> Since this is 1983, he's obviously talking about IBM PCs[1] and DOS[2] More likely, he was talking about CP/M, Commodore's C64 or earlier systems, Apple II,

> Since this is 1983, he's obviously talking about IBM PCs[1] and DOS[2] More likely, he was talking about CP/M, Commodore's C64 or earlier systems, Apple II, or mainframe/midrange terminal systems including Unix since > it was not until 1984 that IBM PC and clones became the dominant computers [1]. [1]: https://en.m.wikipedia.org/wiki/Influence_of_the_IBM_PC_on_the_personal_computer_market https://en.m.wikipedia.org/wiki/Influence_of_the_IBM_PC_on_t...