On Mon, 2007-03-05 at 18:03 +0000, Ralf Baechle DL5RB wrote: > A few people asked me if it is possible to drive one of those RS232 abusing > modems through a USB-to-RS232 converter but I guess the answer is no?
No way. For 9k6 you're polling the RX line say every 25us. That's just not feasible over full speed USB. I'd expect most of these cables to allow modem status line sampling over USB only once per USB frame, i.e. once per 1ms. OTOH, if you manage to change the firmware of such an adapter (also not very feasible, because normally it's mask rom), then you can have a "non dumb" modem ;-) If someone has the time one could probably adapt something like a Silabs Toolstick http://www.silabs.com/tgwWebApp/public/web_content/products/Microcontrollers/en/USBToolStick.htm to drive a Baycom type modem, they're about the same price as an USB to RS232 adapter... Tom - To unsubscribe from this list: send the line "unsubscribe linux-hams" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
