My 386 didn't have a color graphics adapter, which required using a program called "Phix" - a terminate-stay-resident that emulated VGA on monochrome. Sadly this completely broke QBASIC (the editor was just a black screen), so I had to reboot the machine (to remove the TSR) in order to hack on GORILLAS.BAS. Compilation times nowadays are still longer than that rigmarole.
Hercules definitely rings a bell. The Wikipedia page[1] actually explains how the TSR [probably] worked, which seems to not be much as the Hercules seems to be quite elegantly designed.