Did you know that just a couple decades ago, computers from different brands would not have been able to recognize the same files? The data for each different kind of computer was stored in many different formats. Standardized formats began to emerge as personal computer usage became more prevalent and people collaborating on projects needed to access their work from multiple different computers. This month, we explain the difference between some common formats for the data on CDs.
ISO9660 – Level 1: The original file CD data format uses a DOS file format of 8 characters followed by a dot and a 3-character extension. The goal of this file system was to enable multiple computer operating systems, including Windows, classic Mac OS, and other Unix-like systems to work with the same files.
ISO9660 – Level 2: This newer extension of the ISO9660 format allows filenames with up to 31 characters. It’s recognized by all major operating systems including Windows, Mac, and Unix.
ISO9660 – Level 3: This update to the file system format allows computers to create non-contiguous files, which means that the data for the document is not stored all in one place but rather in fragments. Making this change resulted in more efficient data storage. Before, new documents were limited in size to the largest available space in memory. With this change, the limit was increased so new documents could be as large as the total amount of available space on the drive.
JOLIET: Based on ISO9660, this file system format was designed to provide file naming with additional options, such as more characters, including spaces, and names up to 256 characters long. You should still include only one dot immediately before the 3-character extension. Helpful for PCs running in languages that use different alphabets, this update runs side-by-side with ISO9660 and Mac formats on many CDs.
HYBRID (PC/Mac): Hybrid discs use MAC HFS format and PC ISO9660 and Joliet on the same CD, allowing the one CD to be played in either a PC or a Mac. The combination of file system formats is what does the trick.
