Hi,
My apologies for not answering earlier. I didn't know of the existence of this mini-forum and did not receive any notifications for new posts!
Yes, this should be possible. Linux on you laptop does not expose the DE1-SoC as a whole and you can access just the serial port (this is what minicom does). Under linux a serial cable connected to the board appears as /dev/ttyUSB0 in the file system and you should be able to stream a file through it if you want (beware that it can be quite slow if your file is large!)
The link below shows how to do this for a serial connector called /dev/ttyS0, but technically you shouldbe able to use the same technique with /dev/ttyUSB0 to write to the board.
https://stackoverflow.com/questions/8877269/writing-to-serial-port-from-linux-command-line
