximately 45-50k yet the memory gain from using Stealth is 99k (assuming a
DEPCA card is being used) so the net gain is still over 60k when using
Stealth. EMSLOAD is a "generic" form of the same loader that can be used in
conjunction with some other Pathworks programs and displays the same type of
problems as DNNETHLD.
USING STEALTH WITH PATHWORKS
Using the Stealth with Pathworks can give you substantially more high RAM
which may allow you to load high all of the 140k+ network drivers that are
installed by Pathworks in most configurations. Placing the page frame at DC00
on top of the DEPCA ROM will give back 16k of memory. If the page frame is
not placed at DC00 (or wherever the DEPCA ROM begins) the DEPCA ROM must be
Stealth-excluded (XST=DC00; or XST=CC00, if this is where the DEPCA ROM
begins). The DEPCA cards that are used with Pathworks have two primary
configurations a 64k configuration at D000h and a 32k configuration at D800h.
Both of these have a 16k ROM at DC00 (the remainder being a RAM buffer).
Putting the page frame on top of the DEPCA ROM at DC00 gives back 16k that
would not otherwise be available. Remember that putting the page frame on top
of a ROM is only possible with QEMM-386 v6.0 and the Stealth feature.
The REDIR (redirector) command for Pathworks can be loaded into the HMA with
the /himem:yes switch. This puts 33k of REDIR into the HMA and leaves .9k in
conventional memory. While loading this driver in the HMA doesn't affect the
performance of QEMM-386 or DESQview, you will want to consider which one of
your HMA users is the most efficient. Since only one program can use the HMA
it would make sense to let the largest program use the HMA. Since DESQview
uses 63k of the 64k HMA, it is most often the best choice.
The driver DNNETH also has a problem with OPTIMIZE because LOADHI/GS (get
size) reports that 128k is needed to load this driver high when in fact it
only requires about 35k. Simply go to the OPTIONS menu on the second step of
OPTIMIZE and type "2" to change the information that OPTIMIZE has gathered.
The following screen will show the DNNETH driver (along with all others found
by OPTIMIZE) and give an "Initial size" and a "Final size". The "Initial
size" value must be changed to 35000 in order to load DNNETH high.
| DATA FOR THE OPTIMIZE PROCESS |
| Try to Load SQUEEZE Initial Final |
| Program High? Frame? Temp? Size Size |
| QEMM|86.SYS Y - - 12592 12592 |
| MOUSE.SYS Y - Y 31744 14832 |
| SETVER.EXE Y - Y 13984 576 |
| FILES Y - Y 4480 4032 |
| * DNNETH Y - Y 131392 31384 |
| LSL Y - Y 58112 33536 |
| NE2000 Y - Y 13456 4160 |
| IPXODI Y - Y 58128 14816 |
| TCPIP Y - Y 57680 21440 |
| EMSNETX Y - Y 62944 9344 |
| Arrow keys to select or Space to toggle |
| CAUTION: Changing this data may have adverse affects |
| ____________________________________________________________ |
| Enter to Accept Changes Esc to Undo Changes |
| _________________________________________________ |
* Change this program to show an Initial Size of 35K (35000)
All tests at Quarterdeck were done with Pathworks v4.1 on a MicroVAX 3100.
PC's were equipped with either Compaq DOS 3.31 or MS-DOS 5.0. and the DEPCA
family of boards. Users of 3COM cards should reference LANMAN.TEC technical
note from Quarterdeck for additional information regarding their specific
*This technical note may be copied and distributed freely as long as it*
*is distributed in its entirety and it is not distributed for profit. *
* Copyright (C) 1991-2 by Quarterdeck Office Systems *
************************ E N D O F F I L E *************************