                                   
     +==========================================================+
         README.TXT - AutoCAD Release 13c4 General Information
     +==========================================================+
                                   
                            4 January 1996



This file contains last minute additions and corrections that are not
included in the documentation.

=====================================================================-
CONTENTS
========-

  - Platform Independent Information
  - Geometry Information
  - AutoCAD Render
  - ASE Information

Important: For installation information, refer to the INSTALL.TXT
file.

The following list describes the R13c4 readme files:

README         Contains general information related to all platforms.
READPC         Contains DOS-specific and Windows-specific information.
READDOC        Contains documentation updates and revisions.
READDEV        Describes the text files that explain how to compile,
               link, and debug ADS and ARX applications, and tells
               where to find them.
READHIST       Describes the history of enhancements, fixes, and
               information related to each of the R13 update releases.



=====================================================================-
PLATFORM INDEPENDENT INFORMATION
================================-

  - Contacting Autodesk
  - What's New in Release 13
  - R13c4 Compatibility Information
  - Using Autodesk WorkCenter with R13c4
  - Using Drawings between Platforms
  - Long File Names
  - Using Transparent Commands at a File Prompt
  - Electronic Documentation
  - Advanced Documentation on CD-ROM
  - Platform-Independent Help from a CD-ROM or a Read-Only Directory
  - Undo File on Disk
  - Add-on Applications, Custom Objects, and Zombies
  - Use of ERASE, PURGE, and OOPS
  - Dimensioning Issues
  - Font and Shape Issues
  - Multiline Properties
  - Release 12 Compatibility Issues
  - AutoLISP Issues


Contacting Autodesk
===================-
You can contact Autodesk at the following locations:

+   Autodesk's Web site at  http://www.autodesk.com
+   Autodesk's FTP site at  http://ftp.autodesk.com
+   The Autodesk Forum on CompuServe (GO ACAD)
+   The Autodesk Global Village Bulletin Board in the USA at (415)
    507-5921


Autodesk on the Web
-------------------
Autodesk's Web site on the Internet is accessible via a Web Browser at
http://www.autodesk.com.  Information is organized in twelve
categories, including What's New, About Autodesk, Products, Product
Support, Market Groups, Education and Training, Government, User
Groups, Developers, Job Search, Interviews and Send Us Your Thoughts.


AutoCAD Technical Publications
------------------------------
You can contact the AutoCAD Technical Publications department with any
comments, suggestions, or problems regarding the AutoCAD documentation
by sending an email to acad_docs@autodesk.com.


What's New in Release 13
========================-
For information on what's new in AutoCAD Release 13, select "What's
New in Release 13" from the AutoCAD Help menu. The READHIST Help file
(and READHIST.TXT file for DOS) provides the history of enhancements,
fixes, and information related to each of the R13 update releases. For
a history of all AutoCAD revisions see the HISTORY Help file.


R13c4 Compatibility Information
================================-
Because of new technologies used in AutoCAD Release 13c4, there are a
number of compatibility issues of which customers should be aware:


Applications
-------------
Please be aware that NOT ALL existing AutoCAD Release 13 based
applications work with AutoCAD Release 13c4.  Because of new
technologies in this release, products that use the AutoCAD ARX
development environment will need to be updated in order to work with
R13c4. This affects Autodesk products, as well as independently
developed applications.

Before installing this update, please refer to the following
compatibility information to determine whether your application is
affected.

AutoVision R2 -- Requires updating to R2c4; this update is included on
the AutoCAD R13c4 media.

Designer 1.2 -- Requires upgrading to Designer 2.0 or Mechanical
Desktop; contact your Authorized AutoCAD Dealer.

AutoSurf 2.1 -- Requires upgrading to AutoSurf 3.0 or Mechanical
Desktop; contact your Authorized AutoCAD Dealer.

IGES Translation R13 -- Requires updating to R13.1; contact your
Authorized AutoCAD Dealer.

WorkCenter 1.1 -- Compatible except that AutoCAD/WorkCenter file open
redirection is unavailable.  This feature will be updated.  Contact
your Authorized WorkCenter Dealer.

Independent Applications -- Incompatible if application utilizes ARX
functionality; contact your application developer or reseller.
Autodesk publishes compatibility listings provided by developers on
its web site at www.autodesk.com.


R13 Solids
-----------
AutoCAD's ACIS solid modeling engine has been updated (from 1.5 to
1.6) with R13c4. Existing ACIS 1.5 models opened in R13c4 are
converted automatically. Backwards compatibility is controlled by the
ACIS15 system variable which determines whether an ACIS 1.5 model is
also created.


OLE
----
OLE 1.0 objects contained in existing AutoCAD drawings are optionally
converted to OLE 2.0 objects when opening the drawing in R13c4.
Objects must be converted to OLE 2.0 in order to be displayed in
R13c4, and once converted, cannot be displayed in prior AutoCAD
releases.


Win32s
-------
Version 1.25a of the Microsoft Win32s subsystem is required for
running R13c4 under Windows 3.1x. This version is included on the full
media set and will be posted to the electronic forums.


Using Autodesk WorkCenter with R13c4
====================================-
Autodesk WorkCenter 1.1 supports R13c4. However, the file dialog
interceptor is disabled. To make it work again, obtain the R13c4
compatibility update to Autodesk WorkCenter 1.1 from your dealer. It
is also available from the Autodesk Forum on CompuServe, the Autodesk
Global Village Bulletin Board in the USA (415) 507-5921 and the
Autodesk World Wide Web Site http://www.autodesk.com.


Using Drawings between Platforms
=================================-

Long File Name Issues
---------------------
Now that AutoCAD recognizes long file names on the NT and Windows 95
platforms, the possibility of file transfer between platforms that
recognize long file names and those that don't (DOS and Windows 3.1)
has increased. If you work in an environment with mixed platforms, you
should develop and adhere to file naming standards that are
appropriate for all platforms. For additional information see the
section entitled "Long File Names" in this file.


Menu File Syntax
----------------
The menu file syntax has been modified for Release 13 AutoCAD for
Windows to provide additional functionality. These menu files are not
recognized by Release 13 DOS and UNIX AutoCAD. If you save a drawing
in Windows and then open it in a DOS or UNIX version, the menu may not
appear as desired. Use the MENU command to load the menu file. AutoCAD
for Windows recognizes both the old and the new syntax.


Long File Names
===============-
The following issues should be observed when using long file names:
+   When using AutoCAD for Windows 95 in a networked environment
    where some systems are running Windows 3.1 or DOS, it's best to
    configure AutoCAD for 8.3 filename compatibility. 8.3
    compatibility mode disables support for long filenames within
    AutoCAD, thus avoiding any problems recognizing these files in
    the 8.3 limited operating environments.
    External references are one area where problems might arise when
    using long filenames in a mixed environment. If an external
    reference is created from a drawing with a long filename, this
    external reference will not be automatically resolved by AutoCAD
    running under DOS or Windows 3.1. You will have to type the 8.3
    equivalent name to resolve external references with long
    filenames on DOS or Windows 3.1. The 8.3 equivalent name is
    assigned by the operating system that created the file and
    contains some of the original characters from the filename along
    with tildes (~). This is the filename that you see when you list
    the files on a DOS or Windows 3.1 system.
+   Microsoft's common file open dialog as used in AutoCAD, does not
    support filenames with embedded spaces when the multi-select
    option is set. To avoid this problem, when a dialog allows more
    than one filename to be picked, AutoCAD displays the 8.3
    equivalent name for filenames containing spaces.
    This behavior is evident in the UNLOCK and DELETE options of the
    FILES command.
+   Windows 95 and Windows NT will not allow you to create two files
    with the same name but different case. For example, if you have a
    drawing file named "my drawing.dwg" and try to save your current
    drawing as "My Drawing.dwg", AutoCAD will prompt you with "file
    already exists, overwrite?". AutoCAD, like Microsoft
    applications, behaves this way because these operating systems
    are case preserving, but not truly case sensitive.
+   In some instances, a filename with embedded spaces must be
    enclosed in double quotes. For example, with FILEDIA set to 0,
    you can type the following at the command prompt:
      open
      Enter name of drawing: My file
    and press return to open MY FILE.DWG. In a script however, "MY
    FILE"  must appear in double quotes. The double quotes are
    necessary to  preserve script compatibility in the case where the
    command is terminated  by a space instead of by pressing return.
    Similarly, the AutoLISP startapp function requires double quotes
    on  any single argument which contains embedded spaces. To
    execute  MY NOTEPAD.EXE to edit README.DOC from startapp, you
    would type:
      (startapp "\"MY NOTEPAD.EXE\" README.DOC")
    The backslash (\) preceding the double quotes preserves the quote
    marks around the filename and prevents startapp from interpreting
    My Notepad.exe as two separate arguments.
+   The AutoCAD Open dialog allows you to preview drawings, even if
    the filename is invalid. Of course, the only way to get a drawing
    file with an illegal name would be to rename the file from
    outside of AutoCAD.
    For example, Microsoft Windows 95 UI guidelines specify that
    applications should strip leading and trailing spaces from file
    names. Therefore, AutoCAD does not allow you to save or load file
    names with leading or trailing spaces. However, AutoCAD will
    display a file name with leading or trailing spaces in the Open
    dialog box, and the Open dialog box will still show a preview of
    this drawing.
+   For several AutoCAD filetypes, AutoCAD does not handle file names
    with multiple extensions as you might expect. For example, if you
    want to compile a shape file with the name, FOO.BAR.SHP, you
    might simply enter FOO.BAR to the COMPILE command. AutoCAD opens
    the file FOO.BAR.SHP even if only FOO.BAR is entered. However,
    the COMPILE command creates a compiled shape file named FOO.SHX
    instead of FOO.BAR.SHX.
    The work-around for this problem is to enter the full file name,
    including both extensions, when using file names with multiple
    extensions. In the previous example, entering the name
    FOO.BAR.SHP correctly compiles to FOO.BAR.SHX.
+   AutoCAD does not consistently handle long file names containing
    commas. For example, AutoCAD lets you use SAVEAS with a drawing
    name of 123,456.DWG. However, AutoCAD can only open this drawing
    through the file dialog (with FILEDIA = 1). Attempting to open
    this drawing from the command line (with FILEDIA = 0) results in
    the following error message "Cannot find the specified drawing
    file." Similarly, DXFOUT lets you to create 123,456.DXF, but
    DXFIN produces the error message "123.DXF File not found".
+   If a path is not specified for the autosave file, the following
    incorrect warning message appears at autosave time:
      WARNING: invalid or read only directory specified for autosave.
            Saving to: "<path/filename>"
    where <path/filename> indicates the location and name of the
    autosave file.
    NOTE:  The autosave is still happening!
    To avoid this message in the future, specify a path as part of
    the autosave file name.
    Under the previously described circumstances, AutoCAD will first
    attempt to write the autosave file to the configured temporary
    directory, and if that is not available it will be written to the
    current drawing directory.


Using Transparent Commands at a File Prompt
===========================================-
Because Windows 95 and Windows NT filenames can contain the single
quote character, it is no longer possible to issue a transparent
command at a file prompt. An attempt to call a command transparently
results in AutoCAD trying to use the quote+command name (for example
'ZOOM) as a filename. The transparent command should now be issued
before or after the file prompt.


Electronic Documentation
========================-
Several new features have been added to the edocs including an
upgraded DynaText 2.3 browser, a dynamic back-of-book index, searching
across collections of books, and faster scrolling capability. These
features are described below:

+   Searching across collections of books. To search across the
    AutoCAD collection, type your search query in the Find box in the
    main DynaText window. Numbers will appear to the right of each
    book title showing the number of times your search item was
    found. When you open a book, numbers will appear in the table of
    contents to the left of each entry.

+   A dynamic back-of-book index. To access the index, open any
    AutoCAD manual. From the main menu, choose Tools and then Index.
    NOTE:  It may take from 10 to 15 seconds for the index window to
    appear.

+   Predefined Search Queries. Open any AutoCAD book. From the main
    menu, choose book and then Search History. Click the down arrow
    beside search forms. Choosing an item from the list will restrict
    the search to specific areas of the book.

+   Creating Journals. With the Journals toolbar, you can create your
    own browsing path through the books. From the main menu choose,
    Journal, New. Choose the record button from the toolbar. Scroll
    down through the current book or choose other books. when you are
    finished, press Stop.
    NOTE:  There is no save button on the Journal Toolbar. To save a
    journal, click on the status bar and choose close. You will be
    prompted to save your file.


Installing Edocs
----------------
Electronic documentation is only available on the CD version of
AutoCAD. If you choose the Typical Install option on the R13c4 AutoCAD
CD, the edocs are installed automatically. If you perform a Custom
Install, you need to make sure the Electronic Documentation option is
marked with an x.

To install the edocs only, deselect all of the other items except
Electronic Documentation.

After installing AutoCAD for Windows 3.1x or Windows NT, a green book
icon will appear in the AutoCAD program group. Clicking on the icon
will bring up the DynaText 2.3 edoc browser.

NOTE:  you must have the CD in the CD-ROM drive to access edocs. If
the CD is not in the drive, you will receive an error message.


Known Edoc Bugs
---------------
  -- In the Command Reference, the initial value for the SAVEIMAGES
system variable is 50. This value should be 0.

  -- If you use a very general word for a search like you're or your,
you will receive a message saying, "DynaText error, an item is on the
stop list." When you click OK, DynaText will find your search anyway.


Advanced Documentation on CD-ROM
================================-
The diskette version of AutoCAD Release 13 contains basic
customization tools such as AutoLISP and associated documentation. The
programming interface files for ADS and ASE development, as well as
all the advanced customization documentation, are only available on
the CD version of AutoCAD Release 13. This electronic documentation is
part of the complete documentation set available on the CD version.


Platform-Independent Help from a CD-ROM or a Read-Only Directory
================================================================-
AutoCAD writes a binary index (.HDX) file the first time it reads a
Platform Independent (PI) Help file (.AHP). Normally, this file is
written to the same directory where the Help source file is found. If
the source file is in a read-only directory (for example, a restricted
network drive or a CD-ROM), this file can't be written to the Help
source file directory.

The following sequence illustrates how PI Help places the .HDX file.
You can force AutoCAD to place the .HDX file anywhere on the ACAD path
by placing a dummy .HDX file in that directory.

    - find the help source file
    - can I open an index file for writing that directory?
    - yes SUCCEED
    - no
    - look for an index file of that name on the ACAD path
    - find one?
    - yes, can I open an index for writing there?
    - yes, SUCCEED
    - no, keep trying
    - no, look for acad.ini on ACAD path
    - find it?
    - yes, can I open an index for writing there?
    - yes SUCCEED
    - no FAIL

The next time, the same logic is used to find the built index file.
The message "Help index in: xxx." displays on the command line to
indicate where the file was written.


Undo File on Disk
=================-
The Undo file (the record of all actions since opening the drawing)
was previously maintained in RAM. This reduced the amount of available
swap space and RAM. The UNDOONDISK system variable was added to allow
users the ability to specify whether the Undo file is maintained in
RAM or on the hard disk. The default setting (1) specifies that this
file is kept on the hard disk. See the Manual Corrections and
Additions, AutoCAD Command Reference section for details.


Add-on Applications, Custom Objects, and Zombies
================================================-
A zombie is a read-only object that is created automatically when
AutoCAD opens a drawing and tries to generate an entity which is
defined by a custom class and the application defining the class is
not loaded. Zombies are of class AcDbZombieObject or AcDbZombieEntity.
A zombie entity can have graphics and can be visible. A zombie object,
on the other hand, will never have graphics. Zombies are also created
in memory when the application defining a custom class is unloaded. If
the drawing is subsequently saved to a DXF file, any zombies in memory
are written out as zombies. Without the application, AutoCAD has no
knowledge of how to write out the real object in DXF format, so it
writes it out as a zombie.

When a DXF file containing custom entities is read in and the
application is missing, zombies are not created. The custom entities
are simply discarded. This situation can cause serious problems if
your application depends on these custom entities.


Saving Zombies to a DXF File
-----------------------------
Zombies usually reside only in memory. The only case when a zombie is
written out is when a DWG file is read in, zombies are created because
the application is missing, and the file is subsequently saved to a
DXF file. In this case, the DXF file contains instances of class
AcDbZombieObject or AcDbZombieEntity.


Resurrecting Zombies
---------------------
Zombies are resurrected (that is, turned back into real custom objects
or entities) when the missing application is subsequently loaded.
Note, however, that zombies are not resurrected when a DXF file
containing zombies is read in (using the DXFIN command). Even if the
defining application is already loaded, the zombies in the DXF file
remain zombies until the application is reloaded (which then causes
the zombies to wake up).


Use of ERASE, PURGE, and OOPS
=============================-
Issuing the OOPS command to unerase an object whose layer (or other
associated named object) has been subsequently purged is disallowed.


Dimensioning Issues
===================-

DIMUNIT and DIMALTU
-------------------
The new values for DIMUNIT and DIMALTU (values 6 and 7) are not
accepted by the LUNITS system variable because the units formatting
controlled by LUNITS cannot result in an mtext stack.


The Affect of DIMCONTINUE on Dimension Variables
------------------------------------------------
Regardless of the current dimension style, DIMCONTINUE affects linear
dimensions, by turning DIMSE1 On, to suppress the first extension
line, and setting DIMFIT to 4, to allow the text to move independent
of the dimension line.


Right angled Arrowhead
----------------------
The block name for the Right-angle arrowhead is named "OPEN90" to make
it consistent with the international versions of AutoCAD.


Numbers in Stacked Fractions
----------------------------
The relative sizes of numbers in stacked fractions are now based on
the DIMTFAC system variable (in the same way that tolerance values use
this system variable).


Font and Shape Issues
=====================-

MTEXT and Vertical Fonts
------------------------
Tolerances, multiple lines, underlined text, stacked fractions and
obliqued characters created with vertical fonts in MTEXT don't display
correctly.


MTEXT, Import Option
--------------------
The largest file size that can be handled by the Import option of
MTEXT is 4K bytes.


Shape (.SHP) Files
------------------
The shape (.SHP) files are provided on the CD only.


Multiline Properties
====================-
Use the MLSTYLE command to set up a multiline style for the multiline
you're going to create. Establish the colors and linetypes of the
multiline elements in the Multiline Style dialog boxes.

Once you've established the colors and linetypes in the multiline
style and you've created the multiline, you can't change these
properties. You must create a new multiline style with the properties
you want and create a new multiline.

Using CHANGE, CHPROP, or DDMODIFY to alter the properties of an mline
does not result in any visible changes. Use MLSTYLE to specify the
properties of an mline before creating it.


Release 12 Compatibility Issues
===============================-

Using Release 12 Files in Release 13
------------------------------------
When you open a Release 12 drawing file in Release 13, it is converted
to Release 13 format. Release 12 drawings display differently as they
are loaded into Release 13 than do Release 13 drawings. Release 12
drawings regenerate after they are loaded into memory, causing a delay
before you see anything drawn on screen. Release 13 drawings
regenerate as they are being loaded.

In the unlikely event that Release 13 crashes, you will be prompted
with the option to save the drawing. If you respond with a Yes, the
drawing is saved in R13 format and will require recovery (done
automatically during the OPEN process). It is important to note that
the original drawing is renamed with a .BAK extension and can be
opened after renaming it with a .DWG extension.

If you need to keep the drawing in Release 12 format, either mark the
file as "read only," or load it into Release 13 and use the SAVEASR12
command to save it to a file in Release 12 format.


DXFOUT Precision for Release 12 AME Solids
------------------------------------------
It's recommended that you use the maximum precision (16) when using
DXFOUT on Release 12 AME solids for use in Release 13. If you use a
low precision with DXFOUT, data might be incorrect and some operations
might fail.


Layers Marked as DELETED
------------------------
When opening a Release 12 drawing with layers marked as DELETED
(typically converted from other CAD applications), AutoCAD places
objects on those layers on layer 0.


AutoLISP Issues
===============-

Using entmod with the Mlinestyle and Group Dictionaries
-------------------------------------------------------
The use of the entmod function with the mlinestyle dictionary is not
supported in R13c4, however this is supported with the group
dictionary.


The LONGFNAME System Variable and AutoLISP File Handling Functions
------------------------------------------------------------------
The AutoLISP file handling functions (open, close, etc..) do not check
the LONGFNAME system variable for validation of a file name. If
LONGFNAME is set to 0 (Off), the open function will accept a file name
that exceeds the DOS 8.3 file name length. Any characters in excess of
8 are truncated.


=====================================================================-
GEOMETRY INFORMATION
====================-

  - Conversion of ACIS Objects Between c3 and c4
  - Extrusion and Elevation Change of Solids and Other Objects
  - Sample Solid Models on CD-ROM
  - Known Geometry Limitations


Conversion of ACIS Objects Between c3 and c4
============================================-
In R13c4 the ACIS solid modeler has been upgraded to version 1.6. The
ACIS15 system variable provides the conversion between ACIS version
1.5 and ACIS version 1.6.

ACIS15

Type: Integer
Not saved
Initial value: 0

Converts ACIS-specified entities such as 3d solids, bodies or regions
between c3 and c4. The setting of this variable has no effect on
ellipses and splines since data for these entities isn't ACIS-
specific.

0   All ACIS data is saved in c4 (ACIS 1.6) format and can only be
    read by c4 or later versions.
1   All ACIS data is saved in both c3 (ACIS 1.5) and c4 (ACIS 1.6)
    format in two different places. ACIS 1.5 format data is saved in
    the usual place where ACIS-specific data is retained. ACIS 1.6
    format data is retained in the extension dictionary of the object
    along with a checksum of the ACIS 1.5 data. This checksum is used
    to check if the ACIS 1.5 data has changed. If it's changed,
    AutoCAD reads the changed data, otherwise it reads the ACIS 1.6
    data in the extension dictionary. This ensures that you are able
    to use a drawing saved in c4 and open it in c0-c3 and to make
    modifications to ACIS-specific entities in the earlier releases
    and then to use that drawing in c4.

Note: For DXF files, if ACIS15 is set to 1, AutoCAD saves the ACIS-
specific data in ACIS 1.5 format in the usual place, and there's no
storage of ACIS 1.6 data in the extension dictionary.

Commands affected by the ACIS15 system variable are:

   SAVE
   OPEN
   DXFOUT
   DXFIN
   ACISOUT
   ACISIN

Note: 3dsolids, body and region entities represented by the ACIS 1.6
format can't be restored by c3, even if ACIS15 is set to 1. These
entities will be disregarded and should not affect other valid solid
entities.


Extrusion and Elevation Change of Solids and Other Objects
==========================================================-
It is not recommended that spline objects or 3dsolid, body, or region
objects that contain a spline as one of their faces or edges, be
extruded to a very large value (greater than 1e19). In some cases
(specifically on the NT platform) a severe crash can occur and AutoCAD
will exit without giving the user a chance to save the drawing. This
can also occur when you change the elevation of these objects to a
very large value (such as 1e23).

If you must perform this type of extrusion or elevation change we
recommend that you save the drawing prior to performing the operation.


Sample Solid Models on CD-ROM
=============================-
Solid models are included with the Release 13 base system. These
models provide full 3D descriptions of an object, suitable for
rendering. One model, STEERING.DWG, is included with the Examples and
Samples option of the AutoCAD install/setup. Additional example models
have been included on the CD-ROM. Because of their size, they're not
installed as part of Release 13, however, you can either copy them to
your hard drive or open them directly from the CD. To provide the best
display of each model, use the HIDE command.

The SAMPLE directory of the CD contains:

File name      Description
-------------  -------------------
ROBOT.DWG      Industrial robot
SHAVE.DWG      Disposable razor
CARWHEEL.DWG   Car wheel
DUCTPATH.DWG   Profile along a path
STEERING.DWG   Steering wheel


Known Geometry Limitations
==========================-
If you make use of the new solids modeling features in Release 13, you
should review the following items.


ACIS 1.6 to ACIS 1.5 conversion problem
---------------------------------------
AutoCAD can save ACIS 1.6 parts as ACIS 1.5 parts (see "Conversion of
ACIS Objects Between c3 and c4"). There is a known problem with saving
certain types of rolling-ball blend surfaces. In particular, when the
rolling ball blend has an ellipse as a spine, ACIS 1.5 will not be
able to read that part when saved from ACIS 1.6 (the spine is the
curve swept out by the center of a rolling ball). An example of this
type of surface results from a blend along a cylinder/plane
intersection when the cylinder is not oriented perpendicular to the
plane. In order to read a part having this problem, it is necessary to
upgrade to R13c4.


Canceling modeling operations
-----------------------------
There are known memory leaks when you cancel solid and region modeling
operations by pressing CTRL+C or ESC. If you cancel a lot of modeling
operations in one AutoCAD session, AutoCAD might use up all available
memory and crash.


Solids with poles
-----------------
Solids with poles can lead to failures during Boolean operations, mass
property computations, sectioning, slicing, interference checking, and
so on.

Such solids result mostly from the TORUS command where the major and
minor radii are equal, and from the REVOLVE command where the region
being revolved touches the axis of revolution.


Boolean operations
------------------
Boolean operations between solids with nearly tangent faces don't work
reliably. Eliminating the tangency or making the faces exactly tangent
should help.


Revolved solids
---------------
If the axis of revolution touches the region being revolved, further
operations on the solid created could fail. Some possible workarounds
include
+   Making sure that the region isn't tangential to the axis at the
    point(s) of contact.
+   Making sure that the edges that touch the axis are as simple as
    possible. If an edge touching the axis is a spline curve,
    replacing a small portion of that curve near the point of contact
    with a line or a circular/elliptical arc will help.


Tapered extrusions
------------------
Extruding a region with a taper angle can result in a self-
intersecting solid. Further operations on such a solid won't work
reliably. The EXTRUDE command doesn't catch and report self-
intersections in the solid created. Self-intersections can be
eliminated by reducing the extrusion height or the taper angle.


Section and slice through rolling ball fillets
----------------------------------------------
Sectioning or slicing a solid through rolling ball fillet faces
doesn't work reliably. This problem occurs more frequently when the
plane passes through the edge where the fillet face meets the
neighboring face.


Non-manifold edges and vertices
-------------------------------
Non-manifold edges and vertices may cause problems during Boolean
operations, particularly when the two solids intersect at these non-
manifold objects.


Coincident faces, edges, and vertices
-------------------------------------
Coincident or almost coincident faces, edges and vertices and other
singular cases may cause problems during Boolean operations.


Using FILLET and CHAMFER with 3D solids
---------------------------------------
The following are issues to note while using the FILLET or CHAMFER
commands for 3d Solids.
+   Filleting is a local operation, so if the fillet data causes the
    new fillet geometry to interfere with nonadjacent edges or faces,
    the result could be failure of the FILLET command or even an
    invalid solid.
+   Filleting a mixed-convexity edge case quite often has problems.
    That is, if one of the three edges at a vertex has a different
    convexity than the other two, then it is susceptible to failure.
    One workaround is to fillet the odd convexity edge separately,
    and then select the smooth sequence (of three edges) created.
+   If all the edges incident at a vertex have their tangents lying
    in the same plane and it's desired to fillet them, and
    simultaneous selecting of them fails, try selecting (and
    blending) them singly.
+   Filleting an edge results in a new blend surface. Often, this
    surface needs to be "capped" by extending nearby surfaces, so
    that the blend surface is restricted properly to define a valid
    resulting solid. ACIS has problems when the capping operation
    requires the extension of spline surfaces. This isn't currently
    supported.
    In general, operations involving spline curve and surface
    geometry are more prone to failure than other operations. This
    will continue to improve with subsequent releases of ACIS.
+   In some situations, single edge filleting, where the edge is C1
    continuous with an adjacent edge, is not possible. This mainly
    happens when one of the two edges is a spline curve. Typically,
    however, where one of the edges is a line and the other is an
    arc, single edge filleting works.
+   An edge whose two adjacent faces are C1 continuous throughout
    can't be filleted. In general, if ACIS isn't able to fillet an
    edge since it's invalid, or it's a current ACIS limitation, the
    message "Cannot blend this edge" is displayed.
+   Chamfer of a single edge that has at least one adjacent tangent
    edge isn't well handled in ACIS currently, and isn't being
    allowed.
+   Only chamfers of line and circle-arc edges are permitted.
+   Chamfering is a local operation, so if the chamfer data causes
    the new chamfer geometry to interfere with nonadjacent edges or
    faces, the result could be failure of the CHAMFER command or even
    an invalid solid.
+   ACIS has problems handling simultaneous selection of mixed-
    convexity adjacent edges sometimes and fails to chamfer the
    selected edges. In such cases, chamfering each edge individually
    often provides the desired results.


Section planes
--------------
The SECTION command says that the section plane does not intersect the
solid even though the plane may be passing through an edge or a vertex
of the solid. If there's some common area shared between the solid and
the section plane, a region enclosing that area will result.
Otherwise, the SECTION command will say that there's no intersection
between the section plane and the solid.


Effects on objects using ACISOUT to ACISIN
------------------------------------------
Some AcDb3dSolid objects will become AcDbBody objects when they're
written out through ACISOUT and read back in through ACISIN. Because
all non-manifold ACIS bodies are converted to AcDbBody objects during
ACISIN. Some of these ACIS bodies could qualify as AcDb3dSolid objects
even though they are non-manifold. But there's no reliable way to
check at this time if an ACIS body is a valid (manifold or non-
manifold) solid.


Effect of DISPSILH with HIDE
----------------------------
If the DISPSILH variable is ON, the HIDE command will display
AcDb3dSolid objects with silhouette edges only. It won't show the
internal edges produced by facetting the object.


Effect of offset operation on higher order splines
--------------------------------------------------
Offset operation on higher order splines may not be successful. Also,
multiple offset operations on splines, i.e. offset of an offset
spline, has the potential of splitting the resulting spline into
multiple small segments resulting in a curve that might not be very
useful for future operations. For example, you might not want to use
such a spline as a path to extrude along since it will end up creating
a large number of sweep sections.


Extruding profiles along a path
-------------------------------
While extruding profiles along path, avoid creating profile and path
combinations that could result in self-intersecting solids. For
example, this could happen in extruding larger profiles along paths
that have high areas of curvature, i.e. tight corners.


How ACISOUT saves ACIS bodies
-----------------------------
ACISOUT command saves the ACIS bodies using the api_save_entity_list()
call. To read these bodies, api_restore_entity_list() must be used.


=====================================================================-
AUTOCAD RENDER
==============-

  - Incompatibilities and Limitations
  - Configuration
  - Autodesk Trademarks


The following Render terms are used in this document:
AutoCAD Render: Name of the ADS/ARX rendering application supplied
               with AutoCAD Release 13
R13 Render:    Used interchangeably with AutoCAD Render
RENDER.ARX:    AutoCAD Render program executable


Incompatibilities and Limitations
=================================-

Image Clipping when Rendering to a File
---------------------------------------
To ensure accurate image representation when rendering to a file, the
selected image resolution must match the size of the viewport being
rendered. If these values are not the same, the image will be clipped.
Use the SCREENSIZE command to check the size of the current viewport.
If you are working with multiple viewports, be sure that the desired
viewport is selected when you use the SCREENSIZE command. You can
change the size of the viewport to match that of a specific image
resolution, or enter the viewport size as a User Defined resolution.


Fatal Errors
------------
In the event of a fatal error, Render attempts to shut down. Due to an
AutoCAD limitation, the Render/AutoVision applications can't unload
themselves, and the user must use the (arxunload "render") function.


Paper Space
-----------
You cannot render models in paper space. If you are in paper space and
attempt to invoke the Render command, the following message is
displayed:

    ** Command not allowed in Paper space **


Color Wheel
-----------
With some display cards, there is a problem with the color wheel that
appears in various lights and materials dialogs. The wheel
inappropriately turns gray at times. If this occurs, please cancel the
dialog and re-enter. Also, if you use the slider or edit boxes, you
can ignore this problem. In any case, the numeric values are correct.


Color Selector
--------------
The color selector displays only the slider bars (not the color wheel)
when R13 Render is configured for rendering to a separate display, to
a full color display, or to hard copy.


3D Studio and Render
--------------------
R13 Render does not support texture maps. They will be imported and
converted for AutoVision should the user purchase this add-on package.
AutoCAD uses the AVEMAPS environment variable to search for texture
maps.

The file AVEMAPS.PTH acts as an extension to the AVEMAPS environment
variable. This file contains names of directories, one per line, that
will be searched for image files. It must be located on your ACAD
path. This allows you to avoid problems with length limitations of
environment variables on some platforms.

Mesh properties - AutoCAD has no real way to store information at
lower than the object level. For 3DS import, this means any sub-object
level information and everything associated with faces (namely
materials and smoothing) is discarded. Additionally, the edge
visibility is also discarded (all are visible).

3D Studio limits the number of vertices and faces per object to less
than 65535. Using AutoCAD's ACIS solid modeler to create objects it is
easy to exceed 3D Studios limitation. To get around this the user has
several alternatives. One is to split the solids into multiple pieces
in AutoCAD then use the 3DSOUT layer and ACI options to make sure 3DS
objects are under 65535 faces when created. The other option is to use
FACETRES to lower the number of faces generated per object.

All external application data (XDATA and 3D Studio Appdata) is
discarded on both import and export.

3D Studio object attributes are discarded.

3DSOUT does not support AutoVision landscape objects.

3DSOUT does not support AutoVision animation.

3DSIN does not support 3D Studio animation.


Measure Objects
---------------
On new drawings if Measure in the ACAD.INI file is set to 1 (the
default in ACAD.DWG is 0 and ACADISO.DWG is 1) the default Icon Scale
(see Render/AutoVision manual for more information) is set to 25.4
instead of 1.0.


Save as R12
-----------
Attachments by ACI will be lost on SAVEASR12 since this was not a
supported feature of Release 12.


PostScript Output
-----------------
The PostScript output generated by the Render File output feature may
not be readable by all PostScript readers.


WMF and CLP Files
-----------------
Support for WMF and CLP files in the Render/MDI window has been
dropped.


Render to Render Window
-----------------------
When you use an 8-bit Windows driver and select 24-bit Color Depth in
the MDI driver's Options dialog, the colors of images may look wrong.
This occurs because Windows makes a "closest match" of the 24-bit
colors to those in your 8-bit palette. The full color information is
still present, and if you cut and paste the image into a place with
true 24-bit color, the image appears correct.


Rendering to a 32-bit Targa File
--------------------------------
Some software packages require a field in the TGA file header
information to contain the number of bits of alpha present. 32-bit TGA
files created using the Render to File option do not fill in this
information because the TGA file definition is hardware-dependent.

Most software that uses the alpha channel, including 3D Studio and
Adobe Photoshop, function perfectly with AutoVision Targa files. If
you find that the AutoVision renderings to 32 bit TGA files are not
presenting alpha channel information, setting the byte field at 11h in
the TGA file to 08h may work.


Statistics
----------
When statistics is saved in a file, it records the date and time the
rendering was started. The time may not be correct. In that case, exit
AutoCAD and see if timezone is set on your system -- type set at the
DOS prompt and if you see a timezone entry (such as TZ=PST8PDT), reset
it by typing TZ=<return> This should correct the problem.


Rendering AME objects / AMECONVERT
----------------------------------
If you have drawings that contain AME-created objects, use the
AMECONVERT command to convert them to AutoCAD objects before using
AutoVision. You do not have to have AME running to render these
objects. Attached AME material definitions are not brought into the
drawing with the converted objects. Use the RMAT command to attach new
materials to the objects. See your AutoCAD Command Reference for
details on AMECONVERT before using AutoVision or R13 Render.


FACETRES/VIEWRES
----------------
If rendering drawings created in R13 or R13c1, and you notice that the
rendering time increases, you should reduce the values of FACETRES and
VIEWRES. The default setting for FACETRES is 0.5 and the default
setting of VIEWRES is 100.


SHOWMAT
-------
The following AutoLISP code can be used for accessing  the features of
the SHOWMAT command.

(c:showmat (car (nentselp)))  determines the material attached to an
object
(c:showmat #ACI#)             determines the material associated with
an ACI
(c:showmat "Layer Name")      determines the material associated with
a layer


VLCONV
------
The VLCONV command does not work on inserted drawings having Visual
Link data. You must run VLCONV on such drawings, before inserting
them.


Loading RENDER.ARX
------------------
Loading RENDER.ARX as an ACAD.RX entry will result in Fatal Error.
This is because  AutoCAD's display drivers are not yet initialized
when Render is loaded via ACAD.RX.  Its not necessary to place
RENDER.ARX in ACAD.RX since Render autoloads.


Configuration
=============-

AutoCAD Color Configuration and Release 13 Render
-------------------------------------------------
You cannot Render to viewports if AutoCAD is configured for less than
128 colors.


Large Drawings and Windows Swap Files
-------------------------------------
Handling a large drawing that has many faces or a high-resolution
render to file/hard copy/Render Window image might require a very
large Windows swap file. Please consult your Windows manual about how
to increase the Windows swap file size.


Reconfiguration
---------------
To reconfigure your render devices, select the "Reconfigure" option on
the Rendering Preferences dialog box or enter RCONFIG at the Command
prompt. Select your rendering display device, and if you want, select
a rendering hard copy device.

If you change your mind about a device you have just selected, you
cannot reconfigure a second time at this stage. You must exit the
configuration menu and repeat the process. Select "Reconfigure" or
enter RCONFIG, and configure the rendering display and/or rendering
hard copy devices again.


Hard Copy Configuration
-----------------------
Do not cancel during initial hard copy configuration. If you make a
mistake, proceed to complete the configuration and then reconfigure.


Autodesk Trademarks
===================-
The following trademarks are registered in the U.S. Patent and
Trademark Office by Autodesk, Inc.: AutoCAD, Autodesk, Autodesk
Animator, AutoLISP, and AutoShade.

The following are trademarks of Autodesk, Inc.: ACAD, AME, Advanced
Modeling Extension, 3D Studio, Autodesk Device Interface, AutoCAD
Development System, and AutoVision.


Third-Party Trademarks

All other brand and product names are trademarks or registered
trademarks of their respective companies.


=====================================================================-
ASE INFORMATION
===============-

  - ASI Drivers
  - Loading ASE
  - Configuring ASE
  - Editing the ASI.INI File
  - Running ASE
  - Unloading ASE
  - The UNDO Command
  - Links to Block Definitions and References
  - Drawings with Locked Layers
  - Partial DXFIN Support
  - Selecting Drawing Objects with ASE
  - SQL Text Files
  - Character Limit in Dialog Boxes
  - Release 12 Link Synchronization
  - ASEROWS Command
  - Viewing and Accessing New Database Objects Dynamically
  - Running ASE Commands from AutoLISP
  - AutoCAD Link API (ASI Link)
  - AutoCAD SQL Interface (ASI)


ASI Drivers
===========-
New SQL Driver Configuration documents have been prepared for C4.
These documents are in the form of Windows Help files for the Windows
platforms and text files for DOS. Listed below are the drivers
supported.  For DOS you can locate the driver text file in the same
directory in which AutoCAD is installed in.

ASI_DB3        dBASEIII for DOS, Win32s, WinNT, Win95
ASI_DB4        dBASEIV & V for DOS, Win32s, WinNT, Win95
ASI_FXP2       FoxPro2 for DOS, Win32s, WinNT, Win95
ASI_INFX       Informix 4.1 for DOS
ASI_ODBC       ODBC 2.0 for Win32s, WinNT, Win95
ASI_ORA7       Oracle 7for Win32s, WinNT, and Oracle 6 for DOS
ASI_PDX4       Paradox 4.5 for DOS, Win32s, WinNT
ASI_SQL4       SQLServer 4.2 for WinNT


Loading ASE
===========-
There is a new feature in AutoCAD C4, referred to as Zombie Support.
Basically it handles application defined entities when the application
that manages the entity is not present.  For ASE this means that Links
will be managed while ASE is not loaded.  For ASE there are certain
restrictions in Zombie Support. ASE Zombie Support implementation is
listed below.  All cases assume that the drawing contains ASE Links.

OPEN:  A drawing may be open without ASE loaded.  The links will be
activated and accessible when any ASE command is executed.  The
drawing must not contain any xrefs with ASE links.

DXFOUT:  A drawing may be DXF out when ASE is not loaded.  To access
the links on DXF IN you must perform the following steps.

1.  Start ACAD with ASE not loaded.
2.  Perform the DXF IN
3.  Load ASE

Failure to perform these exact steps will result in the links not
being accessible and possible loss of LinkPathName table.

WBLOCK:  ASE must be loaded before wblock of any ASE Linked entity.

XREF:  ASE must be loaded before any xref work can be done with any
ASE Linked entities.

INSERT:  ASE must be loaded before any Insert of a drawing with ASE
Linked entities.

If you are working with a drawing that has ASE Links and you notice
that the links are not accessible, do not save the drawing.  Close the
drawing, Load ASE and re-open the drawing.  Failure to do so, may
cause loss of ASE Link Information.

To load the ASE application you should do one of the following:

+   Enter any ASE command, which automatically loads the application.
+   Use the AutoLISP arxload function, for example, by entering
    '(arxload "ase")' at the command line.
+   Adding the line "ASE.ARX" to the ACAD.RX file automatically loads
    the ASE application when AutoCAD starts. See the documentation on
    the ACAD.RX file for further details on its use.


Configuring ASE
===============-
There are many components which make up ASE.  These components need to
be available for ASE to run. The asi.ini file is installed so that the
character set and collation definition files that ASE requires (as
well as some sample dBase III Plus tables) will be found automatically
when AutoCAD is started from the directory from which it is installed.

If you want to start AutoCAD from a different directory you will need
to make the following modifications to the asi.ini file. Edit the
asi.ini file in a text editor.

Find the Path entry in the [ASI] section.  Modify the ase\lang to an
absolute path. For example, if AutoCAD is installed to c:\r13, the
entry would be Path = c:\r13\ase\lang. This will allow ASE and the
drivers to be able to find the character set and collation definition
files.

Find the [DB3] section.  In that section the entry ASE =
..\com\sample\dbf must be changed to an absolute path. For example, if
AutoCAD is installed in c:\r13 then change the entry to ASE =
c:\r13\com\sample\dbf.

If you receive errors from ASE indicating that it cannot find a file,
you need to check the path entries.


Editing the ASI.INI File
========================-
When editing the ASI.INI file, make sure your editor saves the file as
plain ASCII text. An editor such as DOS-Edit or MS-Notepad is fine.
Some errors have arisen by using the Kedit editor.

If you edit the ASI.INI file and ASE displays the error "asi.ini is
corrupt", you must use a different editor.


Running ASE
===========-

Windows32s
----------
Under Windows, either the DOS Share program (SHARE.EXE) or the Windows
Vshare program (VSHARE.386) must be run before starting AutoCAD in
order to use ASE. These programs should be supplied with their
respective operating systems. If the DOS Share program is used, ARX
applications (including ASE) will not be able to be manually unloaded.
The read-only attribute on the ASE.ARX file may be set to avoid this
problem.

To set the read-only attribute of the ASE.ARX file, select its icon in
the File Manager and press the Alt and Enter keys at the same time.
Then set the attribute with the Properties dialog box.

To install vshare.386 under Windows, add the following entry to the
[386Enh] section of the Windows SYSTEM.INI file:

      device=C:\WINDOWS\SYSTEM\VSHARE.386

The directory path in this entry should point to the location of the
VSHARE.386 file. Windows must be restarted for this to take effect.


DOS
---
Under DOS, the DOS Share program (SHARE.EXE) must be run before
starting AutoCAD in order to use ASE.


Unloading ASE
=============-
Unloading of the ASE Application is now available in C4. There are no
restrictions on when you can unload the ASE application.  When you
unload ASE, no ASE link information will be accessible until the
application is reloaded.

The ASEUNLOAD command is not in this release of AutoCAD. To unload the
ASE application, type (arxunload "ase") at the command prompt or use
the ARX command to unload the ASE.ARX file.


The UNDO Command
================-
At the time of this release, the AutoCAD UNDO command does not always
send internal notification to applications. Therefore, ASE can't fully
support the UNDO command in all circumstances. These are the known
circumstances:

+   If you UNDO after reloading a Displayable Attribute, you must use
    the REGEN command to update the screen.
+   If you UNDO after either synchronizing or erasing Displayable
    Attributes nested in blocks, you should use the ZOOM/ALL command
    (after the REGEN command) to update the screen.
+   The command sequence of XBIND/BLOCK, UNDO is not supported in
    this release of ASE and should be avoided.


Links to Block Definitions and References
=========================================-
When a block is inserted into a drawing, a block definition is
created. If the block contains nested objects with links, then these
links are stored in the block definition. On the other hand, if a link
is made to a block reference (an instance of the block), then the link
is stored with the block reference, not the block definition.


Drawings with Locked Layers
===========================-
ASE does not allow links to be edited for objects on locked layers. In
these cases, ASE displays a Warning dialog box with a message that the
selected object is on a locked layer. The corresponding layer name and
object handle are displayed in the Diagnostic Parameters list box. The
user must unlock the layers before editing the links.

If an LPN has a link to an object on a locked layer, ASE dialog
buttons which manipulate links will be disabled when that LPN is being
used.

When converting AutoCAD Release 12 drawings with links to Release 13
format (with the OPEN command), a warning will be displayed if objects
with links are on locked layers. These links will be erased. The layer
should first be unlocked in the Release 12 drawing before the
conversion if those links are to be maintained.


Partial DXFIN Support
=====================-
Partial DXFIN of objects with links is supported if ASE is first
loaded (BEFORE the DXFIN command) and "identical" LPN's already exist
in the drawing. If the LPN's of the imported objects are "duplicate"
LPN's or if they do not already exist, then the incoming links are
considered invalid and will be discarded.

ASE Displayable Attributes are AutoCAD blocks. Partial DXFIN is not
supported for blocks (and therefore not supported for Displayable
Attributes).


Selecting Drawing Objects with ASE
==================================-
Objects may be highlighted and placed into a selection set with the
ASEROWS and ASESELECT commands. Objects in model space and paper space
are highlighted and selected depending on the current value of the
TILEMODE variable in conjunction with the CVPORT system variable. When
TILEMODE=0 and CVPORT=1, only object in paper space are selected. At
all other times, objects in model space are selected.

In the ASEROWS and ASEEXPORT command, it is possible to specify
selection sets which contain objects from both model and paper space.


SQL Text Files
==============-
SQL statements may be executed from a text file by pressing the File
button of the SQL Editor dialog box (or from the command line option
of the ASESQLED command). The maximum allowable characters per line in
the SQL text file (including the line continuation character '&') is
256.


Character Limit in Dialog Boxes
===============================-
Edit fields have a maximum length of 254 characters in dialog boxes.
SQL statements entered in dialog boxes cannot exceed this limit.


Release 12 Link Synchronization
===============================-
The process of synchronizing ASE Release 12 links may sometimes
require several steps. These steps are initiated by pressing the
Synchronize button in the ASE Administration dialog box or choosing
the same option from the command line. The Synchronize button may need
to be pressed multiple times until the message list is cleared and
full synchronization is complete.

During the synchronization of a Release 12 drawing which is attached
as an external reference to a Release 13 drawing, certain Link Path
Names (LPNs), will be stored in the permanent part of the drawing.
This occurs when an identical link path name is detected in the
external reference. If the xref is reloaded and the content of the
identical LPN has changed, then the links associated with this LPN
cannot be resolved. The external reference should be detached, then
reattach to prevent this from happening.

If the drawing contains over 10,000 links the synchronization process
may hang the computer.  To workaround this problem follow the steps
below.

1.  Load the original drawing in AutoCAD R12
2.  Erase part of the drawing ( use a method such as by layer)
3.  Save the new smaller drawing as a unique name
4.  Repeat steps 1 - 4 until the large drawing is saved in the sum of
    the smaller drawings.
5.  Load each small drawing in AutoCAD R13 and perform Link
    Synchronization
6.  Save the drawing
7.  Repeat steps 5-7 until all the small drawings have been converted
    successfully to R13.
8.  Open a new drawing in AutoCAD R13 and execute Insert/Explode for
    each of the smaller drawings.
9.  Save the new drawing.
10. Conversion Complete


ASEROWS Command
===============-
When using the ASEROWS command from the command line (or
programmatically from an application), only "I" or "_I" should be used
to execute the Insert option of the command.


Viewing and Accessing New Database Objects Dynamically
======================================================-
When ASE initially connects to an Environment, it puts all of that
environment's database object names (catalog, schema and table names)
into memory cache lists to access for better performance. If a new
database object is created (i.e., a new table created with a CREATE
TABLE statement from the SQL Editor or from another user/application
on a network), that table or other database object will NOT be
immediately visible in the popup lists of ASE dialogs or from the
AutoCAD Link API until the memory cache is flushed. In order to view
or access the new database object, you must:

From an ASE dialog or command:
    Select a different superior (upper) database object and then go
    back to view the new one. This will flush the memory cache and
    add the new database object to the database object lists. For
    example, if your current database object settings are
    DB3.ASE.DB3SAMPLE.EMPLOYEE and a new table SALARY was just added
    to the DB3SAMPLE schema, you should pick a "different" schema,
    catalog or environment. The new table will be contained in the
    lists the next time they are viewed. If only one schema, catalog
    and environment are contained in the lists, then disconnect and
    reconnect to the environment.

From the link API:
    Use the function ase_lp_setCurrent() for another environment.
    Then call the same function with the path that is intended to be
    used to get the database object names.


Running ASE Commands from AutoLISP
==================================-
As a rule always have ASE loaded before running an AutoLISP program
which accesses ASE commands. There is an inconsistency in command line
mode password handling in AutoLISP programs.  When ASE is not loaded
program execution will stop at the password prompt in connecting to an
environment.  When ASE is loaded the program execution is
uninterrupted.

The following example demonstrates the place where the situation
occurs.

  (defun inlist ( lst str / ct tmpstr ret )
    (setq ct 0)
    (repeat (length lst)
      (setq tmpstr (nth ct lst))
      (if (wcmatch tmpstr (strcat "*" str "*"))
        (setq ret T)
      )
      (setq ct (1+ ct))
    )
    ret
  )

  (defun c:test( / cmddia )
    (setq cmddia (getvar "CMDDIA"))
    (setvar "CMDDIA" 0)
    (if (not (inlist (arx) "ase"))
      (arxload "ase")
    )
    (command "_aseadmin" "_E" "ora7nt"
      "_O" "_C" "scott" "tiger" "_X" "_X")
    (setvar "CMDDIA" cmddia)
  )


AutoCAD Link API (ASI Link)
===========================-

Supported Compilers (Link API)
------------------------------
This section contains documentation for supported compilers and other
development tools for ADS and ARX applications accessing AutoCAD links
with the AutoCAD Link API for the Windows, NT and DOS386 platform.

For more information on how to create ADS or ARX applications see the
READDEV file.

The following files are provided for developing ASE applications:
ASE.H          AutoCAD Link API main header file.
ASECLASS.H     Class header file if using C++
ASECONST.H     Constant definitions
ASESMP.C       Sample AutoCAD Link program.

Windows and NT Support
MSVC++ 2.1 is supported for both ADS and ARX applications.
To create an ADS/ASE application use ASEATM80.LIB.
To create an ARX/ASE application use ASERTM80.LIB.
See the make include file ASITM80.MAK for compiling.
+   MSVC++ 2.2 will work with the provided libraries.

DOS386 Support
MSVC++2.1 is supported for both ADS and ARX applications.
To create an ADS/ASE application use ASEAPM80.LIB.
To create an ARX/ASE application use ASERPM80.LIB.
See the make include file ASIPM80.MAK for compiling.
+   MSVC++ 2.2 will work with the provided libraries.
+   You must upgrade to Pharlap 7 TNT.  See READDEV for Pharlap 7
    details.

MetaWare High C/C++(TM) is supported for ADS only.
To create an ADS/ASE application use ASEAPH30.LIB.
See the sample profile, ASIPH30.PRO.

Watcom C/C++ 10.x is supported for ADS only.
To create an ADS/ASI application use ASEAPW10.LIB.
See the make include file ASIPW10.MAK for compiling.


ASE AutoLISP API
----------------
For the ase_linkcreate function, when specifying Displayable Attribute
entity parameters (group 8), they should be enclosed into a double
list. For example:

      (ase_linkcreate ... 8 (list '((10 1. 1. 0.) (40 . 1.) (50 .
0.))) ...)


Connection to Environments
--------------------------
Most API functions don't require an SQL-Environment to be connected
with the following exceptions:

    ase_ls_initLpCond()
    ase_ls_initLpDscCond()
    ase_ls_intersectLpCond()
    ase_ls_intersectLpDscCond()


Subentity Selection
-------------------
Using the API, links may be created to subentities such as a vertex,
attribute or polyfacerecord. If the linked subentity is selected, the
corresponding owner object (polyline, insert or polyface) will be
highlighted and/or added to the selection set.


AutoCAD SQL Interface (ASI)
===========================-

Supported Compilers (ASI)
-------------------------
This section contains documentation for supported compilers and other
development tools for ADS and ARX applications accessing external
databases with ASI for the Windows, NT and DOS386 platform.

For information on how to create ADS or ARX applications see READDEV.

The following files are provided for developing ASI applications:
ASIAPPL.H      Main application include file.
ASI.H          C interface
ASICLASS.H     C++ Class interface
ASISDATA.H     Class header file if using C++
ASICONST.H     Constant Definitions
ASIUCODE.H     Unicode Definitions used in ASI
ASICONF.H      ASI.INI Configuration file access
ASISMP.C       ASI sample ADS application.

Windows and NT Support
MSVC++ 2.1 is supported for both ADS and ARX applications.
To create an ADS/ASI or ARX/ASI application use ASIATM80.LIB.
See the make include file ASITM80.MAK for compiling.
+   MSVC++ 2.2 will work with the provided libraries.

DOS386 Support
MSVC++2.1 is supported for both ADS and ARX applications.
To create an ADS/ASI or ARX/ASI application use ASIAPM80.LIB.
See the make include file ASIPM80.MAK for compiling.
+   MSVC++ 2.2 will work with the provided libraries.
+   You must upgrade to Pharlap 7 TNT. See READDEV for Pharlap 7
    details.

MetaWare High C/C++(TM) is supported for ADS only.
To create an ADS/ASI application use ASIAPH30.LIB.
See the sample profile, ASIPH30.PRO.

Watcom C/C++ 10.x is supported for ADS only.
To create an ADS/ASI application use ASIAPW10.LIB.
See the make include file ASIPW10.MAK for compiling.


ASILISP
-------
ASILISP.ARX is now included.  There is also a sample application
located in the ASE/SAMPLE directory.

