900 is the frame number you wish to copy. (valid numbers range from 0 to
1843)
local_frame_900.yuv is the name of the file on deuce.
Press the help button. The command you want to use is
scp diskus:$i.yuv /Your_directory/$i.yuv
iterate allows you to specify the range of values substituted for $i - see the help menu for iterate.