I manage to salvage the corrupted zip from wayback machine and put it to work under DOSBox. The same setup also runs under QEMU, but DOSBox superior graphics subsystem put QEMU to shame on the performance.

Ah... what a nostalgia.

Another...

I suppose that sort of program really benefits from running on a fast machine under dosbox. Nice pics btw. Is that a dos or early windows program? I'm supposing windows.

It's AutoCAD R13 DOS + Vibrant SoftEngine 3.74 DOS.
In the days of AutoCAD DOS, the ADI display drivers were what making the day and night experience and productivity. I still remember my 1997 Matrox Mystique shipped with DynaView ADI driver as a differentiator to most cheaper S3/Cirrus OEMs which mostly bundled Panacea TurboDLD ADI driver.

I suppose that sort of program really benefits from running on a fast machine under dosbox.

Not quite. The machine I have is more than 5 years old. Core 2 Duo E8400 Win7 32-bit 3GB RAM + GeForce 9400 IGP. It is 3X faster than SoftEngine referece system in the past (1996-1998), which was an Intergraph Graphics Workstation based on P90 + 64MB RAM and Diamond Viper PCI.

Obviously, if you have a more powerful machine, such as Core-i5/i7/AMD FX/Kaveri APUs, you get even better performance.

What exactly does Soft Engine do for AutoCAD?

I've been using AutoCAD since release 10 and never heard of it...

It is a software accelerator and productivity enhancement add-on for AutoCAD R11,12 and 13 DOS. You can use Internet Wayback Machine to check it out at http://www.vibrant.com/

The Windows version is less appealing compared to the enhancements the DOS version brought into the picture. No doubt, eventually the company was bought over by Autodesk as AutoCAD R14 ended the DOS side of the story.