electronic form such as IGES format. As a consequence, CAx software vendors who want to market their products to DoD subcontractors and their partners needed to support the import (reading) and export (writing) of IGES format files. An ANSI standard since 1980, IGES has been used in the automotive, aerospace, and shipbuilding industries. It has been used for weapons systems from Trident missile guidance systems to entire aircraft carriers. These part models may have to be used years after the vendor of the original design system has gone out of business. IGES files provide a way to access this data decades from now. Today, plugin viewers for Web browsers allow IGES files created 20 years ago to be viewed from anywhere in the world. After the initial release of STEP (ISO 10303) in 1994, interest in further development of IGES declined, and Version 5.3 (1996) was the last published standard. File format An IGES file is composed of 80-character ASCII records, a record length derived from the punched card era. Text strings are represented in "Hollerith" format, the number of characters in the string, followed by the letter "H", followed by the text string, e.g., "4HSLOT" (this is the text string format used in early versions of the Fortran language). Early IGES translators had problems with IBM mainframe computers because the mainframes used EBCDIC encoding for text, and some EBCDIC-ASCII translators would either substitute the wrong character, or improperly set the parity bit, causing a misread. Here is a very small IGES file from 1987, containing only two POINT (Type 116), two CIRCULAR ARC (Type 100), and two LINE (Type 110) entities. It represents a slot, with the points at the centers of the two half-circles that form the ends of the slot, and the two lines that form the sides. S 1 1H,,1H;,4HSLOT,37H$1$DUA2:[IGESLIB.BDRAFT.B2I]SLOT.IGS;, G 1 17HBravo3 BravoDRAFT,31HBravo3->IGES V3.002 (02-Oct-87),32,38,6,38,15, G 2 4HSLOT,1.,1,4HINCH,8,0.08,13H871006.192927,1.E-06,6., G 3 31HD. A. Harrod, Tel. 313/995-6333,24HAPPLICON - Ann Arbor, MI,4,0; G 4 116 1 0 1 0 0 0 0 1D 1 116 1 5 1 0 0D 2 116 2 0 1 0 0 0 0 1D 3 116 1 5 1 0 0D 4 100 3 0 1 0 0 0 0 1D 5 100 1 2 1 0 0D 6 100 4 0 1 0 0 0 0 1D 7 100 1 2 1 0 0D 8 110 5 0 1 0 0