See also:

• Computers: Software: Operating Systems: Graphic Subsystems: Desktop Environments: GEM  (11)
• Computers: Software: Operating Systems: Monolithic  (2)
• Computers: Software: Operating Systems: Open Source  (16)
• Computers: Software: Operating Systems: x86: DOS: FreeDOS  (9)

• Dissecting DOS: A Code-Level Look at the DOS Operating System - By Michael Podanoffsky; Addison-Wesley, 1994, ISBN 020162687X, has CD-ROM. Explores DOS structure, function from programmer view, overall architecture, command structure, code-level details of vital actions. [Amazon.com]
• RxDOS - Fast industrial strength DOS compatible RTOS, supports huge disk drives, FAT32 volumes, Windows 95/98 long filenames, coded in Assembly, used mostly in embedded systems and similar uses. [Open Source, GPL]
• RxDOS Downloads - Several Zip format files: readme, bootable MASM files: RxDOS sources, binaries. Another OS: RTX, fast, multithreaded for DOS in C.
• Samsung Computer Division: Products: RxDOS Series - Instructions on making a bootable RxDOS floppy, and these files: disk image, Zip files with executable binaries (old, newest), GPL license. Useful for updating BIOS or MICOM.