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Startup file

When LEXT is started it looks for a file called LEXT.STARTUP. This file should contain the dimensions of the stacks and slots and the optionally the command INIT, which actually makes the memory available for the list data block. INIT is only required if the startup procedure contains further LEXT commands, say, to automatically read in the list data files. If LEXT.STARTUP is not present then defaults are used where applicable and the remaining values are prompted for.

The dimensions of the image slots and are SET via the following internal variables:

• Nx defines the number of image pixels in the X-direction.
• Ny defines the number of image pixels in the Y-direction.

Further LEXT or DCL commands can be issued from the startup file allowing the user to customise the session, and read in commonly required data. In the case of lists use, the command INIT must first be used to tell LEXT to create the necessary internal data storage.