"to strike sharply," 1719, probably of imitative origin. The noun is from 1737. The word in out of whack (1885) is perhaps the slang meaning "share, just portion" (1785), which may be from the notion of the blow that divides, or the rap of the auctioneer's hammer.
The human brain: Slip a microchip into snug contact with your gray matter (a.k.a. wetware)/ wetware: the human brain and its DNA code (1980s+ Computer)
[University of Maryland: from hacker] 1. A person, similar to a hacker, who enjoys exploring the details of programmable systems and how to stretch their capabilities. Whereas a hacker tends to produce great hacks, a whacker only ends up whacking the system or program in question. Whackers are often quite egotistical and eager to claim wizard status, regardless of the views of their peers. 2. A person who is good at programming quickly, though rather poorly and ineptly.