My guess: ACAD 2.0
My intro to AutoCAD was two years later (i.e., 1987) -- V 2.6, just before they changed the numbering system (the next version was 9.0). The platform was a PC/AT 286 running DOS 2.0 at 12 Hz (!!!), with a 200 Mb hard drive. I was working for a consulting engineer at the time who had one HP pen plotter ("E-size" paper and mylar). We sneaker-netted the plot files to it via floppy.
On a text-heavy drawing, like an equipment schedule, I could go outside and smoke a cigarette in the time it took my PC to regen for a plot file... so I usually did.