Fred Friend wondered..
> i.e. artser.device, 8n1.device etc and wonder whether I should use
> this instead of the squirrel? I bought the squirrel because I was
> told that it was a very fast serial device.
Nope. Don't. In fact, I don't think you can.
The 8n1.device is a special higher-speed version of the normal
serial.device for the internal serial port. I am not sure, but I
think artser.device is a similar thing.
The Surf Squirrel requires the special serial driver
squirrelserial.device to access its hardware. I doubt its the fastest
device driver ever, but its plenty good enough. The Squirrel buffers
serial data in hardware, allowing a much more relaxed cpu polling
approach. The internal serial port requires the cpu to undertake an
interrupt cycle for every byte received or transmitted, which takes
considerable cpu time and interferes with smooth multitasking.
Some people manage to get the internal port running at 115200 baud,
others can barely get to 33600. Even at that low figure, the cpu will
be required to perform around 3400 interrupts per second, which will
seriously affect available cpu time. The Squirrel will happily
sustain 115200 baud at minimal cost in cpu time or multitasking
performance.
All that is but to say: The Surf Squirrel may not be the absolute
fastest serial port for the Miggy, but its very good for general modem
use (most normal modems wont go above 115200 anyway). The other
drivers are attempts to squeeze a few more percent performance out of
the internal serial port, which you don't need to worry about.
Hope that's clear enough to be of some help.
Regards,
Ian
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