HamsterOS Is Coming!

A complete desktop OS on a 1.44 MB floppy

HamsterOS is Mean Hamster Software's floppy-first 32-bit operating system for 386/486-class PCs and newer. The current build is well beyond a boot demo: it runs a managed windowed desktop, reads and writes real FAT filesystems, launches external apps, plays audio, installs to ATA hard disks, and can run DOS programs through an in-kernel VM86 path.

The master image boots through a trimmed FreeDOS wrapper and HAMLOAD.EXE, then hands off to the protected-mode HamsterOS kernel. A 2 MB machine can boot the desktop and run apps; 3 MB and up unlocks the fuller floppy experience, including the RAM disk.

What is in the current build

• Managed desktop with draggable/resizable windows, z-order focus, classic Hamster/File/Edit/Special menus, and a paged launcher toolbar
• File Manager with icon/list views, spatial folders, sorting, copy/paste, rename, delete, new folder, fast .ICO sidecars, and dynamic mounted-drive browsing
• Run dialog for mounted-drive paths such as A:\DOS\BOULDER.COM or C:\APPS\HAMWRITE.APP
• Shared bitmap system fonts: Wheel, Carrot, and Hamster, with 12/14/16/18 sizes and Regular/Bold/Italic/Bold Italic styles
• Notepad, HamsterWrite, Help Viewer, HamsterPaint, Image Viewer, HamsterPiano, CD Audio Player, Clock, Calendar, Calculator, and Preferences
• Native games including FreeCell, Video Poker, Minesweeper, Snake, Sliding Puzzle, Moon Lander, and Slot Machine
• VM86 DOS launching for .COM and .EXE files, plus a DOS toolbar prompt in A:\DOS with DIR, CD, MD, RD, COPY, REN, CLS, HELP, and EXIT
• FAT12/16/32 read/write, ISO-9660 read-only, RAM disk, Trash, safe overwrite saves, and read-back verification
• Dynamic drives: A:/B: floppies, C: through H: ATA partitions, I: through J: ATAPI CD-ROMs, and R: RAM disk
• SoundBlaster 16 PCM and OPL3 support, startup chime, notification doot, volume slider, CD audio control, and PC speaker fallback
• HAMA v1 external app format and HAMD v1 trusted loadable driver format for future hardware expansion

Install or upgrade

The boot floppy includes an Install Or Upgrade Hamster OS menu path. It can partition and format a blank ATA disk, copy the OS tree, install the FreeDOS-side boot files, run FDISK /MBR and SYS C:, and leave C: as a bootable DOS disk that auto-launches HamsterOS through HAMLOAD.EXE.

What we are working on next

The current priorities are SCSI support for period-correct ISA adapters, real-hardware display validation for banked VBE cards, HamsterWrite's native .HWD document format, installer polish, and more VM86 compatibility testing with real DOS games.

We are still targeting a public release in November 2026. Follow the HamsterOS product page for the latest feature list and project status.