The interactive graphics programs Caesar, Magic, and Gremlin use two separate terminals: a text terminal from which commands are issued, and a color graphics terminal on which graphical output is displayed. These programs use a displays file to associate their text terminal with its corresponding display device.
The displays file is an ASCII text file with one line for each text terminal/graphics terminal pair. Each line contains 4 items separated by spaces: the name of the port attached to a text terminal, the name of the port attached to the associated graphics terminal, the phosphor type of the graphics terminal's monitor, and the type of graphics terminal.
An applications program may use the phosphor type to select a color map tuned to the monitor's characteristics. Only the std phosphor type is supported at UC Berkeley.
The graphics terminal type specifies the device driver a program should use when communicating with its graphics terminal. Magic supports types UCB512, AED1024, and SUN120. Other programs may recognize different display types. See the manual entry for your specific application for more information.
A sample displays file is:
/dev/ttyi1 /dev/ttyi0 std UCB512
/dev/ttyj0 /dev/ttyj1 std UCB512
/dev/ttyjf /dev/ttyhf std UCB512
/dev/ttyhb /dev/ttyhc std UCB512
/dev/ttyhc /dev/ttyhb std UCB512
In this example, /dev/ttyi1 connects to a text terminal. An associated UCB512 graphics terminal with standard phosphor is connected to /dev/ttyi0.
Magic uses the displays file ~cad/lib/displays. Gremlin looks in /usr/local/displays.