Any program producing graphics (including GCG) needs to know 'what graphics language', 'on what equipment' and 'where', are being used. These requirements translate to the technical terms "driver", "device" and "port". To inform GCG of these you must run a driver-selection program. One of the drivers is selected by default when you start the GCG package.
The UNIGKS driver is provided by the AFRC Computing Division, it is the default and preferred route on AGRENET. GCG has its own set of drivers for a number of devices, including VDU's and plotters. Many GCG sites have a SETPLOT command, providing a list of the devices supported at that site.
$GKSTERM - A selection of UNIGKS-supported devices.
$SIXEL - DEC dot matrix and laser printers, eg: LN03.
$POSTSCRIPT - eg: Apple Laserwriter.
$HPGL - Offers several Hewlett Packard plotters.
$HP7221 - The HP7221 only.
$REGIS - VT340 and other VT devices.
$TEKTRONIX - Several devices are offered (eg: VERSATERM for Mac).
$XWINDOWS - X windows.
$SETPLOT - Site dependent (may not be available).
Any GCG program displaying graphics has a choice of 21 different lettering styles for the text, selected by the command line modifier /Font=number. Each letter is formed by drawing many short lines, aligning the text neatly for each graphical display. To see an example of all the different fonts:
$ Plottest/showfonts
Font 0: (device dependent with UNIGKS driver)
Font 1-6 : Block type.
Font 7-9 : Italic.
Font 10-14 : Gothic.
Font 15-17 : Greek letters.
Font 18: Cyrillic.
Font 19-20: Other symbols.
Most drivers use font 1 as the default. The UNIGKS driver has a default font of zero, displaying lettering as simple text, rather than short lines. The appearance of font zero varies for each device, and it may not be aligned tidily. When saving graphics to a UNIPICT file, any text written as font zero may be edited, other fonts cannot be edited.