.hqx.hqx is the suffix given to Macintosh file which has been converted from a binary format to an ASCII file. Files are converted to this format for the purpose of sending them via electronic mail or other electronic transfer method. Files converted to ASCII can be transported through cyberspace more reliably than if they are kept in their original binary configuration.
.hqx is the extension commonly placed on a Macintosh BinHex file. BinHex (which is short for binary-to-hexadecimal) describes files which have been converted from a binary to BinHex (ASCII) format. A binary formatted file can include anything from a word processor, spreadsheet, graphic or executable file. Once a file has been converted from binary to an ASCII format, it appears as a series of 80-character lines made up of letters of the alphabet, numerals, and punctuation marks. This type of encoded file can be sent in a 7-bit format. A 7-bit format minimizes transfer and downloading requirements and ensures that binary files can be transferred accurately. However, the BinHex file is 35% larger than the corresponding binary file. For this reason, it takes longer to transmit converted BinHex (ASCII) files than binary files.
BinHex 4.0 is the most popular binary to ASCII (text) converter available for the Macintosh computer system. The FTP program Fetch also can get and put files into the BinHex format. For the Macintosh user, this is as easy as selecting the BinHex format from the dialog boxes which pop up when up- and downloading files.
StuffIt Expander, a freeware application for the Macintosh can be used to convert a BinHex file back to its original binary form.
Although BinHex was designed for the Macintosh system, PC and UNIX users should be also be prepared to deal with this encoded format.
Users of the PC and UNIX systems who need to obtain transferred files from a Macintosh system have decompression utilities available to them that can convert the files back to a binary format.
Xbin (36k) is available for MS-DOS users and UNIX users. Although it was designed for UNIX machines, Xbin can be used by MS-DOS users who are willing to troubleshoot a few potential problems. MS-DOS users who encounter problems using Xbin should use the "-n filename" option to specify the target filename, as Xbin only extracts BinHex files; it can not create them. In addition to Xbin, MS-DOS users may utilize PC BinHex 1.3 (45k), which both creates and extracts BinHex files. Windows users may use StuffIt Expander for Windows (349k) to convert BinHex files back to binary.
The popular electronic mail utility, Eudora, was designed for the Macintosh. However, a version of Eudora also exists for PC. PC users who have problems downloading Eudora attachments saved in a BinHex format can download the Eudora PC version from http://www.qualcomm.com and forward mail to themselves when they are faced with having to convert BinHex attachments. This enables PC users to open and read their mail without any problems.