How do federal laws require employers to treat those with disabilities?

No discrimination. The laws basically try to make it fairer for those with disabilities to work. For example: jack is good with computer and has no disabilty, and joe is also good with computer but he has no legs--must use wheelchair. Joe can do all the computer work just as well as jack can--so, the law requires that company hiring jack/joe provide ramp access/elevator so joe can get to work. Hope that makes sense.