I know that this bit is supposed to give 0 or 1 depending on the Clock Select of the Misc Output Register, essentially the reversed value of the bit given is set. In Dosbox this bit gives 1001, which is supposed to be reversed(xor 15/0xF) for the switches.

What do each of the four switches mean? What do the 1 and 0s(The switches actual values, so 0110 in the case of Dosbox).

What does each bit represent? What does it mean when bit 0-3 (isn't) set?