MicroStation 95 Reference Guide
18-1
18 Intergraph Standard File Formats
(Element Structure)
The Intergraph Standard File Formats (ISFF) are the file formats
common to MicroStation and Intergraph’s Interactive Graphics
Design System (IGDS). ISFF is now available to the public. This
enables Intergraph customers and third-party developers to create
custom applications for MicroStation that read and write ISFF
format without a license from Intergaph.
Types of Files
ISFF consists of several types of binary files:
•
Design files
are sequential, variable-length files with variable-
length records for the Design File Header (see page 18-2), file
set-up information, graphic elements, and non-graphic data.
User-defined elements begin with the fourth element.
Design files are typically designated with the extension “.dgn.”
•
Cell libraries
store cell definitions for placement in design
files. A cell library consists of a file header (type 5) element
followed by individual cell descriptions. Each cell is a
complex element that contains a cell library header (type 1)
element and component elements.
Cell descriptions can be nested. Nested cells contain a type 2
header and component elements. If the cell library already
contains the nested cell, its component elements are not
repeated.
Cell libraries are typically designated with the extension “.cel.”
