Serial: Echoing characters

5 //
6 // "Simple serial echo test. Echo what we receive back to the sender"
7 //
9 // "9600 baud, no parity, 8 bits, 1 stop bit, hardware handshaking"
10 SERIAL 9600,N,8,1,H ONREAD GOSUB 100
20 RETURN
100 // "Subroutine called when we recieve a character"
105 READ #SERIAL, A
110 IF A != -1
115  WRITE # SERIAL,A
117  // "Keep reading until we get -1 (no more characters waiting)"
120  GOTO 100
130 END
140 RETURN