The udos project

Overview

• udos is a micro disk operating system for PC/AT compatibles with legacy floppy drive.
• udos is bootable from legacy FDD and has no access to HDD.
• udos is really small; about 5,000 lines in C and assemby code.
• please see README in udos-0.0.3.tgz for details.

Screen snapshots

• udos on Thinkpad 240 Type 2609
• udos on Bochs-2.1.1
• udos on Vmware-4.0.0
• (udos also runs on Parallels Build 3188.)

Download

• udos-0.0.3 source code (700KB), gzipped udos floppy image (70KB) (a very minor bug in FAT12_sync was fixed)
• udos-0.0.2 source code (700KB), gzipped udos floppy image (70KB)
• patch for udos-0.0.2 that allows you to build udos on Linux and MacOS X, and run udos on QEmu. Please read README (in Japanese).

Published papers

• Software engineering aspects of educational operating systems -- through the development of udos --, K. Gondow and M. Ohba, FOSE2004, 2004. (In Japanese) pdf ppt
• Design and Implementation of Compact Educational Operating System udos by Practice of Middle-level Abstraction, Thin Middle Layers and Traceability, K. Gondow and M. Ohba, The Transactions of the Institute of Electronics, Information and Communication Engineers, J90-D[5], pp.1194-1208, 2007. (In Japanese)

Links

• picos: pico size operating system