DOS6.22, Autocad Release 11 and VESA drivers

This is a simple How To webpage (dated Dec 2005) that shows you how to configure Autocad Release 11 for DOS on the latest PCs in hi resolution modes (800x600, 1024x768 and 256 colors).

I expect that you already know how to use Autocad Release 11 for DOS and have it running at the default 640x480 VGA mode and wish to run it at a higher resolution.

WHY bother?

I work in a polytechnical institute and one of my microprocessor labs had their PCs upgraded to PII 400 Mhz machines. The only programs we ran were DOS based communication programs like Procomm+ so that we could talk to the microprocessor development systems. Previous to the upgrade, we were running 286 20 Mhz machines.

Well, the old slow DOS programs literally flew when we ran them. They ran faster than any new program on the latest Windows version. So I tried some older programs that I had - one of which was Autocad Release 11 for DOS. It runs amazingly fast!

It renders 3D drawings instantly! I've compared it to Autocad 2000 running on a Pentium 4 at 2 GHz and guess which one redraws faster? The DOS version running on a PII at 400 MHz does! Complex 3D drawings in multiple view windows pop instantly on to the screen. You cannot see the vectors being drawn.

If you want speed in Autocad, go back to the old DOS version Release 11.

Graphic Resolution Modes

The first problem that I ran into was that Autocad Release 11 did not support the latest PCI or AGP cards. Out of the box it ran in 640x480 mode - not acceptable. So I had to find an alternative. All video cards since about 1995 support the VESA standard which supports all high resolution modes like 800x600 and 1024x768 and higher. The video cards directly interface to a program that has VESA driver support. You do not need to run a VESA TSR (terminate and stay resident) driver specific to your video card. This was a problem prior to 1995 or so.

NOTE: Before you go any further. Make sure that you can run Autocad in DOS on your PC in 640x480 VGA mode. If you can't do this then you're wasting your time if you hope that any of the following will help you.

SVADI

SVADI is a program that interfaces the Autocad Driver Interface to super VGA graphics mode. It is a TSR that must be run before Autocad is started. SVADI is an old program that again doesn't support any new video cards directly but it does support the VESA standard!

The key to making Autocad work in high resolution mode is to configure the SVADI program for a VESA VGA driver! It is simple but took a lot of work to figure out.

Configuring DOS for Autocad Release 11

The first thing that you must do is download the SVADI.ZIP file located here. This zipped file contains all the video related files required to run Autocad Release 11 for DOS in high resolution mode. The files are:

Make a new directory on your c: drive called ADI and uncompress the contents of svadi.zip to it.

Here's my config.sys file for running Autocad Release 11:

FILES=99
buffers=20
stacks=9,512

Here's my autoexec.bat file for running Autocad Release 11:

PROMPT $p$g
PATH C:\DOS;c:\pkzip;c:\acad
SET TEMP=C:\temp
set dspadi=\adi\adidisp.exp
\adi\svadi
c:\mouse\mouse
cd\acad
acad

Notice that the adidisp.exp file is pointed to by the Autocad dspadi variable. This lets Autocad know where to find the adidisp.exp file. Also note that the svadi program is run from the autoexec.bat file.

Configuring SVADI

NOTE: You must be able to boot to DOS in order to run Release 11. There are many websites that show you how to make a dual boot PC - dual booting is beyond the subject of this website. You need to be able to boot to a "previous version of DOS:

Go to c:\adi directory. Run the SVADI configuration program:

c:\adi> svconfig

You may have to unload the SVADI program first by runnning :

c:\adi> svadi -u

Go to "Resolution/Mode of Graphics Screen" menu choice. Select "VESA VGA" for the Card Type and the appropriate resolution 800x600, 1024x768 or 1280x1024 and the number of colors 16 or 256. I've tried 1280x1024 with little success with my AGP 32 MB Nvidia card. The cursor and pull-down menus screw up after a little while.

Go to the General Configuration Values menu and select Interrupt Vector 7A for the Display and Rendering settings. Save the configuration and exit.

Configure Autocad for ADI 4.0

Go to the c:\acad directory and run autocad by using the "acad" command. Select 5-Configure Autocad, select Video Display and select ADI Display V4.0 or V4.1 both appear to work equally well. Save and exit. Load a drawing and watch Autocad fly!

Troubleshooting

The one major problem that I had was with the CMOS setup settings for the video card. Autocad first came up and it ran super slow like molasses - totally pathetic compared to 640x480 mode (benchmark). I eventually figured out that I had to disable all the shadow RAM settings concerning the video card and pretty well anything to do with the video card settings in the CMOS setup. Then it worked great!

In the likely event that I have forgotten a step concerning configuring SVADI and it doesn't work, you may email me at

.

Please note: I will not provide any help on using Autocad or configuring it for anything else except what has been indicated on this webpage.