Date   : Mon, 13 Jun 1988 13:40:36 EDT
From   : <SAGE@LL.ARPA>
Subject: MEX-Plus Terminal Emulation Information

There have been a number of requests for information about MEX-Plus and its
terminal emulation capability.  The following is offered to answer what
questions I can at this point.  I do not use the emulation on my CP/M
machines, so I cannot offer comments from first-hand experience.  Even on my
Compaq 386, I use the emulation only in its simplest form (i.e., not talking
to programs that expect to see a real VT100 terminal).
 
I finally located a copy of the MEX manual with the pages on the emulation
package.  It is a combined manual (CP/M and IBM-PC), so I cannot be sure at
this point that all of the features are supported in the CP/M version.
 
Here is what the manual says about the DEC VT52/100 emulator (taken from
manual -- I don't even understand what all these things mean).
 
 
The VT52/100 emulator supports the following features of the DEC VT100
terminal:
 
    VT52 support       Cursor Up          Cursor Down        Cursor Left
    Cursor Right       Cursor Position    Cursor Read        Newline
    Char Insert        Char Delete        Line Insert        Line Delete
    Reverse Screen     Scrolling Region   "Origin" Mode      Auto-Wrap
    Cursor Pos.        Index              Reverse Index      Next-Line
    Horiz. Tabs        Erase Line         Device Status      Dev. Attributes
    Identify Term.     Report Cursor Pos.
 
        Save/restore cursor and attributes
        Select graphics dendition (bold/blink/reverse vid/underline)
        Clear screen: full, start-screen-to-cursor, cursor-to-end
        Clear line: full, start-line-to-cursor, cursor-to-end
        Alternate character sets (excluding VT100 optional ROMs)
 
Not supported are the answerback message, smooth-scroll, 132-column mode,
printer functions, terminal self-tests, and keyboard LED's (although all the
escape sequences associated with these functions are accepted).
 
Version 1 of the VT100 emulator does not support any interactive setup; this
will likely be added in a future release.  Also, the numeric keypad keys
function only in "numeric" mode; "alternate" mode is not supported.
 
 
The manual also lists the escape sequences transmitted by some of the
special keys on the IBM PC keyboard.  I have not reproduced that information
here.
 
Unfortunately, because the manual is geared toward IBM PCs, it does not list
the functions that must be supported by the host terminal.  From some of the
functions listed, it would appear that beyond the ordinary ones, there
must be support for insert and delete line and probably insert and delete
character.
 
If anyone is seriously interested in acquiring MEX-Plus with the terminal
emulation packages, I will do some experiments or inquire of the author (Ron
Fowler, who used to read this newsletter but appears no longer to be
active).
 
                Jay Sage