DEC Regis Terminals
- T. J. Pearson, 1988.
- Supported devices
- Digital Equipment Corporation VT125, VT240, or
VT241 terminal; other REGIS devices may also work.
- Device type code
- Default file name
TT:PGPLOT.VTPLOT. This usually means the
terminal you are logged in to (logical name
TT), but the plot can be
sent to another terminal by giving the device name, e.g.,
it can be saved in a file by specifying a file name (in this case a disk
name must be included as part of the file name).
- Default view surface dimensions
- Depends on monitor.
- The default view surface is 768 (horizontal) by
460 (vertical) pixels. On most Regis devices, the resolution is
degraded in the vertical direction giving only 230 distinguishable
raster lines. (There are actually 240 raster lines, but 10 are reserved
for a line of text.)
- Color capability
- Color indices 0--3 are supported. By default,
color index 0 is black (the background color). Color indices 1--3
are white, red, and green on color monitors, or white, dark grey, and
light grey on monochrome monitors. The color representation of all
the color indices can be changed, although only a finite number of
different colors can be obtained (see the manual for the terminal).
- Input capability
- The graphics cursor is a blinking
diamond-crosshair. The user positions the cursor using the arrow keys
and PF1--PF4 keys on his keyboard [Note: NOT the keyboard of
the terminal on which he is plotting, if that is different.]
The arrow keys move the cursor in the appropriate direction; the size
of the step for each keystroke is controlled by the PF1--PF4 keys: PF1
= 1 pixel, PF2 = 4 pixels, PF3 = 16 pixels, PF4 = 64 pixels. [The
VT240 terminal has a built-in capability to position the cursor, but
PGPLOT does not use this as it is not available on the VT125.] The
user indicates that the cursor has been positioned by typing any
character other than an arrow or PF1--PF4 key [control characters, eg,
ctrl-C, and other special characters should be avoided, as they
may be intercepted by the operating system].
- File format
- A REGIS plot file is formatted in records of 80
characters or less, and has no carriage-control attributes. The
records are grouped into ``buffers,'' each of which begins with a command
to put the terminal into graphics mode and ends with a command
to put it back into text mode. The terminal is in graphics mode only
while a buffer is being transmitted, so a user's program can write to
the terminal at any time (in text mode) without worrying if it might
be in graphics mode.
- Obtaining hardcopy
- A hardcopy of the plot can be obtained
using a printer attached to the VT125/VT240 terminal (see the
instruction manual for the terminal). A plot stored in disk file
can be displayed by issuing a
TYPE command (e.g.,
on a VT125 or VT240.