To give you some expert insight from the guy who did the Linux
driver :-)
The newer drivers (i.e. baycom_ser_fdx in the 2.1.x series) use
the Delta-CTS interrupt, that is, if the CTS line (which is connected
to the receive data output of the modem chip) changes, you get
an interrupt. The interrupt then reads a time stamp counter and
updates its PLL and feeds the received bits into the HDLC decoder.
So worst case you get one interrupt per bit, on average it's less.
Although I wouldn't recommend this, people used the driver successfully
up to 9600 bauds.
> I am still kind of leery of this approach, If you can recompiling the
> kernel while using the modem I would say its OK. I guess I am just
> skeptical. I do plan on buying one so I guess I will find out sone
> enough.
You don't even need to buy one to find out :-) The new driver
(baycom_ser_fdx) is full duplex capable, as its name implies.
Tie the DTR and the CTS pins together and use it as a loopback
interface.
BTW if you're using IDE disks, you should hdparm -u1 all your disks,
otherwise the IDE driver will disable interrupts for disgustingly
long periods of time, which will make the baycom driver fail.
Tom