[net.micro.atari] atari serial interface review or info wanted

hong@garfield.UUCP (03/06/86)

I want to add an interface for a Hayes compt modem.
And I was told by someone there are a lot of serial interface availiable
, but I have no idea which will suit my requirement.
There are Atari 850, P:R CONNECTION (100 % 850 compt?), U-CALL and
R-VERTER.
Have you used any of the above?
Which one is better?
Thanks in advance.