Jack Erbes wrote in news:mPidnfR-_vQresTfRVn-
:

As an added note, someone on another group pointed out to me that
Hyperterminal will not always work as I described it. It will work for
receive only connections but if the sending device expects that there
will two way communications it will not or may not work. I'm not that
smart about RS-232 communications and can't further explain that but it
sounds reasonable to me. Nothing else in Windows is guaranteed to
always work, why should that? :)


Those problems are usually because of the hardware connections associated
with CTS (clear to send) and RTS (request to send) lines not being held
high. RS-232 is made for hardware handshaking between devices so the
listening device can stop the transmission when its buffer (bit bucket?) is
full. It goes way back to really dumb terminals that have no storage in
them for data. Jumpers added to the DB9 or DB25 connectors can make it run
wide open to hyperterm on dumb data....er, ah, like NMEA..(c;

http://www.aggsoft.com/rs232-pinout-...and-signal.htm

http://www.aggsoft.com/rs232-pinout-cable/
Aggsoft has a serial port monitor and a data logger you can download and
try for free....

http://www.connectworld.net/rs232.html

And, for you boys and girls, Mr Rogers has a website:
http://www.routergod.com/misterrogers/

The other problem is Com1 and 3 use IRQ 4 interrupt while Com2 and 4 use
IRQ 3 interrupt. If the Com1 serial mouse is attached, putting your data
on Com 3 will make it all go crazy.
http://www.bbdsoft.com/rs232.html

http://www.zytrax.com/tech/layer_1/c...tech_rs232.htm