"David Harper" wrote in message
m...
Ok, I have one more additional question. :-)

Sorry, I skipped something on the previous response.

I answered for ASYNCHRONOUS serial such as RTTY or async ASCII.

Some protocols, such as packet, use SYNCHRONOUS serial. Synchronous serial
is a lot harder to receive. There are no start and stop bits, so the
protocol doesn't involve that part of the overhead that async uses.

There are several synchronous protocols, but they mostly involve two
characteristics.... first, there is some mechanism for the receiver to
recover the clock. Frequently, the clock is embedded in the data, although
is could be sent over another channel. This allows the receiver to know the
bit boundaries. Every so often (typically every data packet) a special
pattern is sent that allows the receiver to identify the character
boundaries. In the common protocols, such as X.25 (or AX.25), there is also
a prohibition against sending too many of the same bit in a row. Special
procedures are invoked if this happens in the data.

...

Thanks for all the great information guys.. that helps a lot...

So, where can I get a good comm program that has RTTY capability
(ideally freeware, to get started with) for my computer?

Thanks!
Dave

In article ,
David Harper wrote:
So, where can I get a good comm program that has RTTY capability
(ideally freeware, to get started with) for my computer?

You couls start with a google search for "rtty12g" which is a very
old program written in BASIC to run under DOS. That's a program I
have used to make a TTY machine play in a museum situation.

Or there's the modern free MMTTY program, which is intended for running
RTTY on the air, but it has an output to FSK key the transmitter and you
can use that to drive a TTY machine (through a suitable driver circuit
of course) What it doesn't do, and I wish it did, is while receiving
to output "cleaned up" TTY signals so they could go to a printer.
--

jhhaynes at earthlink dot net

So, where can I get a good comm program that has RTTY capability
(ideally freeware, to get started with) for my computer?

Go here for sound card programs. As mentioned mmtty is very good to start
with for rtty.

http://www.muenster.de/~welp/sb.htm#zvei

Here is another place to checkout. It mentions packet, but the interface is
for all sound card modes.

http://www.packetradio.com/

In article ,
David Harper wrote:
So, where can I get a good comm program that has RTTY capability
(ideally freeware, to get started with) for my computer?

You couls start with a google search for "rtty12g" which is a very
old program written in BASIC to run under DOS. That's a program I
have used to make a TTY machine play in a museum situation.

Or there's the modern free MMTTY program, which is intended for running
RTTY on the air, but it has an output to FSK key the transmitter and you
can use that to drive a TTY machine (through a suitable driver circuit
of course) What it doesn't do, and I wish it did, is while receiving
to output "cleaned up" TTY signals so they could go to a printer.
--

jhhaynes at earthlink dot net

So, where can I get a good comm program that has RTTY capability
(ideally freeware, to get started with) for my computer?

Go here for sound card programs. As mentioned mmtty is very good to start
with for rtty.

http://www.muenster.de/~welp/sb.htm#zvei

Here is another place to checkout. It mentions packet, but the interface is
for all sound card modes.

http://www.packetradio.com/

Thanks for all the great information guys.. that helps a lot...

So, where can I get a good comm program that has RTTY capability
(ideally freeware, to get started with) for my computer?

Thanks!
Dave