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"
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VBoxManage internalcommands createrawvmdk -filename "C:\msdos\msdos.vmdk" -rawdisk \\.\PhysicalDrive1
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.