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**** The Hebrew University of Jerusalem ****
**** Computation Center ****
News Bulletin #17
25-March-1991
Today's topics:
- VI and Emacs editors available on the VAX.
- XTERM terminal emulator is available.
- TALK command and its problems.
- Email routing changes.
- graphics on the VAX: Output devices and software packages.
o VI and Emacs available: The Unix editors VI and Emacs are available
on the VAX. Both editors are public domain ones (see note bellow)
and can be freely copied (you can find them packed in
PUBLIC$:[EDITORS]). VI is based on the VMS standard TPU utility
while Emacs is written in C. In order to use them you have to issue
the PROVIDE command, once for VI and once for EMACS. VI is also
described under HELP VI topic.
Note: These are public domain programs and you use them on your own
risk!
o XTERM available: The standard terminal emulator used by the X11
standard is available. This terminal emulator can be used only on
workstations and X11 terminals. It can be used instead of the
standard terminal emulator for those who feel better with it. The
main advantage of it is that it supports TEK-4010 graphics (although
we try to convert most graphical packages to use X11 directly). See
HELP XTERM for more details.
NOTE: This is a public domain program and you use it on your own
risk. Furthermore, it might stop working some day due to changes in
VMS.
o TALK command: TALK is a protocol used for communicating
interactively with users on other systems supporting the TcpIp
protocol (InterNet machines). There are two versions of Talk. One
is called "old talk" and it is the default on most Unix systems
(here it is activated with TALK/OLD). The other one is the "new
talk" operated on most Unix systems as Ntalk (if exists at all) and
it is the default here. As you guess almost all machines support
the old version. However, this version has a serious bug: it can't
be used between machines whose byte order is different (VAX and
DECstations from one side and Sun, Convex and others on the other
side). In this case you usually get no error message or an error
message "address family is not supported". The New talk is designed
to operate over all machines types. However, not all machines
support it. If they do not support it you usually get no error
message. Hence, if you want to talk to someone from here, first try
TALK ; if nothing usefull comes out of it (and no message like
"ringing your party") try TALK/OLD. If this neither helps and you
can access the remote machine by other means (like TELNET or FINGER)
then you are probably out of luck and you can't use Talk to that
machine.
o Email routing changes: It is better later than never: A few
changes have been made recently in Email routing after the new 64kb
IP link to U.S.A. was established. All InterNet mail is sent
directly over the IP link to its final destination. BITnet mail to
almost any place except Europe is also routed over this link to
RICEVM1. The BITnet traffic to Europe conctinues to flow over the
old link to FRMOP22 which is now less loaded.
o Graphics on the VAX: This is a partial summary of the demonstration
of windowing (not included here), graphics and output devices.
Graphics is supported on the VAX using a few packages, ranging from
the most simple ones to the quite complex ones. The user's
interface to these packages is the the graphical input/output
device. The commonly used and available here are:
Tektronix-4010 - This is the simplest device and almost all the
graphical terminals emulate this protocol. Allmost all software
packages support it and it can be thought as the lowest common
interface available. It supports simple graphics, black & white
only, and most of the terminals support also cross-hair input (i.e.
a crosshair is drawn which can be moved to the desired point and its
coordinates are fed to the program).
Tektronix-4200 series - These are enhancements of the simple
Tektronix-4010 terminal. This device supports colors, and there is
one such terminal (4207 model) available for public use (at the VMS
group at the Taylor building).
The main drawback of the above two terminals is that they are slow
(equiped with slow communication interface). The advantage is that
they are common, cheap (the 4010 emulators, not the 42xx ones...)
and at the size of a "normal" terminal.
Tektronix emulators: There are a few types of terminals which are
not Tektronix but emulate it. Among them there are also terminal
emulators for the PC, like Kermit and NCSA/telnet. both check what
screen type you have (EGA, VGA etc.) and displays the graphics
accordingly. The advantage of the NCSA/telnet is its speed as it
uses ethernet for its communication medium.
X11 terminals (sometimes called DECwindows also) - These are the
"windowing" terminals which support also the X11 standard which
includes standard graphical routines and is beginning to be quite
common. The main advantages of this terminal type are: it is
usually connected to an ethernet so the drawings are quite fast; it
supports windowing; the graphical interface is standard and it
doesn't matter what is the machine on the other side; it is
available in a wide range of screen types. The main disadvantages
are that it is more expensive than the simple terminal and it needs
some supporting host to load itself.
WorkStations: In this context these are enhancements of the X11
terminals thus will not be discussed here.
Now that we know about the output devices supported at our
installation we can see what packages we have and what they can do
for us:
MONGO - This is one of the simplest programs we have. It is mainly
an interactive program although you can write programs that call its
routines. This package is most suitable for displaying simple plots
of data raws you have. It'll plot the dots connected by lines (of
varying types) and will do it easily. It supports output on all the
devices listed above.
GNUPLOT - This is also a basic interactive package which supports
also functions plotting. One important feature of it is that it can
generate graphs in Latex format which can be included into an
article written using Tex/LaTex. This program is available also on
the Unix system of the computation center.
PGPLOT - This is a public domain package which includes routines for
2D plotting and simple 3D plotings. It supports also a cross-hair
input from the user. It also supports colors on displays that
support it. This package is recommended if you need a comprehensive
2D programming and yet do not want to use more complex (and thus
harder to program) packages.
EXPONENT - This is a package which comlements the IMSL mathematical
routines but can be used as a stand-alone graphical package. Simple
yet powerfull, it supports both 2D and 3D graphics while still being
not over-complex.
Note: This package is not available yet for public use but will be
very soon.
You can get support for all the above packages from: Marian Dodu
(MARIAN@VMS) and Michael Engel (MICKY@CC).
__Yehavi:
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