Mg 2a README  May 15, 1988

Mg (mg) is a Public Domain EMACS style editor.  It is "broadly"
compatible with GNU Emacs, the latest creation of Richard M.
Stallman, Chief GNUisance and inventor of Emacs.  GNU Emacs (and other
portions of GNU as they are released) are essentially free, (there are
handling charges for obtaining it) and so is Mg.  You may never have
to learn another editor.  (But probably will, at least long enough to
port Mg...)  Mg was formerly named MicroGnuEmacs, the name change was
done at the request of Richard Stallman. 

Mg is not associated with the GNU project, and most of it does not
have the copyright restrictions present in GNU Emacs.  (However, some
of the system dependent modules and the regular expression module do
have copyright notices, specificly the VMS/primos termcap routines and
the amiga specific routines.  Look at the source code for exact
copyright restrictions.)  The Mg authors individually may or may not
agree with the opinions expressed by Richard Stallman in "The GNU
Manifesto".

To avoid GNU copyright restrictions, replace the re_search.c, regex.h
and regex.c files with empty files.

Documentation of Mg is in the TeX file mg.tex.  This should be
formatted with the TeX text formatter and printed.  A start twords a mg
programmers guied in in mgprog.doc, and some of the changes from 1b
are mentioned briefly in mg2a.change.

This program is intended to be a small, fast, and portable editor for
people who can't (or don't want to) run real Emacs thing for one
reason or another.  It is compatible with GNU because there shouldn't
be any reason to learn more than one Emacs flavor.  We have excised
most MicroEMACS features that were incompatible with the big brother,
and added missing features that seemed essential.

There are at least two other major versions of MicroEMACS in
circulation.  One comes from Daniel Lawrence, (based on an old version
from Dave Conroy) and is several versions have been posted to usenet.
It uses a 3.x version numbering scheme, and the latest I know about is
3.9i.  It has some features not found in Mg, missing others, is
bigger, and is incompatible with GNU Emacs.  It might be a better
choice for you if you *must* have something not present here and can't
run GNU.

Another variety uses a different numbering scheme, and is up to v30.
This also comes from mod.sources, and is the latest version from the
original MicroEMACS author Dave Conroy.  Mg is derived from this
version, and for the most part has replaced it.

Mg is continuing to diverge from other MicroEmacs varients.
Significant modifacations would me nessisary to adapt code from either
the 3.x strains or v30.  Command functions and key mapping, for
instance, are completely different.

This is the third distribution release of Mg.  (It went through four
beta releases to iron out the changes made by the various authors.)
Prior releases were known as MicroGnuEmacs 1a and MicroGnuEmacs 1b.
Beyond the work of Dave Conroy, author of the original public domain
v30, the current version contains the work of:

	blarson@ecla.usc.edu		Bob Larson
	mic@emx.utexas.edu		Mic Kaczmarczik
	mwm@violet.berkeley.edu		Mike Meyer
	sandra@cs.utah.edu		Sandra Loosemore
	mp1u+@andrew.cmu.edu		Michael Portuesi
	RCKG01M@CALSTATE.BITNET		Stephen Walton
	hakanson@mist.cs.orst.edu	Marion Hakanson

People who have worked on previos versions of Mg:

	rtech!daveb@sun.com		Dave Brower

These systems are known to work in the current version:

	4.2 & 4.3 BSD Unix, SunOs 3.2, Ultrix-32
	System V
	OS9/68k
	VMS
	Amiga
	Primos
	Atari ST

Ms-Dos support is planned, but did not get done in time for this
release.  (Jeff Siegal <jbs@eddie.mit.edu> was the one doing it.)
The Ms-Dos files will probably be distributed seperatly when it
becomes available.

Cpm/68k support was dropped due to compiler bugs.  Eunice support was
dropped because of lack of interest.  Mg 1b does support those
systems.

One change to late to make it into mg.tex is readding bsmap-mode (only
if BSMAP is #defined when compiling).  This is a toggle that controls
input mapping to exchange the ^H (backspace) and DEL characters.  Like
GNU emacs input keymaps, it is not displayed on the mode line and will
cause them to be treated as each other for echoing.  (With bsmap-mode
enabled, DEL will echo ^H in the echo line.)


How to Make a Mg
---------------------------

On UNIX at least, it's easy.  (Note that even on these systems you may
want to change a compile time option.)  If you have BSD UNIX, do:

	ln sys/bsd/Makefile .
	make

For System V, do:

	ln sys/sysv/Makefile .
	make

There are several other directories under sys: osk, vms, amiga, atari,
prime.  You should follow the directions contained therein to make one
of those versions.

For most systems (everyting except the amiga, and atari currently),
the termcap terminal definition is used.  There is a readme file in
the default subdirectory of the sys directory explaining what entries
are used and how.  (Termcap is a way to do display manipulation in a
terminal independent manner.) Besides the normal startup file (usually
.mg) terminal specific initialization files may be used.  (For
example, in .mg.vt100 you may want to (global-set-key "\e[A"
'previous-line) to have the up arrow key work.)

Some changes made to make this version more like Gnu Emacs may break
startup files.	Gnu Emacs 18 has both backward-delete-char and
delete-backward-char that apperently do the same thing.	 This version
has only the latter because that is what is documented in my manual
(version 17) and bound by Gnu Emacs to DEL.

----------------------------------------------------------------------

Known limitaions:

Recursive bindings may cause help and key rebinding code to go into
an infinite loop, aborting with a stack overflow.

Overwrite mode does not work in macros.	 (Characters are inserted
rather than overwriting.)

Dired mode has some problems:  Rename does not update the buffer.
Doing a dired again will update the buffer (whether it needs it or
not) and will lose any marks for deletion.  .. and . are not
recognized as special cases.

On systems with 16 bit integers, the kill buffer cannot exceed 32767
bytes.



New implementation oddities:

insert and define-key are new commands corresponding to the mocklisp
functions in Gnu Emacs.	 (Mg does not have non-command functions.)
(Mg's insert will only insert one string.)

The display wrap code does not work at all like that of GNU emacs.

------------------------------------------------------------------------

If you have a change to make that you think should be incorporated
into the next version of Mg, send it the mg-support mail
list. Addresses are:

	mg-support%ais1@ecla.usc.edu
	{cit-vax,sdcrdcf,trwrb}!oberon!ais1!mg-support

Support for additional systems and terminals should include being
available for beta testing as other changes are made.  (Send a short
note to mg-support.)  Currently, beta test copies of Mg are made
available via Internet ftp, so beta testers need access to the
Internet.  (UUCP sites that are customers of uunet can get it via
them.  Contact uunet!uunet-request for details.) If you can't reach
one of us via a computer network, I suppose you could send a change to
my snail mail address below on 5" os9 format disks or 9 track tape
(ANSI variable label or Prime magsav format), but this effectivly
rules you out as a potential beta tester.  (Don't expect the disk or
tape back unless you inculude a SASE with sufficent postage.)  I will
not be sending out copies on magnetic media, so please don't ask.  If
you somehow got an incomplete or non-standard copy, (i.e. missing one
of the sys directories mentioned here as working) complain to who you
got it from not to me.

	Robert Larson
	309 S. Alexandria Ave.
	Apt. 117
	Los Angeles, CA  90020

Alternatively, and under the same conditions, you can send either a 3"
AmigaDOS format disk or a 9 track tape (Unix tar format) to:

	Mike Meyer
	P.O. Box 4730
	Berkeley, CA 94704
	
