Commands are OS-specific; under Windows-NT/95, the command must be a DOS-Box
command (such as "dir" or "nmake").
Under UNIX, it must be a valid UNIX-command (such as "ls -l" or
"make").
The command view keeps a history of commands - you can
select a previous command by pressing
the "Cursor-UP" and "Cursor-DOWN" keys.
(you can of course edit previous commands and execute the modified command
by hitting "Return".)