Complex sentence: Companies modified their computers' BIOS to work with newly discovered incompatible applications, and reviewers and users developed stress tests to measure compatibility; by 1984 the ability to operate Lotus 1-2-3 and Microsoft Flight Simulator became the standard.
Split into simpler sentences: Companies modified their computers' BIOS to work with newly discovered incompatible applications. Reviewers and users developed stress tests to measure compatibility; by 1984 the ability to operate Lotus 1-2-3 and Microsoft Flight Simulator became the standard.