3.5.1 Modes of Operation

With XFD file

If you've built a data dictionary (also known as an Extended File Descriptor or XFD) for your indexed file, alfred can access the data dictionary to obtain specific information about the fields in each record, and can display the records according to their field structure. This makes the file easy to read on your screen and all editing is done at the field level.

To build an XFD file, specify the "-Fx" option when you compile your COBOL program. For more information about XFD files, their creation and use, see section 5.3.

Note that although ACUCOBOL-GT allows Vision files to have as many as 119 alternate keys, memory limitations restrict alfred to XFD files having no more than 114 alternate keys. Attempting to open an XFD file containing more than 114 alternate keys results in a memory access error.

Without XFD file

If you don't have an XFD file, alfred can still access and display the records. However, it has no field-level information about the file and, therefore, data is presented in groups of characters. All user interactions are done at the character level, either in ASCII, hexadecimal, or octal.