APsOS

Another PC semi-OS

What‘s that?

It‘s an another MS-DOS-based OS for retro (and not so) computers running MS-DOS. Think of it as of a successor (but not based on) for Windows 9x.

Project goals

• Recreate Windows 9x's interface
• Make it bluescreen about as often as 9x does
• Make it support DOS programs and some Windows ones (optional goal, doesn't have to be accomplished)

Requirements

	Minimal	Recommended
CPU	i386	Intel Pentium
RAM	1MB	24MB
HDD	50MB	2GB
GPU	VGA MODE X compatible

Other software requirements

Software	Purpose/Description	Requirement level	Use instead of	Notes	Direct download links	License	Source code download links (if not proprietary)
MS-DOS 6.22 (or maybe older, didn't really test — but I think higher than 4.00)	Backend, bootloader, compatibility layer, drivers, API provider	Absolutely required	—	FreeDOS and older versions of MS-DOS may work as well, not tested	From Microsoft, no legal way currently	Proprietary, for versions 1.00, 3.00 and 4.00 — MIT	Here
MOUSE.COM	Mouse input	Absolutely required	—	No navigation without it, plus why would you use a GUI without a mouse?	Bundled with MS-DOS	Proprietary
HIMEM.SYS	High memory manager	Very highly recommended	—	More RAM is usable. On PCs with lots of RAM, use /TESTMEM:OFF, or else it will hang	Bundled with MS-DOS	Proprietary
HIMEMX.EXE	Better high memory manager	Very highly recommended	Use instead of HIMEM.SYS.	Fixes its bugs.	Here	GPL	Here
Cutemouse	Better mouse input driver, more features than mouse.com	Very highly recommended	Use instead of MOUSE.COM.	Supports mice with wheel	Here	GPLv2	Here
HIMEMSX.EXE	"Super" high memory manager (supports even more RAM than HIMEMX does)	Highly recommended	Use instead of HIMEM.SYS and HIMEMX.EXE.	Allows for even more RAM, up to 1TB	Here	GPL	Here
SBEMU	Sound Blaster 1.0, Sound Blaster 2.0, Sound Blaster Pro, Sound Blaster Pro2, Sound Blaster 16 (8-bit and 16-bit DMA (mono, stereo, high-speed modes)), OPL3 emulator for modern sound cards like Intel ICH / nForce / SIS 7012, Intel High Definition Audio (HDA), VIA VT82C686, VT8233/37, SB Live! / Audigy, SB Audigy LS (CA0106), Ensoniq ES1371/1373, C-Media CMI8338/8738	Recommended on modern PCs with AC‘97 or Intel HDA sound chips	—	Emulates the Sound Blaster. For memory management, use the second method with JEMM386. Download the version v5.84 of JEMM386 from here (starts a 123KB download)	Here	GPLv2	Here

Building and testing

Below the instructions for building and testing the project are listed. Please follow them to ensure that the project builds and then runs correctly.

Building

Below the instructions for building the project are listed. Please follow them to ensure that the project builds correctly.

Prerequesites

Program	Purpose/Description	Requirement level	Notes	Direct download links	License	Source code download links (if not proprietary)
Open Watcom v2.0	Compiler + IDE	Absolutely required	—	Open Watcom	Custom license	Open Watcom
Visual Studio Code	IDE	Recommended	You can use Open Watcom's code editor instead	Here	Proprietary	—

Building

1. Navigate to the Open Watcom installation directory
2. Go to binnt64 directory
3. Launch "ide.exe"
4. Open project
5. Navigate to the repo folder and open "AGDS.wpj"
6. Build Source
7. Build Target
8. Done!

Testing

Prerequesites

Just copy-pasted from section "Other software requirements"

Software	Purpose/Description	Requirement level	Use instead of	Notes	Direct download links	License	Source code download links (if not proprietary)
MS-DOS 6.22 (or maybe older, didn't really test — but I think higher than 4.00)	Backend, bootloader, compatibility layer, drivers, API provider	Absolutely required	—	FreeDOS and older versions of MS-DOS may work as well, not tested	From Microsoft, no legal way currently	Proprietary, for versions 1.00, 3.00 and 4.00 — MIT	Here
MOUSE.COM	Mouse input	Absolutely required	—	No navigation without it, plus why would you use a GUI without a mouse?	Bundled with MS-DOS	Proprietary
DOSBox	DOS Emulator	Absolutely required	—	As an alternative, test on real hardware or with a VM with real DOS (no instructions here)	Here
HIMEM.SYS	High memory manager	Very highly recommended	—	More RAM is usable. On PCs with lots of RAM, use /TESTMEM:OFF, or else it will hang	Bundled with MS-DOS	Proprietary
HIMEMX.EXE	Better high memory manager	Very highly recommended	Use instead of HIMEM.SYS.	Fixes its bugs.	Here	GPL	Here
Cutemouse	Better mouse input driver, more features than mouse.com	Very highly recommended	Use instead of MOUSE.COM.	Supports mice with wheel	Here	GPLv2	Here
HIMEMSX.EXE	"Super" high memory manager (supports even more RAM than HIMEMX does)	Highly recommended	Use instead of HIMEM.SYS and HIMEMX.EXE.	Allows for even more RAM, up to 1TB	Here	GPL	Here
SBEMU	Sound Blaster 1.0, Sound Blaster 2.0, Sound Blaster Pro, Sound Blaster Pro2, Sound Blaster 16 (8-bit and 16-bit DMA (mono, stereo, high-speed modes)), OPL3 emulator for modern sound cards like Intel ICH / nForce / SIS 7012, Intel High Definition Audio (HDA), VIA VT82C686, VT8233/37, SB Live! / Audigy, SB Audigy LS (CA0106), Ensoniq ES1371/1373, C-Media CMI8338/8738	Recommended on modern PCs with AC‘97 or Intel HDA sound chips	—	Emulates the Sound Blaster. For memory management, use the second method with JEMM386. Download the version v5.84 of JEMM386 from here (starts a 123KB download)	Here	GPLv2	Here

Testing

Note

This section isn't written yet

Contributing note

„APsOS“ and the APsOS logo are trademarks of Andrei „ProximalElk6186“ Kot. While „APsOS“‘s source code is licensed as MPL 2.0, you may not use the name „APsOS“ or the project‘s logo for modified versions or redistributions without explicit written permission from the trademark owner.

THEREFORE, AS FOUNDER AND COORDINATOR OF THE 'APsOS Project' [ESTABLISHED MAY 2025, FIRST USED IN COMMERCE (WEB SITE) 26-May-2025], I HEREBY MAKE TRADEMARK CLAIM TO THE NAME, LOGOTYPE OF 'APSOS' AS IT RELATES TO ``computer operating system software to facilitate computer use and operation''. DATED 26-MAY-2025. SIGNED ANDREI KOT.

Looks official I guess

Trademarks and registered trademarks note

All trademarks are intellectual rights of their respective owners.