No pretty icons, no mouse or trackpad; just a black screen with the first line “Starting MS-DOS. . .” followed by the command prompt. That was the interface scheme for the earliest computers, before Apple brought out the graphical version. IBM’s PC-DOS was the very first operating system in the series, loosely based on an earlier Control Program/Monitor (CP/M) interface system. When Microsoft could not come to terms in buying IBM’s version, they decided to make their own, creating the famous MS-DOS operating system.

On this day, June 11, in 1991 Microsoft released MS-DOS 5.0, their response to a rival product released by Digital Research, the DR-DOS 5.0. For the first time, Microsoft including a coding language, QBasic, as well as an on-screen editor.

Microsoft took some heat for allegedly copying much of DR-DOS unique features, but they steadfastly denied the connection. As Brad Silverberg, Vice President of Systems Software at Microsoft and General Manager of its Windows and MS-DOS Business Unit, said in an open letter to PC Week “The feature enhancements of MS-DOS version 5.0 were decided and development was begun long before we heard about DR-DOS 5.0. There will be some similar features. With 50 million MS-DOS users, it shouldn’t be surprising that [Digital Research] has heard some of the same requests from customers that we have.”