
             Updated Phar Lap Dos Extender for
                      AutoCAD 386 R12
                              
A new Phar Lap DOS Extender, version 4.1-ACAD2, when accompanied
with the appropriate DPMI patches from IBM, allows AutoCAD Release
12 386 to run in an OS/2 2.0 Full Screen Dos Box.


                     by Autodesk Product Support
                     November 2, 1992
                              
                              
                              
DOS Extender 4.1-ACAD2 is an update to version 4.1-ACAD which AutoCAD 386
currently uses.  The DOS Extender is an integral part of AutoCAD 386.
This document will describe how to update the DOS Extender in place.
Here are some of the benefits of the updated DOS Extender:



DOS Extender 4.1-ACAD2 Benefits
====================================

   * Ability to run AutoCAD 386, R12 in a full screen OS/2 dos box.

NOTE
====

With Dos Extender 4.1-ACAD2, AutoCAD 386 R12 should run from
a dos prompt, within Microsoft Windows 3.1 as a full screen Dos Box Application
and with OS/2 2.0(and DPMI Patches) as a full screen Dos Box Application.

This update need only be done if you are interested in running AutoCAD
386 R12 in an OS/2 2.0 Dos Box. The environment for running
AutoCAD 386 in an OS/2 Dos box is very similar to running within
a Dos Box under Windows 3.1. Please refer to the section
"Running AutoCAD 386 under Windows" in the Release 12 Installation
and Performance Guide.

In addition to updating the dos extender within AutoCAD R12, it
is also necessary to update the display driver "rcpsvadi.exp." This
is more commonly known as the "SVADI" driver. A new version of
this driver is enclosed on the update disk as well.


Dos Extender 4.1-ACAD2  - A Word of Caution
================================================

    Due to inconsistencies between AutoCAD R12 386 and OS/2 2.0,
    AutoCAD R12 and R12c1 will not run in a DOS window under OS/2 out 
    of the box.  Autodesk and IBM collaborated to correct these 
    inconsistencies by developing software patches for both R12 and OS/2.  
    The patches are now complete, but they have not been extensively tested.  
    In the interest of providing these patches as soon as possible, Autodesk 
    has decided to release its patches in Beta form.The 
    patches have not completed all testing that is normally conducted on 
    released software so USE THEM AT YOUR OWN RISK.  You need to obtain
    the IBM code from IBM.
 

    To obtain the IBM patches, you will need to get the OS/2 2.0
    ServicePack directly from IBM. For more information about
    this ServicePack, call IBM HelpWare at 1-800-772-2227.



How to update your copy of AutoCAD 386 R12 to use DOS Extender 4.1-ACAD2
=============================================================================

A program called NEWDX.EXE has been supplied on the enclosed DOS
Extender update disk.  NEWDX will remove DOS Extender 4.1-ACAD from
AutoCAD 386 and replace it with version 4.1-ACAD2.

NEWDX will work with AutoCAD R12 C0 and AutoCAD R12 C1. If you
are using a digitizer, we recommend that you upgrade to AutoCAD
R12 C1 for improved digitizer performance.

This procedure should be done on the installed copy of AutoCAD 386,
and NOT on the original floppies.  The operational steps are as
follows:

  1.  Change directories to your AutoCAD 386 executable directory.

      cd \acad

  2.  Back up your copy of ACAD.EXE, i.e.  copy ACAD.EXE to
      ACADSAV.EXE.

      copy acad.exe acadsav.exe.

  3.  Copy the Dos Extender update program into the executable directory,
      i.e.  copy A:newdx.*

      copy A:newdx.*

  4.  Execute the program NEWDX.EXE by typing,

      newdx acad.exe

  5.  NEWDX preserves any DOS Extender switch settings that you may
      have had in the earlier version of the DOS Extender.


  6.  If for any reason you encounter problems with DOS Extender
      version 4.1-ACAD2, simply copy back the saved executable into
      ACAD.EXE.

      copy acadsav.exe acad.exe


  7.  Update the "rcpsvadi.exp" driver.

      cd \acadr12\drv
      copy rcpsvadi.exp rcpsvadi.sav
      copy A:rcpsvadi.exp

      The updated driver contains a workaround for an OS/2 bug. It will
      work fine on all environments.

OS/2 2.0 Kernel and DPMI Patches
================================


In order to run AutoCAD 386 R12 in an OS/2 dos box, you will need
an OS/2 kernel patch and new DPMI drivers. These files are available
from IBM in the OS/2 2.0 ServicePack. Please install the 
ServicePack patches before trying to run AutoCAD R12 on an OS/2 2.0
system.



Running AutoCAD 386 R12 in an OS/2 Dos Box
==========================================

In order to get optimum performance of AutoCAD 386 R12 under OS/2 make
the following changes to your OS/2 Dos Full Screen Session Settings:


	Change DOS_FILES to 50
	Change DPMI_MEMORY_LIMIT to 40  (40MB)
	Change HW_TIMER to on

	Settings you may want to change:(Not tested here)

	IDLE_SENSITIVITY -- change to 100 if using serial devices
	DOS_HIGH -- why not.
	COM_HOLD to on
	Video_8514A_XGA_IOTRAP -- for 8514 people
	COM_DIRECT_ACCESS

    AutoCAD 386 will only take memory from the DPMI memory pool. The settings
    for EMS and XMS have no affect on AutoCAD 386.



General OS/2 System Requirements
================================

OS/2 runs AutoCAD 386 much better with 16MB than 8MB. The switch time 
between applications is much better. Even more memory may be required
if you wish to run multiple sessions of AutoCAD.


Known Problems
==============

We did all of our testing on the VGA graphics subsystem. When we
tried to make AutoCAD 386 use XGA support inside the dos box,
erratic behavior occurred. We recommend using the "SVADI"
display driver choice for AutoCAD and choosing VGA mode for
AutoCAD 386. IBM is aware of the problems with XGA support.

Just as when running AutoCAD 386 under Windows, we recommend
running AutoCAD at 600x480x16 or 800x600x16 display resolution.
Higher resolutions or more colors may cause problems unless
the display driver has an intelligent screen grabber.

Some beta users have noticed that digitizer performance within the OS/2
dos box is not as good as under straight dos.



