read a file
[line]r [filename]
This command reads in the contents of a file and appends it immediately following the line line. If a filename is not given, the current file is used. If line is omitted, it will append the file after the current line.
The Read command must be the last command on a line.
The Read command can not be used inside a Global (g) or Until (u) command.
Set to the address of the first line read from the file.
Not affected.