There are several graphics "languages" available to you via "driver" programs that allow GCG programs access those languages. Each language is capable of "driving" a range of plotting equipment, or "devices". The preferred route on AGRENET is to use a driver called UNIGKS. GKSTERM is a driver-selection program that allows you to select from a list of "devices", that the UNIGKS driver knows about. You select the device at the following prompt. For VT340 for example:
Choose one option by name or number (* P7800 *) : VT340
After the device is chosen, you must tell it where to send ("port") the graphics. By default the driver-selection program uses the word "TERMINAL" to send it to the device on your desktop. This is usually your VDU or a plotter connected to your VDU. By giving a filename instead of "TERMINAL" the file then becomes the "port", ie: graphics instructions are written to that file. You can later plot the file on another device.
When you first start GCG on AGRENET, the GKS driver is selected automatically, directing graphics output to a UNIPICT file called WISC.UPI. Use the program PLOT to display the graphics in WISC.UPI on a range of graphic devices, or edit the graphics using UNIEDIT.
A UNIPICT file can be converted into a Freelance CGM file, using the program PITOFL. The file can then be transferred to a PC and edited using the Freelance, Drawperfect or Wordperfect packages.