READCHARS num
RCS num

	reads "num" characters from the read stream and outputs those
	characters as a word.  If the read stream is a file, and the end of
	file is reached, READCHARS outputs the empty list (not the empty
	word).  If the read stream is a terminal, echoing is turned off
	when READCHARS is invoked, and remains off until READLIST or READWORD
	is invoked or a Logo prompt is printed.  Backslash, vertical bar,
	and tilde characters have no special meaning in this context.