Serial Ports on Windows

I created this page in case some people may have some questions or answers about [using a serial port] on Windows.

I just tried to communicate with com1 on a Windows 2000 machine.  For some reason I could not receive any data using the following commands in Wish.
   % proc rd_chid {chid} {
   set msg [gets $chid]
   puts $msg
   }
   % set com [open com1: r+]
   % fconfigure -mode 9600,n,8,1 -blocking 0 -translation auto -buffering line
   % fileevent $com readable [list rd_chid $com]

However, I was able to receive data by putting those last 3 lines into its own procedure...

   % proc rd_chid {chid} {
   set msg [gets $chid]
   puts $msg
   }
   % proc open_com {} {
   global com
   set com [open com1: r+]
   fconfigure $com -mode 9600,n,8,1 -blocking 0 -translation auto -buffering line
   fileevent $com readable [list rd_chid $com]
   }
   % open_com
   # lots of data comes streaming :)
   % close $com
jg

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Tcl 8.4 greatly improved serial port control across platforms.  Refer to the updated [fconfigure] documentation for more info.

----
To retrieve details on input/output errors--which are, in general,
frequent, when working with serial lines--interrogate
    set details [fconfigure $serial_handle -lasterror]
8.3.4 introduced this capability.


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How can I connect to a com port higher than 9?
(I am using a terminal server, and its driver creates com ports upto 16 or so.)
Would appreciate answer by mail - anner@flexlight-networks.com

Thanks.