[Rxtx] Re: mac serial sniffing ?

[Trent Jarvi]

On Thu, 20 Oct 2005 pbarthelemy at aim.com wrote:

>> for Windows, I suggest using a tool called PortMon.
>> It is freely available from 
> http://www.sysinternals.com/Utilities/Portmon.html.
>
> Further research on mac serial sniffing have lead me to :
> Serial Port Tool : http://www.versiontracker.com/dyn/moreinfo/macosx/24024
> Portterm : http://kulesh-software.com/Software/PortTerm/
>
> In my case, both are fall short of what I need : I need something on par with 
> PortMon, the soft you pointed me to...
>
>


Years ago when I wanted to reverse engineer the Garmin GPS protocol, I 
just made a custom cable.  I split the rx and tx and sent them to com2 
and com2.  I could then see everything.

computer1 --------------------------> computer2
           <-----------|--------------
                       |  |
                       |  |
Computer3 COM1 <-------  |
           COM2 <---------|



A couple of years after I did that (which was why I started rxtx) I found 
Sun engineers had done a better job in their playground.  It did work 
though.


With the above, you see everything and don't have to worry.  You cant read 
a port and leave the data there.  The obove sends a copy to each computer 
getting around reading the uart and leaving the data.  Observing the 
port is going to need a virtual device or hacking or overriding 
libc/windows dlls while using 3rd party software.  Or the above.