Pointing devices
Windows 1.0 supported various mice, light pens, trackballs and graphics tablets. Supported interfaces include serial (COM), Microsoft Bus and InPort, and in some versions, IBM PS/2. The latter can be added to any version by using the PS/2 mouse driver from IBM's OEM release of version 1.04.
While use of a pointing device was recommended for a better user experience, it was not mandatory. The environment could be operated with only a keyboard, though some key combinations and shortcuts feel rather clunky today. Windows 2.0 improved this substantially.