It was quite a chip. In the early 90's I had built a computer from scraps from school, a 386/40mhz IIRC. It was ok but a bit weak, at some point I came across a 486/40 and motherboard (both AMDs I think).

It was a beast in comparison, even complex calculations I printed just went off the screen faster than could be read. Screen became a blur, Turbo Vision Pascal and C++ just screamed on it. Instant response.

As mentioned on the site many times, my modern laptop doesn't feel appreciably faster, though the graphics are a lot prettier.

Compared to 386DX40, 486DX66 was a helluva strong horse.

Of course, me being 18 or so was mostly interested in FPS of games like Duke Nukem or Doom.

30 years and it's still hard to emulate using software or FPGAs.