The MGR Window System HOWTO

The MGR Window System HOWTO
Vincent Broman
Draft, 30 May 1996
____________________________________________________________

Table of Contents

1. This HOWTO

1.1 Archiving
1.2 Authentication
1.3 Credit for the HOWTO

2. What is the MGR window system?

2.1 Function
2.2 Requirements
2.3 How do MGR, X11, and 8.5 compare?

3. Installing MGR

4. Running MGR

4.1 Applications not aware of MGR
4.2 MGR Applications (clients) distributed with the server
4.3 MGR-aware clients distributed separately, see "SUPPORT" file

5. Programming for MGR

6. More documentation

7. Credit for MGR

______________________________________________________________________

1. This HOWTO

Copyright Vincent Broman 1995.
Permission granted to make and distribute copies of this HOWTO
under the conditions of the GNU General Public License.

1.1. Archiving

This HOWTO is archived in ftp://archimedes.nosc.mil/pub/Mgr/MGR-
HOWTO.sgml, and also distributed from
ftp://sunsite.unc.edu/pub/Linux/docs/HOWTO/MGR-HOWTO. In nearby
directories the same document may appear in alternate formats like
MGR-HOWTO.txt.

1.2. Authentication

Copies of the MGR distribution due to Broman should be accompanied by
PGP signature files, signed by "Vincent Broman <[email protected]>".

1.3. Credit for the HOWTO

While Vincent Broman first put together this HOWTO, much of the
information and text was obtained from FAQs, READMEs, etc. written by
Stephen Uhler, Michael Haardt, and other public-spirited net-persons.
Email corrections and suggested changes to [email protected].
Uhler was the main architect of MGR -- see the Credit section below.

2. What is the MGR window system?

2.1. Function

MGR (ManaGeR) is a graphical window system. The MGR server provides a
builtin window manager and windowed graphics terminal emulation on
color and monochrome bitmap displays. MGR is controlled by mousing
pop-up menus, by keyboard interaction, and by escape sequences written
on pseudo-terminals by client software.

MGR provides each client window with: termcap-style terminal control
functions, graphics primitives such as line and circle drawing;
facilities for manipulating bitmaps, fonts, icons, and pop-up menus;
commands to reshape and position windows; and a message passing
facility enabling client programs to rendezvous and exchange messages.
Client programs may ask to be informed when a change in the window
system occurs, such as a reshaped window, a pushed mouse button, or a
message sent from another client program. These changes are called
events. MGR notifies a client program of an event by sending it an
ASCII character string in a format specified by the client program.
Existing applications can be integrated into the windowing environment
without modification by having MGR imitate keystrokes in response to
user defined menu selections or other events.

2.2. Requirements

MGR currently runs on Linux, FreeBSD, Sun 3/4 workstations with SunOS,
and Coherent. Various older versions of MGR run on the Macintosh,
Atari ST MiNT, Xenix, 386-Minix, DEC 3100, and the 3b1 Unix-pc. Many
small, industrial, real-time systems under OS9 or Lynx in Europe use
(another variant of) Mgr for their user interface. The programming
interface is implemented in C and in ELisp, although supporting
clients written in other languages is quite easy.

Running MGR requires much less in resources than X, or even gcc. It
does not have the user-base, software repertory, or high-level
libraries of X or MS-Windows, say, but it is quite elegant and
approachable.

It has been said that MGR is to X as Unix was to Multics.

2.3. How do MGR, X11, and 8.5 compare?

MGR consists of a server with builtin window manager and terminal
emulator, and clients which run in this terminal emulator and use it
to communicate with the server. No resource multiplexing is done.

X11 consists of a server and clients, which usually connect to the
server using a socket. All user visible things like terminal
emulators, window managers etc are done using clients. No resource
multiplexing is done.

8.5, the Plan 9 window system, is a resource multiplexer, as each
process running in a window can access /dev/bitblt, /dev/mouse and
/dev/kbd in its own namespace. These are multiplexed to the
/dev/bitblit, /dev/mouse and /dev/kbd in the namespace of 8.5. This
approach allows one to run 8.5 in an 8.5 window, a very clean design.
8.5 further has an integrated window manager and terminal emulator.

3. Installing MGR

The latest source distribution can be FTPed from the directory
ftp://archimedes.nosc.mil/pub/Mgr/69 or Mosaiced from
http://archimedes.nosc.mil/Mgr/69. The same should be found at
ftp://sunsite.unc.edu/pub/Linux/apps/MGR and its mirrors. Older
versions of this distribution from Haardt can be found on
tsx-11.mit.edu and perhaps elsewhere. Pre-Linux versions of MGR from
Uhler and others have been found at ftp://bellcore.com/pub/mgr, but I
think they are gone now. I have saved a copy of everything about MGR
seen on the Internet, but I am not aware of anything weighty that is
missing from this Linux/Sun distribution. MGR has been through a lot
of versions and releases, but the current *Linux* version number is
0.69. This version number could jump to 1.0 when stable 256-color VGA
code for Linux appears (for more than one video card type). RCS
version numbers have increased from Bellcore's 4.3 up to our 4.13 now.

Required tools to build this distribution of MGR are m4 (GNU, or
perhaps another supporting the -D option), make (GNU, or perhaps
another supporting include) and *roff for the docs. Also sh, awk, and
POSIX install. Binary distributions are not assembled often so you
need an ANSI C compiler environment, e.g. gcc.

A Linux installation requires Linux 0.99.10 or better (1.2.13 is what
I actually test on now), an HGC, EGA, VGA, or SVGA graphics card, and
a mouse. Mouses supported are: serial Microsoft mouse, serial
MouseSystems 3 and 5 byte mouse, serial MMSeries mouse, serial
Logitech mouse, PS/2 mouse, or a bus mouse. With Buckey (Meta) hot
keys enabled, even a mouseless system could do a certain amount of
useful work under MGR. The VGA 640x480 monochrome graphics mode is
supported out of the box, as is 640x350 and 640x200. To run 800x600,
or other modes that your BIOS can initialize and which do not require
bank-switching, you need to run a small program (supplied as
src/vgamisc/regs.exe) under DOS or an emulator to read the VGA
registers and write a header file which you place in the directory
src/libbitblit/linux, so that it can be #include'd by the vga.c file
there. Samples of these files are supplied, but please create your
own. Some VGA cards can use 128k windows, and these might run higher
monochrome resolutions.

The Linux-colorport code also runs in the standard 320x200x256 color
VGA mode without difficulty, because no bank switching is required.
If you think of how few 64000 pixels is, you would realize this color
mode is quite limited. Non-fast, but simple, bank-switching code has
been added in version 0.65, and it works with a Tseng ET4000 card in
640x480x256 and 800x600x256 modes. The S3 code does not work in super
VGA resolutions, yet. Supporting new super VGA cards requires writing
one function to switch banks and then making sure that the desired
screen mode can be initialized from a register dump, possibly with
hand-tweaking. The Linux color servers generally mangle the screen
fonts, necessitating use of restorefont as in runx. If someone were
to extract the VGA initialization code out of X, this might make MGR
work on a lot more color systems.

Suns with SunOS 4.1.2+ and bwtwo, cgthree, or cgsix frame buffers are
supported. Their speed handling color is good. Coherent
installations should refer to the Versions/README.Coh file in the
source distribution. Porting the latest-and-greatest MGR to another
POSIX-like system which provides select() and pty's and direct access
to a bitmapped frame-buffer ought to be straightforward, just
implementing the libbitblit library based on the sunmono or colorport
code, say.

If you want to install everything, you need 7 MB disk space for
binaries, fonts, manual pages etc. The sources are about 4.5 MB, plus
object files during compilation.
Normally, /usr/mgr should be either the directory or a link to the
directory where you install MGR stuff for runtime use. Typing

cd /usr/mgr; tar xvfz whereveryouputit/mgrusr-0.69.tgz

and optionally

cd /usr/mgr; tar xvfz wherever/morefonts-0.69.tgz

will unpack these. The source can be put anywhere, e.g. typing

cd /usr/src/local/mgr; tar xvfz wherever/mgrsrc-0.69.tgz

to unpack the sources from archimedes.nosc.mil.

The source tree can be compiled from one top-level Makefile which
invokes lower-level Makefiles, all of which "include" a "Configfile"
at the top level. The Configfile is created by an interactive sh
script named Configure, which asks you questions, then runs m4 on a
Configfile.m4. So you type something like this:

chdir /usr/src/local/mgr
sh ./Configure
make first
make depend
make install
make clean

It might be wise, before running make, to eyeball the Configfile
generated by the Configure script, checking that it looks reasonable.
(At least one m4 poops out (Sun /usr/bin/m4), creating a very short
Configfile. If this happens, try hand editing a copy of
Configfile.sun or Configfile.lx) One can also make all in any
directory with a Makefile as soon as the libraries have been compiled
and installed. The server, libraries, and some clients have been
linted, but several clients are K&R C code that generates many
compiler warnings.

Several flags in MGRFLAGS can be added/omitted in the Configfile to
change some optional features in the server, viz:

-DWHO
muck utmp file so "who" works

-DVI
code for clicking the mouse in vi moving the cursor

-DDEBUG
enable debugging output selectable with -d options.
-DFASTMOUSE
XOR the mouse track

-DBUCKEY
for hot-key server commands without mousing

-DPRIORITY
for priority window scheduling instead of round-robin; the
active window gets higher priority

-DCUT
for cut/paste between windows and a global snarf buffer

-DMGR_ALIGN
forces window alignment for fast scrolling (monochrome)

-DKILL
kills windows upon tty i/o errors

-DSHRINK
use only some of the screen ($MGRSIZE in environment)

-DNOSTACK
don't permit event stacking

-DBELL
audibly ring the bell

-DKBD
read mgr input from the sun kbd, instead of stdin. This permits
redirection of console msgs to a window.

-DFRACCHAR
fractional character movement for proportional fonts

-DXMENU
extended menu stuff (experimental)

-DMOVIE
movie making extension which logs all operations to a file for
later replay -- not quite working under Linux

-DEMUMIDMSBUT
Emulate a missing middle mouse button by chording

Not all combinations of these options have been tested on all systems.

The BITBLITFLAGS macro should contain -DBANKED if you're trying out
the super VGA color.

C code for the static variables in the server containing icons and
fonts is generated by a translator from icon and font files.

Not all the clients are compiled and installed by the Makefiles.
Clients found under src/clients having capitalized names or not
compiled by the supplied Makefiles may have problems compiling and/or
running, but they may be interesting to hack on. Most of the screen
drivers found under the libbitblit directory are of mainly
archeological interest. Grave robbing can be profitable.

At some point check that your /etc/termcap and/or terminfo file
contain entries for MGR terminals such as found in the misc directory.
If all your software checks $TERMCAP in the environment, this is not
needed, as long as you run eval `set_termcap` in each window.

MGR works better if run setuid root, because it wants to chown ptys
and write in the utmp file. This helps the ify iconifier client work
better and the event passing mechanism be more secure. On Linux, root
permissions are required in order to do in/out on the screen device.
Otherwise, you decide whether to trust it.

In versions around 0.62 there are troubles on the Sun with using the
csh as the default shell. Programs seem to run in a different process
group than the foreground process group of the window's pty, in
contradiction to man pages and posix specs. There is no trouble with
bash, sh, or rc. Ideas why?

4. Running MGR

The only file required in an MGR installation is the server itself.
That would give you terminal emulator windows with shells running in
them and cutting and pasting with the mouse, but no nice clocks, extra
fonts, fancy graphics, etc. Depending on options, a monochrome server
needs about 200K of RAM plus dynamic space for windows, bitmaps, etc.

If /usr/mgr/bin is in your PATH, then just type "mgr" to start up.
After enjoying the animated startup screen, press any key. When the
hatched background and mouse pointer appear, hold down the left mouse
button, highlight the "new window" menu item, and release the button.
Then drag the mouse from corner to corner where you want a window to
appear. The window will have your default shell running in it. Hold
down the left mouse button over an existing window to see another menu
for doing things to that window. Left-clicking on an obscured window
raises it to the top. The menu you saw that pops-up over the empty
background includes the quit command. For people with a two button
mouse: press both buttons together to emulate the missing middle
button used by some clients.

The quit submenu includes the "really quit" option, a suspend option
which should only be used if you run a job-control shell, and a screen
saver and locker option, which waits for you to type your login
password when you come back to your machine.

When trying to run MGR, if you get:

can't find the screen
make sure you have a /dev entry for your display device, e.g. on
a Sun /dev/bwtwo0. If not, as root cd to /dev, and type
"MAKEDEV bwtwo0". Otherwise, you might need the -S/dev/bwtwo0
or (on Linux) the -S640x480 command line option when starting
mgr. On Linux, you might also make sure that /usr/mgr/bin/mgr
was installed setuid root.

can't find the mouse
make sure /dev/mouse exists, usually as a symbolic link to the
real device name for your mouse. If you haven't permission to
write in /dev, then something like a -m/dev/cua0 option can be
given when starting mgr. Also, make sure you've supplied the
right mouse protocol choice when you configured mgr. The mouse
may speak Microsoft, even if that is not the brand name.

can't get a pty
make sure all of /dev/[tp]ty[pq]? are owned by root, mode 666,
and all programs referenced with the "shell" option in your
.mgrc startup file (if any) exist and are executable.

none but the default font
make sure MGR is looking in the right place for its fonts.
Check the Configfile in the source or see whether a
-f/usr/mgr/font option to mgr fixes the problem.

completely hung (not even the mouse track moves)
login to your machine from another terminal (or rlogin) and kill
the mgr process. A buckey-Q key can quit MGR if the keyboard
still works.

4.1. Applications not aware of MGR

Any tty-oriented application can be run in an MGR window without
further ado. Screen-oriented applications using termcap or curses can
get the correct number of lines and columns in the window by your
using shape(1) to reshape the window or using set_termcap(1) to obtain
the correct termcap entry.

4.2. MGR Applications (clients) distributed with the server

bdftomgr
converts some BDF fonts to MGR fonts

browse
an icon browser

bury
bury this window

c_menu
vi menus from C compiler errors

clock
digital display of time of day

clock2
analog display of time of day

close
close this window, iconify

color
set the foreground and background color for text in this window

colormap
read or write in the color lookup table

cursor
change appearance of the character cursor

cut
cut text from this window into the cut buffer

cycle
display a sequence of icons

dmgr
crude ditroff previewer

fade
fade a home movie script from one scene to another

font
change to a new font in this window

gropbm
a groff to PBM driver using Hershey fonts

hpmgr
hp 2621 terminal emulator

ico
animate an icosahedron or other polyhedron

iconmail
notification of mail arrival

iconmsgs
message arrival notification

ify
iconify and deiconify windows

loadfont
load a font from the file system

maze
a maze game

mclock
micky mouse clock

menu
create or select a pop-up menu

mgr
bellcore window system server and window manager

mgrbd
boulder-dash game

mgrbiff
watch mailbox for mail and notify

mgrload
graph of system load average

mgrlock
lock the console

mgrlogin
graphical login controller

mgrmag
magnify a part of the screen, optionally dump to file

mgrmail
notification of mail arrival

mgrmode
set or clear window modes

mgrmsgs
message arrival notification

mgrplot
Unix "plot" graphics filter

mgrsclock
sandclock

mgrshowfont
browse through mgr fonts

mgrsketch
a sketching/drawing program

mgrview
view mgr bitmap images

mless
start up less/more in separate window, menu added for less

mnew
startup up any program in a separate, independent window

mphoon
display the current phase of the moon

mvi
start up vi in a separate window, with mouse pointing

oclose
(old) close a window

omgrmail
(old) notification of mail arrival

pbmrawtomgr, pgmrawtomgr, ppmrawtomgr
convert raw PBM/PGM/PPM image files to mgr bitmap format

pbmstream
split out a stream of bitmaps

pbmtoprt
printer output from PBM

pgs
ghostscript patch and front end, a PS viewer

pilot
a bitmap browser, or image viewer

resetwin
cleanup window state after client crashes messily

rotate
rotate a bitmap 90 degrees.

screendump
write graphics screen dump to a bitmap file

set_console
redirect console messages to this window

set_termcap
output an appropriate TERM and TERMCAP setting

setname
name a window, for messages and iconifying

shape
reshape this window

square
square this window

squeeze
compress mgr bitmap using run-length encoding

startup
produce a skeleton startup file for current window layout

texmgr
TeX dvi file previewer

text2font, font2text
convert between mgr font format and text dump

unsqueeze
uncompress mgr bitmap using run length encoding

vgafont2mgr, mgrfont2vga
convert between mgr font format and VGA

window_print
print an image of a window

zoom
an icon editor

bounce, grav, grid, hilbert, mgreyes, stringart, walk
graphics demos

4.3. MGR-aware clients distributed separately, see "SUPPORT" file

calctool
on-screen calculator

chess
frontend to /usr/games/chess

gnu emacs
editor with lisp/term/mgr.el mouse & menu support

gnuplot
universal scientific data plotting

metafont
font design and creation

origami
folding editor

pbmplus
portable bitmap format conversions, manipulations

plplot
slick scientific data plotting

The Emacs support in misc/mgr.el and misc/mailcap includes very usable
MIME support, via Rmail and metamail.

A general image viewer could be cobbled together from pilot and the
netPBM filters, but I have not taken the time to do it.

5. Programming for MGR

The MGR programmers manual, the C language applications interface, is
found in the doc directory in troff/nroff form. It covers general
concepts, the function/macro calls controlling the server, a sample
application, with an index and glossary.

Porting client code used with older versions of MGR sometimes requires
the substitution of

#include <mgr/mgr.h>

for

#include <term.h>
#include <dump.h>

and clients using old-style B_XOR, B_CLEAR, et al instead of BIT_XOR,
BIT_CLR, et al can be accommodated by writing

#define OLDMGRBITOPS
#include <mgr/mgr.h>

Compiling client code generally requires compiler options like the
following.

-I/usr/mgr/include -L/usr/mgr/lib -lmgr

One can get some interactive feel for the MGR server functions by
reading and experimenting with the mgr.el terminal driver for GNU
Emacs which implements the MGR interface library in ELisp.

The usual method of inquiring state from the server has the potential
of stumbling on a race condition if the client also expects a large
volume of event notifications. The problem arises if an
(asynchronous) event notification arrives when a (synchronous) inquiry
response was expected. If this arises in practice (unusual) then the
MGR state inquiry functions would have to be integrated with your
event handling loop.

The only major drawing function missing from the MGR protocol, it
seems, is an area fill for areas other than upright rectangles. There
is new code for manipulating the global colormap, as well as
(advisory) allocation and freeing of color indices owned by windows.

If you are thinking of hacking on the server, you can find the mouse
driver in mouse.* and mouse_get.*, the grotty parts of the keyboard
interface in kbd.c, and the interface to the display in the
src/libbitblit/* directories. The main procedure, much
initialization, and the top level input loop are in mgr.c, and the
interpretation of escape sequences is in put_window.c.

6. More documentation

The programmer's manual is essential for concepts.

Nearly all the clients supplied come with a man page which is
installed into /usr/mgr/man/man1 or man6. Other useful man pages are
bitblit.3, font.5, and bitmap.5. There is some ambiguity in the docs
in distinguishing the internal bitmap format found in your frame-
buffer and the external bitmap format found in files, e.g. icons.

The mgr.1 man page covers command line options, commands in the
~/.mgrc startup file, mouse and menu interaction with the server, and
hot-key shortcuts available on systems with such hot-keys.

Many of the fonts in /usr/mgr/font/* are described to some extent in
/usr/mgr/font/*.txt, e.g. /usr/mgr/font/FONTDIR.txt gives X-style font
descriptions for the fonts obtained in .bdf format. Font names end in
WxH, where W and H are the decimal width and height in pixels of each
character box.

7. Credit for MGR

Stephen Uhler, with others working at Bellcore, was the original
designer and implementer of MGR, so Bellcore has copyrighted much of
the code and documentation for MGR under the following conditions.

* Permission is granted to copy or use this program, EXCEPT that it
* may not be sold for profit, the copyright notice must be reproduced
* on copies, and credit should be given to Bellcore where it is due.

One required showing of the copyright notice is the startup title
screen.

Other credits to:

o Stephen Hawley for his wonderful icons.

o Tommy Frandsen for the VGA linux library.

o Tom Heller for his Gasblit library.

o Andrew Haylett for the Mouse driver code.

o Dan McCrackin for his gasblit->linux patches.

o Dave Gymer, [email protected], for the Startrek effect fix.

o Alex Liu for first releasing a working Linux version of MGR.

o Lars Aronsson ([email protected]) for text2font and an
ISO8859-1 8-bit font.

o Harry Pulley ([email protected],
[email protected]) for the Coherent port.

o Vance Petree & Grant Edwards & Udo Munk for their work on Hercules.

o Udo Munk for his work on serial mouse initialization & select.

o Norman Bartek & Hal Snyder at Mark Williams Co. for their help
with some bugs & with Coherent device drivers.

o Extra thanks to Zeyd Ben Halim for lots of helpful patches,
especially the adaptation of selection.

o Bradley Bosch, [email protected], for lots of patches from his 3b1
port, which fix bugs and implement new and desirable features.

o Andrew Morton, [email protected], who first wrote the cut-
word code.

o Kapil Paranjape, [email protected], for the EGA
support.

o Michael Haardt for MOVIE support fixes, bug fixes, separation of
the libbitblit code into output drivers, expansion of the libmgr,
and origami folding of the code.

o Yossi Gil for many fonts.

o Carsten Emde, [email protected], for mphoon.

o Vincent Broman for middle mouse-button emulation, linting, Sun
cgsix support, VGA colormap acess, integration of the sunport code
into Haardt's layering scheme, font gathering, the screen saver,
and continued maintenance.

o Kenneth Almquist, [email protected], for helpful bug reports.

o Tim Pierce, [email protected], for the port to FreeBSD
2.0R with Trident VGA.

All bitmap fonts from any source are strictly public domain in the
USA. The 583 fixed-width fonts supplied with MGR were obtained from
Uhler, the X distribution, Yossi Gil, and elsewhere. The Hershey
vector fonts and the code for rendering them are probably freely
redistributable.