.BG
.FN tty5620
.FN tty630
.FN mux
.TL
Graphics Device DMD Terminals
.CS
tty5620(ask=FALSE, load=TRUE, file="")
tty630 (ask=FALSE, load=TRUE, file="")

mux(ask=FALSE, file="")
.AG ask
logical, should device driver ask before clearing
graphic display for a new figure?
.AG load
logical, should the appropriate terminal program be downloaded
into the terminal?
.AG file
character file name where output should be directed.
By default, output is sent to the terminal for plotting.
.SH COMMENTS
The functions `tty5620', `tty630' and
.Co mux
are the device functions for the Teletype 5620 Dot Mapped
Display terminal and the AT&T 630 Multi-Tasking
Graphics Terminal.
Both terminals contain microprocessors that must
be down-loaded with the S terminal driver program
before graphics can be performed.
Function `mux' can be
used only when you have already downloaded the terminal program.
.PP
The 5620 terminal must be running a windowing program, variously
known as
.I layers ,
.I mux ,
or
.I mpx .
When the device function is executed, it requests that you
designate a layer with button 3.
(When using
.I layers ,
the cursor icon will turn into a bullet and you
should point to any other layer already on the screen to designate
it as the graphics layer.
When using
.I mux ,
the cursor will turn into a small square and
you should sweep out a rectangle.)
The designated layer is where all graphical
output will be directed.
If you wish to draw in another layer, you can use `mux()' to
initiate selection of a new layer.
.PP
On the 630 terminal, you can download the S graphics terminal program
into the terminal even if you are not running 
.I layers .
When the device function is activated, you should sweep out
a recatangle for graphics using button 3.
When you exit from S, the standard layer is restored, but because
the terminal program is cached, it is very quick to load
whenever you execute `tty630' again.
.PP
If `ask' is `TRUE',
whenever a new plot is about to be produced the message "GO?" appears.
This allows further viewing,
before the graphics screen is erased.  When ready
to proceed, simply hit carriage return.
.PP
For graphic input, position the mouse and push button 1.
Hitting two buttons together terminates graphic input.
.PP
At present, the terminals cannot change character size or line type.
Characters can be horizontal or rotated 90 degrees.
The terminal can fill polygons,
for example in histograms, bargraphs, and pie charts
with various patterns.  This is activated
by the color parameter (`col=').
Colors are 1=solid, 2=grey, ....
Color 0 fills with the background color.
.PP
A device must be specified before any graphics functions can be used.
.SA
Related dynamic graphics functions include: `blitid', `spin', `scatmat'.
.KW device
.WR
