Today in 1979, RadioShack released the TRSDOS 2.3, an operating system for their Tandy TRS-80 microcomputers. Although short-lived, many of its ease-of-use commands did serve as a minor inspiration for Microsoft's MS-DOS, along with CP/M, an operating system developed for Intel 8080/8085-based microcomputers.   Image Credit: TheOldComputer.com