In 1990, Microsoft and IBM focused on developing OS/2, a strategic PC operating system that offered advanced features like Presentation Manager GUI and HPFS file system. The pre-release of OS/2 2.0 showcased a hybrid system with a mix of 16-bit and 32-bit components. Surprisingly, this version gave a glimpse of the future with 32-bit flat model programming and multiple DOS sessions in windows. However, bugs in DOS boxes and LAN Manager setup were notable issues. The OS/2 2.0 SDK included a 32-bit C compiler and extensive documentation, paving the way for early 32-bit application development. This pre-release version hinted at a future that could have changed the course of operating system history.
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