Date   : Wed, 08 May 1985 17:16:44-EDT
From   : Mike Chepponis <Michael.Chepponis@CMU-CS-C.ARPA>
Subject: Kaypro II at high baud rates

I have been using my Kaypro II ("old" style) at 19200 baud regularly for about
two years now.  In addition, I never need to use the flow control characters
^S and ^Q, so EMACS works without key rebindings.

It's true that you need to write your own terminal emulator which is interrupt
driven.  Incoming characters cause an SIO interrupt so even if an "expensive"
operation is happening, like clearing the screen, the character is grabbed and
stuffed into a circular buffer.  The queued-up characters are processed when
the "expensive" operation completes.  I also bypass the ROM screen handling
routines and write to video ram directly. (Apparently on the "new" 2 and 10
the video controller chip limits the thruput to something around 9600 baud or
less, even when you write software to drive it and bypass the ROM.)

The Kaypro II hardware can operate at high baud rates; too bad standard
software doesn't bother to do it.

-Mike