Found a X-DOS 5.2 kernel here https://archive.org/download/ipadDOS not sure it's the latest...

Next
X-DOS 5.2 from HBS isn't included:
-It didn't support multiconfig commands
-The boot managers I test didn't work (BOOT, MCONFIG, MULTICNF)
-It didn't support the Candyman Multi Bootsector loader.
-The RAMDISKes I use didn't work (XSMDSK, RDISK)

ZDOS 1.68 y ZEBOR Technology isn't included:
-It didn't support multiconfig commands
-The boot managers I test didn't work (BOOT, MCONFIG, MULTICNF)
-The RAMDISKes I use didn't work (XSMDSK, RDISK)

Just for the record, both ZDOS and X-DOS are neat.
They just don't mimic MS-DOS in every aspect, but do their own thing.

X-DOS has built-in XMS support, a colourful CLI and some internal graphical utilities (external utilities missing in 'free' versions).

ZDOS is a 32-Bit OS meant to be run in tandem with the 32-Bit ZBIOS, to ideally run its own 32-Bit applications.
16-Bit DOS programs are supported in some dedicated VM.

To give an idea:

ZBIOS exels in disk I/O which dramatically decreases the time spent booting an OS.
As an example, our floppy disk emulator used for CD-ROM/DVD booting reads data more than 53 times faster on a 133MHz 486-based board when compared to a 1.5GHz Athlon XP with a standard BIOS.

ZDOS was developed as a 32-bit replacement of 16-bit DOS,
but with modern features like multi tasking, demand paging, SMP etc..

ZDOS is fully backward compatible with 16-bit applications using BIOS and DOS APIs.
These BIOS and DOS calls are handled entirely by 32-bit code,
leaving more memory available between 640K to 1MB, since ZDOS maps locations used by the 16-bit BIOSes to upper memory blocks.

Old 16-bit applications runs in their own virtual machines in parallell with 32-bit processes.

No offense, but this thing is from 20 years ago and has more sophistication than FreeDOS has now.
Imagine how great and fun DOS as a platform would be now if something like ZDOS have had a community.

With ZDOS you can do every thing you used to do, but now in a full 32-bit, multitasking environment.
You can create 32-bit, multi tasking processes with a lot of threads, invoking safe reentrant 32-bit BIOS and DOS API calls.

PS: To those who may think that this is just a footnote in history..

[..] In October, six Stockholm-based companies were selected to take part in an event in Hong Kong where Chinese investors, indu […]
Show full quote

[..]
In October, six Stockholm-based companies were selected to take part in an event in Hong Kong where Chinese investors,
industry players and reporters met with Swedish cleantech entrepreneurs.

The companies came from a diverse range of industries including clean technology solutions in renewable energy,
waste management and construction, as well as computer engineering.

[..]
One of the companies was Zebor Technology, which has developed the fastest, most cost-effective and scaleable platform for embedded systems based on the products ZDOS and ZBIOS.

Source: https://scandasia.com/9985-china-seeks-swedis … tech-expertise/

The problem seems to be you are restricting yourself to 4DOS and MS-DOS multi-config commands and certain boot managers. This excludes many of DOSes out there that have many non-MS-DOS features/novelties. A pity, but cool exercise anyway.

There is no problem, first my project is a floppy with as much kernels I can put on it with a switching system.
Second all kernels must use the same command interpreter in order to have a common base for comparison or the results will not valid.
Third a boot manager is needed for ease of use as I have 37 memory managers couple.

Fell free to request the boot disk in PM to try it and fully understand my project.

So I notice MS-DOS 8.0 has a newer Himem, version 3.99. Win95/98 use version v3.95.
Anyone know the differences (like more optimized memory?). Can himem.sys from Dos 8.0 be extracted and used as a standalone Himem.sys.

Riikcakirds wrote on 2025-05-03, 15:01:

So I notice MS-DOS 8.0 has a newer Himem, version 3.99. Win95/98 use version v3.95.
Anyone know the differences (like more optimized memory?). Can himem.sys from Dos 8.0 be extracted and used as a standalone Himem.sys.

Not sure it's better, from my point of view, it was done to limit user memory modification and ensure system stability.

I'm not sure it's possible to extract it, it will lack a load of standalone need... only solution I think about is to find the hex part in IO.SYS and injecting in the previous himem but it has 99% chance of failure...

Some links to prepare your deep dive:
http://www.multiboot.ru/msdos8.htm
https://msfn.org/board/topic/183250-how-to-di … dows-mes-iosys/
https://msfn.org/board/topic/77019-windows-me … nbootsys-format

Hi, it's always about MS-DOS, but what about himem.sys of IBM PC-DOS 2000 or 7.x?
Doesn't it support newer things like Fast A20?

Jo22 wrote on 2025-05-03, 20:29:

Hi, it's always about MS-DOS, but what about himem.sys of IBM PC-DOS 2000 or 7.x?
Doesn't it support newer things like Fast A20?

Hi, I don't have the info nor the technical level to answer.

You may ask to Erdogan Tan (https://www.singlix.com/contact.html) who work lately on a reverse engineering version of PC-DOS (https://github.com/turkishrational/retrodos/t … /main/retrodos5), maybe he can answer?

You may also check this: https://msfn.org/board/topic/186014-the-packa … re-in-himemsys/

Hi, many thanks for the information! ^^

NEXT
PC-MOS 5.02 (https://github.com/roelandjansen/pcmos386v501) isn't included:
-It didn't support multiconfig commands
-The boot managers I test didn't work (BOOT, MCONFIG, MULTICNF)
-Cannot manage to load 4DOS from a sub directory
-Unstable/crach with JEMMEX and others

^PC-MOS/386 isn't a normal DOS. It's its own multiasking/multi-user OS with DOS 5 compatible ABI.
QEMM and EMM386 can't work here, of course. It's a different kind of OS that uses V86 for its own purpose.
It also needs some properly configured autoexec.bat and config.sys to fully work.
My sample config, needs adjustment:

Autoexec.bat/Config.sys (examples; not complete. $serial.sys missing, etc.) […]
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Autoexec.bat/Config.sys
(examples; not complete. $serial.sys missing, etc.)

[Autoexec.bat]
set COMSPEC=A:\COMMAND.COM
.envsize 384
.echo off
path A:\
.prompt [TASK $i - $p]

[Config.sys]
MEMDEV=A:\$386.SYS
smpsize=48K
device=A:\PCTERM.SYS
device=A:\ELTERM.SYS
device=A:\$KBGR.SYS
device=A:\$NETBIOS.SYS TASKS=03
CACHE=4096,16
country=049
shell = A:\command.com

Older versions such as v3 run on 8086 and 80286, too, at least.
In my channel, there are some sample videos.
However, they are limiting PC-MOS/386 in what it can do (lack of extended memory, V86 etc).
There's an external MMU for 286 PCs that can support PC-MOS/386 to leviatate it to 386 level.
Via ADDTASK it's possible to add another DOS console session.
Using ALT+number switches between programs/consoles, if memory serves.
PS: I didn't mean to annoy you, but I simply grew up with PC-MOS. My dad used to use v3 and earlier.

Jo22 wrote on 2025-05-16, 19:25:

PS: I didn't mean to annoy you, but I simply grew up with PC-MOS. My dad used to use v3 and earlier.

Hi, sharing valuable informations and memories is never annoying.
Inded it's precious and welcome. Thanks a lot