Somewhen around 1988 our family were the proud owners of a 12 Mhz AT 286 from Laser. It had an EGA adapter, I think it was from Cirrus Logic as well. Like the picture above, it had dip switches to configure its behavior; when the machine arrived it was set to 'auto' mode (according to the sparse documentation), whatever that meant.
We'd been using it for several months, playing games like Police Quest and Test Drive and the like, when one evening something weird happened. Upon startup of Leisure suit Larry, I noticed the screen rendering speed was greatly increased, and gameplay was much more fluent. Remember, we thought the speed before the change was normal for the type of machine. Unfortunately, after a first reboot (common in those days) the speed increase was gone. So we went on trying to find the cause of the speedup. Only after several days, we found out what the cause had been; Paratrooper. No idea - still - what was exactly so special in that game that it caused 'something to change' in the graphics adapter, but it worked; all EGA games started after Paratrooper got a significant speed increase. So much so, that after we found out, paratrooper was installed in autoexec.bat! Luckily, the game could be exited very easily (ESC). Believe me when I say I know that game's intro tune.
By the time we started thinking of buying a new machine (think it was 1993 or so) I experimented with the before mentioned dip switches a bit, and found out that the 'EGA' mode configuration setting was speedy and didn't 'require' Paratrooper... 😳 😁
I also think back in horror of the times VGA games came to market that weren't supporting older standards like EGA or CGA. Just hearing adlib music with a black screen is not funny. 🙁
On a sidenote; the games Star Goose! and F29 Retaliator did weird things on that computer as well, triggering a crazy speedup of the system's internal clock (sometimes very handy). I don't know if they do the same for other systems besides that much beloved - and dreaded - 286. 😊