Actually, the hack is to fix the incorrect behavior of the processor in real mode (not lowering line 20 to 0). The fact that it was put into the keyboard contr

Actually, the hack is to fix the incorrect behavior of the processor in real mode (not lowering line 20 to 0). The fact that it was put into the keyboard controller was probably as it is a simple soc[1] with (in the case of a keyboard controller) about 256 bytes of ram and about 1-4K of rom. Which resources was probably still available to the motherboard designers without complicated logic or additional components. It is not the weirdest fix to imagine. note: modern variant of the keyboard controller can sometimes be flashed which is fun to play around with. [1] https://en.wikipedia.org/wiki/Intel_MCS-48 https://en.wikipedia.org/wiki/Intel_MCS-48