Some kind soul told me that I could change the serial port buffer size
of Zterm via ResEdit. He did not tell me HOW I could change it using
ResEdit, and I have lost his e-mail address.

Could he or any one else please tell me what to do?

I assume that the relevant resource is zSet, but I do not know, and
I have no template for that resource. If you have a TMPL for the correct
resource, I would be grateful to receive it. That way, I could play around
a bit and maybe get my Duo to do something useful with its serial port.
(other than Appletalk).

BTW, I believe that when the port stats says that maximum in buffer is
3074 bytes, that that means increasing the buffer will help, if you are
using hardware handshaking. I can cram text data pretty fast into my Duo,
and can monitor that CTS is being lowered, but the buffer never gets beyond
3074 (out of 4096) bytes. Makes sense to me.