[time-nuts] Hyperterminal with variable baud rate
Hal Murray
hmurray at megapathdsl.net
Thu Nov 18 18:37:40 UTC 2010
> Are there any terminal programs out there that allow you to select rates
> other than the standard values?
I doubt if you will have much luck in that area, but please let me/us know if
you find something.
The API from user code to the kernel for the baud rate is usually pick one
from a small set. (At least in Unix/Posix.)
> I'd like to avoid any hardware kludges and hopefully make the fix in the
> terminal software.
Several ideas...
If you are using Linux, you could build your own kernel. Then find the
module for your serial chip and patch the baud rate table so that one of the
normal speeds you don't use would run at the speed you want.
You could also get a PCI card with a serial interface. It will have a
crystal on it, probably in an oscillator package. Change that crystal to
something that fits your needs. That will scale all of the speeds on that
card so it probably won't be useful for anything else.
Another approach would be to get a micro with two serial interfaces and write
a speed-changing program. Since you are working on the raw hardware, you can
set the speeds to whatever you want.
I'm picturing 2 buffers (one each direction) and a big loop that:
Character ready on line 1: read it and put it in the buffer
Character ready on line 2: read it and put it in the other buffer
Space available on line 1 and data in buffer? Send a character
...
You would need flow control in the fast-slow direction, or set things up so
that the buffer is big enough for all the messages you send and your program
(or human) waits long-enough between messages.
--
These are my opinions, not necessarily my employer's. I hate spam.
More information about the Time-nuts_lists.febo.com
mailing list