It's that same old question and I've read the support forums and there hasn't been a solution yet. I want to stream serial data in from a file to simulate the operation of charactors being send to the micro. I dont want to redirect the input from a COMM port or have the streams assigned in memory. Has anyone tried the SIN command on ARM? My device has 2 serial ports and if I type SIN = 'A' into the command line I get "error 34: undefined identifier". SIN0, SIN1 have the same effect? Thanks, Malcom