Hi, Me again... I just separated my questions to different threads... There is strange echo I get by communicating with a pseudo terminal process on MacOSX 10.4 Gambit-Cb14. I open a dummy process that is a pseudo-terminal using the open- process command and when I send data to the port that data gets repeated in the pseudo-terminal output-port. See the example below for better clarity. Can I turn off that echo? I cannot test it on the WinXP platform since open-process is not implemented for (MinGW or Cygwin). Thank you, Francois Magnan --------------------- ; Pseudo-terminal program (define (command-loop) (let ((command (read-line))) (serve-command command) (command-loop))) (define (serve-command command) (pp (list "got command" command))) (command-loop) ; build the above to an executable file called "/tmp/pttest" using gsc and gcc. --------------------- (define (test-pseudo-terminal) (let ((port (open-process (list path: "/tmp/pttest" stderr-redirection: #t pseudo-terminal: #t )))) ;(force-output port) (pp port) (force-output) (thread-sleep! 1) (display "toto\n" port) (force-output port) (pp (read-line port)) (pp (read-line port)) (close-port port))) (test-pseudo-terminal) ; execute the above in a gsi interpreter ; On MacOSX 10.4 I get ; "\33[1mtoto\33[m" ;"(\"got command\" \"toto\")"