VT52  is  a VT52 terminal emulator written for Kaypro II and  IV  (non-
graphic versions).  It contains the following features:


               1) Interrupt driven
               2) 256 byte receive buffer
               3) automatic flow control
               4) direct to video emulation of VT52
               5) Supports application keypad
               6) Baud rate programming
               7) Break and null generation
               8) Additional escape sequences to support EMACS

     Because  of 1 through 3,  VT52 is able to run at high baud rates  (I've 
used 1 it at 4800) without losing characters.   This is true even on non-sped 
up Kaypros.

     Because  of  4,  VT52 does a much better job of emulating a  VT52  than 
other  programs that only translate VT52 escape sequences into Kaypro escape 
sequences (for example reverse line feed on VT52).

     Keypad  application  mode  is selectable via  the  normal  VT52  escape 
sequences received from a host computer.   The keypad on the Kaypro does not 
have all the keys necessary to map into the VT52 keypad,  so I had to choose 
which keys to map where (see KAYPRO.KEY).   The only key that is lost is PF2 
(normally  the help key) and this can be mapped to a control key when in  an 
editor such as VAX's EDT.

     All features such as baud rate selection,  break generation are invoked 
in terminal mode of VT52 by typing ^\ followed by the appropriate key.   For 
a list of the commands, type ^\ ? in terminal mode.

     The  escape  sequences  that VT52 has in addition to  the  normal  VT52 
escape sequences were chosen to allow a much faster screen edit using EMACS.  
The escape sequences are:

                    ESC @ 1        - Insert space at cursor (cursor stays)
                    ESC @ 2        - Delete character at cursor
                    ESC @ 3        - Insert line at cursor line
                    ESC @ 4        - Delete line at cursor line

     There  are  some area's that still could be improved  in  VT52.   Since 
source is included,  I invite anyone to do so.  At present, VT52 does not do 
auto  wrap.   It  acts like a VT52 with auto wrap off (cursor stays in  last 
column).  This presents no problem when communicating with VAX/VMS.  The VAX 
can be set to do the wrapping for the terminal.   Also,  VT52 printer escape 
sequences are not emulated.   That might be a nice feature (but I can't  use 
it so I didn't bother).

     VT52 is written in Z80 code.   This was necessary to support the mode 2 
interrupts  used for high speed.   Block move instructions are also used  in 
the  video  code.   To assemble,  I used Z80MR,  a public domain  Z80  macro 
assembler  (available  for Micro-Cornucopia,  P.O.  Box  223,  Bend,  Oregon 
97709).   To re-assemble,  type Z80MR VT52.AAA (similar to ASM).   The other 
source files are INCLUDED by VT52.AZM.

     If anyone has problems, suggestions, questions, etc. send them to:

     Ray Rizzuto
     43 Sandra Road
     Voorhees, N.J. 08043
     Compuserve ID 72765,700