The VT180 "Robin" version of Kermit-80 operates "generically", i.e. uses
only CP/M calls, and does not do its own device or interrupt handling.  It
can keep up just fine on 4800 baud systems, BUT... there's no way to send
a ^S (XOFF) from the keyboard -- the firmware swallows it, and uses it to
stop the screen without telling the host (which continues sending).  So to
send a ^S to the host from the keyboard, you must type the left-arrow key.

An older version of KERMIT, 3.1, supported the VT180 by direct use of the
hardware interrupts.  The source for this old version is still available as
CPMBASE.V31.  However, that version lacks many features which were added in
later versions, and has many bugs that have since been fixed, so the newer
version based upon CPMBASE.M80 should normally be used.