Back in the day I had an Amiga 2500/30 with an A2286 as my "swiss army knife" home computer; not only did I have the ability to run MacOS (ShapeShifter) at native speed, but the 8MHz 286 bridgeboard allowed me to do anything IBM PC related. However, I was always disappointed that Windows was dog slow on the A2286. To make matters worse, it felt that whenever disk activity happened via the Amiga-hosted bridge (to a dedicated partition, not a hardfile) the speaker would beep a few times a second.
I remember reading something about the A20 gate not being completely decoded and that there was a hardware fix by simply running a wire between two locations. Simple enough, but unfortunately it ended up frying a board for me so I'm not sure it ever really worked. (Regrettably, I ended up getting another A2286 instead of upgrading to the A2386)
Why was the performance so bad and why did it beep so much?