IBM announced the Type 805 Test Scoring Machine in 1938. Tests to be scored by the machine were answered by marking spaces on separate answer sheets which had a capacity of 750 response positions, or 150 five-choice or 300 true-false questions. The answer sheets were dropped into the 805 for processing.
Inside the 805 was a contact plate with 750 contacts (electric fingers) corresponding to the 750 answer positions. Each contact allowed one unit of current to flow when a pencil mark was pressed against it. A scoring key separated the contacts into two groups, the "rights" and the "wrongs." When an answer sheet was inserted, an amount of current equal to the total rights and total wrongs was allowed to flow. When the operator manipulated the controls, the 805 indicated the scores.
