Cardco was started in 1982 by Ed Lippert and Breck Ricketts out of a garage in Kansas with four employees. Breck designed almost all of the products and Ed was the energetic salesman. The company grew too quickly and lacked necessary maturity. For example, on Tuesday, February 19, 1985, a U.S. federal trademark registration was filed for Cardco by Breck. The USPTO had given the Cardco trademark serial number of 73522548. By November the federal status of this trademark filing was ABANDONED-FAILURE TO RESPOND OR LATE RESPONSE. The business collapsed by 1989. Manufacturing rights were sold off and the founders went on to pursue other business ventures. More information can be found here: http://www.pcmuseum.ca/companyprofile.asp?id=50
The most valuable feature of the Cardboard/6 is its ability to switch select memory address lines on a per slot basis. You can right-click the document on the left and download the full instruction manual. In addition to this expansion unit, I also have a page to discuss the Cardco numeric keypad. To the best of my knowledge this information is not available anywhere else online today.
