Ok, i made nt bootloader working with DR-DOS 7 virtual machine.
- i used BOOTPREP.EXE from this Rayers side http://rayer.g6.cz/os/os.htm, be aware at least Avira antivirus has false DOS virus detection for it
- when you run it, you get message that all HDD data would be destroyed, but true is that for my on FAT16 partition all data stayed on disk
- Bootprep just boot MBR code to machine, you still need manually copy/create boot.ini - file and copy bootfont.bin and ntldr and ntdetect.com from existing WinNT/2000/XP installation..
- regarding this article - https://blogs.msdn.microsoft.com/embedded/200 … using-bootprep/ , bootprep is needed for FAT16 partition and NT loader even for Windows and but it could work with FAT32 boot, but its not neded for nt bootloader.
- i created DOS boot sector with Norton Disk Editor - its described in first post save it as DRDOS.bin file
- there is my boot.ini:

1[boot loader]
2timeout=5
3default=C:\DRDOS.BIN="DRDOS7"
4[operating systems]
5multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="XP innstalation if you have one" /noexecute=optin /fastdetect
6C:\DRDOS.BIN="DRDOS7"

I finally managed to install DR-DOS 7.01 on physical machine with VIA 880 ultra chipset.. Details are added to first post.
I used MS-DOS 6.22 boot CD-ROM rom and add DR-DOS 7.01 cd installation files to it, booted from IDE CD-ROM to MS-DOS CD installation, quited to command line.. used DR-DOS fdisk (reboot needed) and after MS-DOS format utility.. after again bootem from CD rom, copied DR-DOS installation to target HDD temp directory executed installation, installed it - with errors (it probably expect to copy some files - autoexec, config and to ibm* files to c:\ root from Floppy drive).. now i had to restart from cd once more and i copied these missing files from by virtual and used ibm* files + command.com patched to FAT32, after next reboot, DR-DOS finally booted from HDD.

As HDD i used some IDE to Compact flash card Syba IDE adapter and Compact flash 16 GB. What is strange that DRDOS and MSDOS FDISK could create only 694 MB primary partition, maybe its adapter or compact flash card problem, i would be suprised, because in virtual i could to create 2 GB partition. What is important that it is working, i can see FAT32 partitions on second drive with MS-DOS 7.1 which i connected after installation. I even played Q2DOS on it, no sound for now.

To make process more user friedly i would be nice to remove IDE CD/DVD rom drive necessity, its better that have to use 5 DR-DOS floppies, but its still annoying. I tried to use USB DVD rom, but MS-DOS 6.22 installer not find it and its tried to create Freedos USB drive and run installation from it, but its not working, same as partition drive from MS-DOS 7.1, because DR-DOS fdisk is not running there. I solution for this probably exists, but dont wanted spend too much time to research it.

Next step would be backup DR-DOS bootsector and try to resize its partition. but i could probably live even with 694 MB.. and have tool to manage drive letter in DOS, because with additional disk all my patches are broken and my DATA D drive is now F. I saw some tool for it, but i never used it.

I ported my Ultimate Config files to DR-DOS they are fully compatibile with my Drivers and Tools package, which you download in my X58 thread
X58/i865/V880 - Yamaha7x4/AurealV1/2 pure Dos7.1- compatibility list/research/ultim. drivers configs, WIP- gurus needed // search for euro string second one in first post

Here is DR-DOS 7.xx it should work with all versions port:

Few notes to DR-DOS configs fom migration it could help someone else with same process:
- as with MS-DOS 6.22 and earlied BuffersHIgh, FilesHigh are not support, only BUFFERS and FILES are working
- include block is not working with DR-DOS, you have to use GOSUB command and it has to be ended with return command, same as labels
- MS-DOS Himem.sys + EMM386, JEMM, JEMMEX, QEMM and HimemX all are working with DR-DOS
- DR-DOS has not have Mode.com for faster keyboard hack so if want to use it you need to copy it from MS-DOS 6.22 / 7.1 to c:\Drivers as other MS licences files list in Drivers packaged - addfiles.txt
- i had problem with crash if Stacks line was enabled
- i had to few changes for Vmware - i had to disable Vesa font fix, otherwise EMS NOEMS mode crached, it could be Vmware bug
- the most wild was branching, menuitems are unsupported, so you have to use inbuild switch instead, maybe is there better solution and i only dont find it..
- of course i had to remove MS-DOS command.com and line and MS-DOS IFSHLP (its needed for MS-DOS file sharing, DR-DOS has own solution for it) line has to be disabled
to enable autoexec branching, you need definite config variable in config..
- because switch implemetation sucks and its limited also to 9 items max and timeout countdown is not visible.. and i want to replace item you have edit 2 lines.. i made workaround, i wanted to made all my branches still available and minimalize need for user editing.

So i made this abomination:

Logic is that at top of config files are 4 switch lines marked A/B/C/D.. you can uncomment one and comment (REM) rest to select which one you want to use for next boot. Options are marked by like 2.B / 1.D / 3.C etc.. it means that number key for specific options is related to currently valid switch line.. of course you can easily reorder options, delete options what you dont need and minimalizace number of switched or keep only 1 with 9 branches.

Otherwise first branch is DR-DOS one with enabled multitasking (i too make it usable edit taskmgr ini file in DRDOS folder and increase memory heaps, default ones are very small and get lots of crashed), any other ~20 branches are same as MS-DOS are the same. Sense is simple use 1st one for multitasking experience and other ones if you need to increase compatibility if can fix few problematic games / programs, but compatibility is already quite good, it tried to compare performance in games but with DR-DOS native its same or better, so no big deal, of course QEMM could help with squeezing more memory etc.

I was interesed about sound cards, for now i can see, that SB Live! with VIA 880 Ultra, working exactly same as with MS-DOS, there FX and FM are working, but there is cracking. Aureal V1 worked for FM i had to time test it more, but its seems that classic DOS drivers are working with DR-DOS quite well and my config using quite few of them and all seems to work at least for basic testing.

Do MS/IBM EMM386 or JEMM386 improve compatibility compared to the version from DR-DOS?

gdjacobs wrote:

Do MS/IBM EMM386 or JEMM386 improve compatibility compared to the version from DR-DOS?

I cant really say, at least now:

• because compatibility level is already pretty high
• i dont thing that i will fix major incompatility problem with FAT32
• i dont tested not working games with other than FAT32 problem with MS EMM386
• i only now that MS EMM386 only fixed not working Q2DOS timedemos, where was triggered some key press maybe some A20 gate bug (if i understand what A20 gate is)
• i suspect that MS memory managers, maybe even JEMM would improve sound cards compatibility, but again testing has to be done..

In other words some help with testing would be nice.
Only progress which i did is managed DR-DOS on 160 GB IDE hdd, with help of XFDISK and MS-DOS 6.22 enhanced boot cd.(simply added dr-dos install files and xfdisk and filemanager into ISO with WinISO free version). I still dont know if possible after DR-DOS installation, later add other partition on same HDD and keep DR-DOS working and keep special disk only for DR-DOS is annoying fo my systems.

Im now working on DOS sound cards compatibility (1,5 cards to go) and DOS videocards performance testing (majority of work is done, but switching cards is annoying), so DR-DOS is third in row, im not doing it for fame, for most readers / views etc.. but some support would be nice, if i do such thing only alone, there is very easy to fail or get stuck on some stupidity and there is not too much info sources, et least i did not find them.