On 2014-01-15 22:29, John Wilson wrote: Date: Wed, 15 Jan 2014 18:52:08 -0500 The DHV11 has a pair of 8051s on it. The DH11 is several boards full of logic. It has buffering and DMA capability to offload the host system...it needs much less hand-holding than the DZ11. For *output*. They're all basically identical for input, and that's where you'd actually need help (since you could lose data -- on output you just might get behind). Offloading input processing would need the mux to be close personal friends with the TTY driver in each OS, so I see why it didn't happen, but it would have been *much* more useful. I partly beg to disagree. Any normal usage would typically see at least ten times as much output as input. Input essentially means a user hammering away at a keyboard. Offloading output makes a *huge* difference. But sure, if you could offload input as well, noone would complain. But yes, that has a lot of additional headaches, since OSes tends to want to handle some characters special... Johnny