Mortal Kombat 1

To activate the Dip Switches press [F10] for setup
at the TITLE SCREEN. In the setup make sure the
[Caps Lock] is on and type DIP. The screen will
change to switch 1, 2 and so on. Once selected the
Dip switches press [Esc], then go to exit & Save.
Now exit the program and come back in, now the Dip
Switches are activated.

Here are what the Dip switches do.
0 - Unknown, affects violence or ???
1 - Blood on/off
2 - Sound on/off
3 - Comic Book Ad on/off
4 - Computer Fatalities on/off
5 - Free Play on/off
6 - Programmer Codes (uses unknown)
7 - Programmer Codes (uses unknown)
8 - CPU Recovers Slowly From Attack (Information from Cheat Machine)