On This Date in Minnesota History: September 15

September 15, 1998 – Minnesota native, University of Minnesota grad and American inventor, Reynold B. Johnson, died on this date in Palo Alto, Calif. “A long-time employee of IBM, Johnson is said to be the "father" of the disk drive. [His] other inventions include automatic test scoring equipment and the videocassette tape.” In 1996, Johnson was awarded the Franklin Institute's Certificate of Merit.

http://en.wikipedia.org/wiki/Reynold_B._Johnson

Reynold B. Johnson

http://www-03.ibm.com/ibm/history/ibm100/us/en/icons/testscore/team/