- Maurits Cornelis Escher (Dutch pronunciation: [ˈmʌurɪt͡s kɔrˈneːlɪs ˈɛʃər]; 17 June 1898 – 27 March 1972) was a Dutch graphic artist who made woodcuts, lithographs, and mezzotints, many of which were inspired by mathematics. Despite wide popular interest, for most of his life Escher was neglected in the art world, even in his native Netherlands. He was 70 before a retrospective exhibition was held. In the late twentieth century, he became more widely appreciated, and in the twenty-first century he has been celebrated in exhibitions around the world.
- IBM PC DOS 1.00 (pcjs.com)
PC DOS 1.00 was completed in August 1981 and announced at an IBM press conference on August 12, 1981, when IBM introduced the original IBM PC (Model 5150). It was released on one single-sided (160Kb) diskette, and included 23 BASIC Programs.