Abstract: A case shift and lock input mechanism comprising a pair of independently depressable shift keylevers and a depressable shift lock keylever are assembled in a keyboard for actuating a single shift control switch used to condition a printer for printing upper case characters when the switch is actuated. A pivotal bail member is interposed between the switch and each shift keylever for engageably actuating the switch in response to depression of either shift keylever. The shift lock keylever directly actuates the switch when it is depressed to a lock position. A latch device comprising a latch member pivotally mounted on the switch operates to releasably hold the shift lock keylever in the lock position to keep the switch closed for continual typing of upper case characters. The shift lock keylever is released from the lock position through the bail member by subsequent depression of either shift keylever. Each shift keylever actuates the switch independent of the shift lock keylever.