MS DOS 6.22 became read-only after installation

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B29
Posts: 1
Joined: 8. Apr 2022, 04:32
Primary OS: MS Windows 10
VBox Version: OSE other
Guest OSses: MS DOS
Location: Sunshine State

MS DOS 6.22 became read-only after installation

Post by B29 »

Hello everybody,

I am facing an issue with MS DOS 6.22 on a Windows host using VirtualBox 6.1.32.r149920. I created a raw disk from the SD card using "VBoxManage internalcommands createrawvmdkand blahblahblah" and attached it to the virtual machine. Then successfully installed MS DOS 6.22 from the standard 1.44 MB images (including format). And after the first reboot system became read-only. Every operation with disk inside of virtual machine ends up with error (various, any write/create operation). But I can write to this disk on the host.

On other hand, if I use synthetic VDI/VHD/VMDK, I can write/edit/delete files, create directories and so on. No problems at all.

This is my VMDK for the SD card:

Code: Select all

# Disk DescriptorFile
version=1
CID=a9825ebd
parentCID=ffffffff
createType="fullDevice"

# Extent description
RW 7864320 FLAT "\\.\PhysicalDrive1" 0

# The disk Data Base 
#DDB

ddb.virtualHWVersion = "4"
ddb.adapterType="ide"
ddb.geometry.cylinders="7801"
ddb.geometry.heads="16"
ddb.geometry.sectors="63"
ddb.uuid.image="2797c19e-ecd3-414f-95d9-83ff0bb05fcf"
ddb.uuid.parent="00000000-0000-0000-0000-000000000000"
ddb.uuid.modification="0c18c601-547e-4403-b22e-4c24ac091cb9"
ddb.uuid.parentmodification="00000000-0000-0000-0000-000000000000"
ddb.geometry.biosCylinders="975"
ddb.geometry.biosHeads="128"
ddb.geometry.biosSectors="63"
Command I used to create raw disk:

Code: Select all

VBoxManage internalcommands createrawvmdk -filename "C:\msdos\msdos.vmdk" -rawdisk \\.\PhysicalDrive1
Where can be the problem?

P.S. the final goal is to install Windows 95 and then use that SD card as a substitution for the real HDD in a retro PC build.
mpack
Site Moderator
Posts: 39156
Joined: 4. Sep 2008, 17:09
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Mostly XP

Re: MS DOS 6.22 became read-only after installation

Post by mpack »

B29 wrote: P.S. the final goal is to install Windows 95 and then use that SD card as a substitution for the real HDD in a retro PC build.
Rather than fight Windows drive security every step of the way, IMO it would be simpler to use VDI, then export a raw image at the end.
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