Hi,
I too am now playing with serial ports, both on my Mac at home and on 
a Windows 2000 machine at work...not having a whole lot of luck so 
far although I have managed on W2000 when the ports are connected by 
a null modem cable, to read on com2 what I've sent out on com1. So 
far am unable to similarly read from an external device.
Can you give me any tips? Especially on my Mac as that is what I'm 
working on at the moment.
Which is port 1 on Mac, the modem or the printer? Port 1 seems to 
open ok, but port 2 gives a primitive failed error.
I see that your change set appears to be in the image (3.1Alpha4332).

What I'm basically attempting to do at work is continuously read from 
an external device, splitting into different streams (displayed on 
separate windows) depending on a character received with the high bit 
set. eg if I receive a char hex 80, the following chars will get 
displayed on one window until an different char eg hex 81 gets 
received wherupon the following chars will get displayed on a second 
window. The intent is to be able to differentiate which part of the 
program, different debug statements are coming from via one port on 
an instrument.
Thx for any and all help.
   Ken

At 20:04 -0400 on 2000/06/27,  David N. Smith \(IBM\) is rumored to 
have written:
>Hi:
>
>I've been playing with serial ports on my Powerbook G3 and I 
>discovered some not so nice actions in class SerialPort. If the port 
>is in use elsewhere, trying to open it gets a Primitive Error.
>
>I'd rather have my code get back some indication that the port 
>didn't open, so I made some small mods to SerialPort, which are 
>attached. Basically, primitives used during open answer nil if they 
>fail, and the open method answers nil also.
>
>Dave
>Attachment converted: hd7600:SerialPortChanges.1.cs (TEXT/R*ch) (0001AA45)
>_______________________________
>David N. Smith
>IBM T J Watson Research Center
>Hawthorne, NY
>_______________________________
>Any opinions or recommendations
>herein are those of the author 
>and not of his employer.