Command:   sync - flush the cache to disk
Syntax:    sync
Flags:     (none)
Example:   sync                     #  Write  out  all  modified   cache
                                      blocks

     MINIX maintains a cache of recently used  disk  blocks.   The  sync
command  writes  any  modified  cache  blocks back to the disk.  This is
essential before stopping the system, and should be done before  running
any a.out program that might crash.