Its main purpose is to control ATA(PI) devices connected to an IDE64 cartridge and present them like normal Commodore drives.
The native file system is non-CBM style at the low level to allow partitions greater than 16 MiB.
Additional filesystems like ISO 9660 or FAT are abstracted internally and mostly use the same routines for handling, thereby little difference is noticeable to user programs, except if some features are not fully implemented.
Unlike intelligent external devices which have a separate processor (like 1541 with CBM DOS), IDEDOS runs on the host computer, thereby all disk routines block until finished.
Interrupts are generally allowed while IDEDOS is running (they are disabled on rare time-critical operations), however the system was written to be non-reentrant, just like the original KERNAL.
It was created by Josef Souček (main code) and Tomáš Přibyl (File manager, Final cartridge monitor adaptation).
Due to limitations of the design the development of a completely rewritten version (0.90) was started by Kajtár Zsolt, which was not ready for general use before 2005.
Supported devices: Includes clock with calendar, ability to set drive numbers, screen colours, auto boot, floppy fast loader, basic clock (TI$), power management, write retry, read-ahead and write cache drive settings, CD-ROM slow down option.
The BASIC extension includes disk handling commands (limited to IDEDOS devices), and adds some new error messages.
The goal was to have freezer style (all registers including I/O editable) and fast machine code monitor which supports illegal 6502 and SuperCPU emulation mode opcodes.