2 Differences between DNFS and HDFS The HDFS has some real advantages over the DNFS. These include. Hierarchical directories The HDFS has a fully hierarchical directory structure, allowing more than the 31 files per disc side of the DNFS. 40/80 track switching If the HDFS is used with an 80 track disc drive, it can automatically detect 40 track discs and read and write to these discs without manual intervention. Advanced tube support The HDFS includes the Acorn Tube Support code, with the extra feature of being able to turn off the Tube from software. Sideways RAM support All of the memory moving, loading and saving operations can access any sideways ROM socket, allowing multiple banks of sideways RAM to be supported. Large files If the HDFS is used with double sided disc drives, it can split files across both sides of the same disc, allowing files up to 400k long. Low memory loading The HDFS can load files into memory which would normally take too much space, automatically disabling itself after the file is loaded. Open files The HDFS supports a total of six files open simultaneously, one more than the DNFS. More commands The HDFS has many more commands than the DNFS, including a fully featured disc, file, and memory editor, disc and memory searching, memory block moving, and a lot more. DNFS compatibility The HDFS is also able to read, write, and format DNFS compatible discs. The majority of programs designed to work under DNFS 1.20 will work under HDFS with no change. Where changes have been required, it has usually been because the program's author(s) have made invalid assumptions about command parsing or memory usage.