When did herman hollerit invented the tabulating machine?

Answer

Herman Hollerith invented the tabulating machine in 1890, in order to compute the results of The United States Cense for that once. Six years later he founded the company "Tabulating Machines Corporation" wich would become the IBM (International Business Machines).

The big technologic done of his machine was the revolutionary use of punched cards. The cards were punched (little holes) in predetermined locations wich would allow compute the cense informations more rapidly and easily, with less chances of errors.

Each people registered by the cense have had one card associated to him. Each specific location in the card reffered to a specific information of the person. So, the holes in the card determined the several information for each people consulted.

The cards were inserted automatically into the machine, one by one. For each one, a lamp located under the insert tray emmited a light flash through the card against light sensors, one for each hole location. (*)

In this way, only the sensors corresponding to the holes was estimulated. And so, only these lighted on sensors was able to register a pulse, wich would increase the corresponding counter by one, for that specific information.

That technology had decreased incrediblely the time spent for the cense results computing.

(*) (some people have a different thinking about the holes "reading" process. Their oppinion is that the reading process was made not by a light estimulation, but an electric one, by the contact of steel brushes instead of sensors with a steel plate instead of a lamp).

First answer by Fernando Ma. Last edit by Fernando Ma. Contributor trust: 4 [recommend contributor]. Question popularity: 5 [recommend question]