How did MS-DOS decide that two seconds was the amount of time to keep the floppy disk cache valid?
https://devblogs.microsoft.com/oldnewthing/20190924-00/?p=102915 [devblogs.microsoft.com]
2019-09-25 02:12
Mark Zbikowski led the MS-DOS 2.0 project, and he sat down with a stopwatch while Aaron Reynolds and Chris Peters tried to swap floppy disks on an IBM PC as fast as they could.
They couldn’t do it under two seconds.
A followup: https://devblogs.microsoft.com/oldnewthing/20191001-00/?p=102946