windows 10 img format

[muta...@gmail.com]

I just discovered that you can double-click on an .img
file in Windows and it will attempt to mount it as a
virtual disk.

But so far I haven't been able to find out what format
it is expecting.

I think I used this command to do conversion before:

qemu-img dd -O vmdk if=pdos.img of=pdos.vmdk

but no longer required conversion.

I'm happy to convert to Windows image format for
a hard disk image and/or a floppy disk image when
I find out what it actually is.

Anyone know?

Thanks. Paul.

[Alexei A. Frounze]

CD and DVD images AFAIK.

Alex

[Joe Monk]

On Friday, July 9, 2021 at 11:13:18 PM UTC-5, muta...@gmail.com wrote:
> I just discovered that you can double-click on an .img
> file in Windows and it will attempt to mount it as a
> virtual disk.

>But so far I haven't been able to find out what format
>it is expecting.

Even better, you can right click an ISO and it will mount it also as a virtual CD/DVD.

"The .img filename extension is used by disk image files, which contain raw dumps of a magnetic disk or of an optical disc. Since a raw image consists of a sector-by-sector binary copy of the source medium, the actual format of the file contents will depend on the file system of the disk from which the image was created (such as a version of FAT). Raw disk images of optical media (such as CDs and DVDs) contain a raw image of all the tracks in a disc (which can include audio, data and video tracks). In the case of CD-ROMs and DVDs, these images usually include not only the data from each sector, but the control headers and error correction fields for each sector as well.

Since IMG files hold no additional data beyond the disk contents, these files can only be automatically handled by programs that can detect their file systems. For instance, a typical raw disk image of a floppy disk begins with a FAT boot sector, which can be used to identify its file system. Disc images of optical media are usually accompanied by a descriptor file which describes the layout of the disc, and includes information such as track limits which are not stored in the raw image file."

https://en.wikipedia.org/wiki/IMG_(file_format)

Joe

[muta...@gmail.com]

On Saturday, July 10, 2021 at 7:08:38 PM UTC+10, Joe Monk wrote:

> The .img filename extension is used by disk image files, which contain raw dumps of a magnetic disk or of an optical disc. Since a raw image consists of a sector-by-sector binary copy of the source medium, the actual format of the file contents will depend on the file system of the disk from which the image was created (such as a version of FAT).

> Since IMG files hold no additional data beyond the disk contents, these files can only be automatically handled by programs that can detect their file systems. For instance, a typical raw disk image of a floppy disk begins with a FAT boot sector, which can be used to identify its file system.

> https://en.wikipedia.org/wiki/IMG_(file_format)

Thanks for the link. I did a search for "windows" but didn't
get what I wanted.

Unfortunately Windows 10 is rejecting raw floppies and
raw hard disks (both .img), that work under Bochs and Qemu.

Hence my question.

Mounting .iso CD/DVD is not useful to me at the moment.

BFN. Paul.

[Joe Monk]

> Unfortunately Windows 10 is rejecting raw floppies and
> raw hard disks (both .img), that work under Bochs and Qemu.

you need winimage.

http://www.winimage.com/winimage.htm

Joe

[muta...@gmail.com]

That doesn't mention that it can create image files that
Windows 10 can handle.

I'm after something Windows 10 can handle. Once Microsoft
starts supporting mounting floppies or hard disks, I will find
a converter to put it into a Microsoft-supported format.

Quite odd that it's 2021 and Microsoft doesn't support that.
Maybe their developers don't know how to write Windows
drivers or something.

BFN. Paul.

[Joe Monk]

> Quite odd that it's 2021 and Microsoft doesn't support that.
> Maybe their developers don't know how to write Windows
> drivers or something.

Or maybe it's 2021 and PC's aren't made with floppy drives anymore, so the support has been removed.

Joe

[Joe Monk]

> That doesn't mention that it can create image files that
> Windows 10 can handle.

WinImage 10.0 is compatible with WinImage 8.x translation file. Version compatible until Windows 10 and Windows server 2019

https://www.winimage.com/download.htm

Joe

[muta...@gmail.com]

On Saturday, July 10, 2021 at 9:34:49 PM UTC+10, Joe Monk wrote:

>> Quite odd that it's 2021 and Microsoft doesn't support that.
>> Maybe their developers don't know how to write Windows
>> drivers or something.

> Or maybe it's 2021 and PC's aren't made with floppy drives
> anymore, so the support has been removed.

They're still made with hard disks, but I can't feed Windows 10
a hard disk image it seems.

> > That doesn't mention that it can create image files that
> > Windows 10 can handle.

> WinImage 10.0 is compatible with WinImage 8.x translation file.
> Version compatible until Windows 10 and Windows server 2019

Being compatible with itself is not what I'm after. I'm after
something Windows 10 natively recognizes.

BFN. Paul.

[Joe Monk]

> Being compatible with itself is not what I'm after. I'm after
> something Windows 10 natively recognizes.

VHDX or ISO.

Joe

[muta...@gmail.com]

Thanks! This was very promising. I ran this command:

qemu-img dd -O vhdx if=hd2.img of=testq.img

to convert my 1 GB FAT-16 to vhdx format, but still got the
usual complaint about the img file when I tried to mount it.

Then I tried renaming .img to .vhdx and I got a different
error message about needing an uncompressed NTFS
directory.

I did a file, properties, advanced on my "bochs" directory
(with the .vhdx in it) and it is not compressed. And the
drive, the C drive, is local and NTFS, as per file, properties
on the drive.

According to Wikipedia:

https://en.wikipedia.org/wiki/VHD_(file_format)

VHD can be mounted by Windows 7 (and presumably
successors?), but they didn't explicitly mention VHDX.

Unfortunately qemu-img doesn't support VHD.

Maybe I need to write my own img to VHD converter.

But is there light at the end of the tunnel?

BFN. Paul.

[Joe Monk]

> to convert my 1 GB FAT-16 to vhdx format, but still got the
> usual complaint about the img file when I tried to mount it.
>
> Then I tried renaming .img to .vhdx and I got a different
> error message about needing an uncompressed NTFS
> directory.

you skipped some steps.

here's a little help for you... https://www.tenforums.com/tutorials/138380-create-set-up-new-vhd-vhdx-file-windows-10-a.html

Joe

[muta...@gmail.com]

Thankyou sir!

The secret on that link was to start diskmgmt.msc from
the command prompt (I didn't need to have an
administrator prompt).

But I needed to click on the C drive before it would let
me do an action, create VHD.

I was able to set up a FAT-16 LBA partition, save a test
file, convert to .img with:

qemu-img dd -O raw if=testf.vhdx of=testg.img

and Bochs accepted that. Bochs can't handle the vhdx
though.

Unfortunately I can't convert back, the resulting .vhdx is
not accepted even under action, attach VHD, I think there
might be something technically wrong with qemu-img.

Also, when Bochs was inspecting the image, the name
of the partition displayed correctly under Freedos "dir",
but the name of the disk in fdisk was garbled - presumably
coming from the MBR.

Let me see what possibilities this opens up. I'm thinking
I can bypass Freedos.

Thanks. Paul.

[Joe Monk]

> and Bochs accepted that. Bochs can't handle the vhdx
> though.
>

VHDX is for Hyper-V Server 2019. Use VHD instead. Same format.

Joe

[muta...@gmail.com]

I was skeptical, but this is fantastic. If I create a VHD,
it is accepted by Bochs. It seems that it is a raw hard
disk image followed by 512 bytes, according to this:

https://en.wikipedia.org/wiki/VHD_(file_format)

I was surprised though - initializing and formatting a
VHD creates an MBR, but does not create a VBR with
a 55AA signature.

Yet the file system is usable by Windows. Not to boot
though.

But I have been relying on the contents of the VBR to
tell me how many bytes per sector there are etc.
How can you cope without a BPB???

BFN. Paul.

[Rod Pemberton]

On Fri, 9 Jul 2021 21:13:17 -0700 (PDT)
"muta...@gmail.com" <muta...@gmail.com> wrote:

> I just discovered that you can double-click on an .img
> file in Windows and it will attempt to mount it as a
> virtual disk.
>

Windows 10 can mount .iso and .img image files. .iso is for optical
CD/DVDs images, i.e., ISO 9660. .img files are for floppy disk images,
and can be either compressed or not.

Windows usually supported ISO 9660 extensions like Rock Ridge, Joliet,
and El Torito.

Some versions of Windows can mount .zip files.

Various M$ OSes support file systems NTFS, exFAT, FAT, UDF, CDFS (ISO
9660).

The only CD formats that I've used with Windows are ISO 9660, ISO 9660
w/ Joliet, and UDF.

If the other format Joe mentioned works for you, that's great, but it
probably won't work on older OSes, including older versions of Windows.

--
The Chinese have such difficulty with English ... The word is not
"reunification" but "revenge".

[muta...@gmail.com]

On Tuesday, July 13, 2021 at 1:27:25 AM UTC+10, Rod Pemberton wrote:

> CD/DVDs images, i.e., ISO 9660. .img files are for floppy disk images,
> and can be either compressed or not.

If I could mount floppies, that would be fantastic too. But
I just tried to mount a raw floppy, and it said that my
image was corrupt. What format does Windows support?
I have this available:

Supported formats: blkdebug blklogwrites blkreplay blkverify bochs cloop copy-on-read dmg file ftp ftps host_device http https luks nbd null-aio null-co parallels qcow qcow2 qed quorum raw replication sheepdog throttle vdi vhdx vmdk vpc vvfat

Or does Windows 10 provide a way to create a floppy?

> Windows usually supported ISO 9660 extensions like Rock Ridge, Joliet,
> and El Torito.

It appears I have no interest in CDs because there is no BIOS
call to access them. Or maybe there is, in which case maybe
I'll add support for them.

> If the other format Joe mentioned works for you, that's great, but it
> probably won't work on older OSes, including older versions of Windows.

At that level I don't need it to work on older versions of
Windows. I support older versions of Windows at the
PDPCLIB-based application level, not this level. I provide
a route for people to upgrade from unsupported Win95
to supported PDOS/386.

In particular, if Win95 users are nervous about that, my
desire is to boot from USB stick, leaving the Win95
(or whatever) installation undisturbed.

I'm particularly interested in computers that have had
a hard disk crash and it costs too much to replace, but
booting from USB is an option.

BTW, the VHD format can still be burned using Win32
Disk Imager to USB stick and booted on real hardware.
That was tested last night.

That means that the only software that needs to be
installed on a Windows 10 PC is Win32 Disk Imager.
Plus maybe Bochs if you have a crappy BIOS. And
someone needs to create a proper hard disk image
using Freedos, but I have already done that and put
it on my website. Everything else you need (ie a C
compiler mainly) can be downloaded from my website.

"zip" would be good too, and is now in focus.

Does Windows not have something to replace Win32
Disk Imager? I wonder how difficult it is to write a
a command line program to do what it does. Copy a
file, basically. How difficult has that been made?

Oh, you also need Bochs to access the internet
while waiting for Jens to carpet-bomb Taiwan.

Probably a Freedos image would be good for the
time being though. It will still be a while before a
32-bit public domain version of fdisk using ANSI
escape sequences is available. And even longer
before Open Watcom is available.

But everything above has source code, although it
won't work with gccwin, or at least the windows.h
that comes with PDOS. But recent experience with
micro-emacs suggests that maybe that is not too
difficult to add, if you still continue to use
Microsoft's kernel32.dll and msvcrt.dll.

Oh, and Open Watcom needs to be installed too,
eventually, probably running under Freedos, to
build IO.SYS.

The vague goal appears to be to wean the development
environment off Windows and onto Freedos, which could
then be booted stand-alone from USB stick.

Freedos+HX+doslfn+PDPCLIB-msvcrt.dll has everything
that is required if you have a working serial port and
modem. Oh, you also need a computer with two or
preferably 3 USB sticks that turn into hard disks. The
computer that I am experimenting on doesn't seem to
be able to cope with the 3rd USB stick. On top of
returning a value of 1 for BosFixedDiskStatus(), which
I have learnt to ignore. Also it seems the second hard
USB stick needs more than 5 retries with BosDiskReset()
being done, some of the time. 500 retries stops the
intermittent failure, but causes bootup to take several
minutes when the 3rd USB stick, 4th drive, given that
the real hard disk is included, is accessed and either
unavailable or available but unsupported.

I really wasn't expecting even 1 retry to be necessary
for a USB stick emulating a hard disk. Nor a parameter
error for doing a status. The hard disk doesn't get that
error. I think that because most OSes (but MSDOS does)
don't use the BIOS, no-one has spent effort creating a
robust BIOS. But I would like effort spent making great
BIOSes/UEFI. Or for the functionality to be flashable.
Flash part of Linux onto an SD card inside the computer.
Let the computer manufacturers take the risk of using
virus-licensed copyrighted software.

BFN. Paul.

[muta...@gmail.com]

On Tuesday, July 13, 2021 at 5:51:30 AM UTC+10, muta...@gmail.com wrote:

> The vague goal appears to be to wean the development
> environment off Windows and onto Freedos, which could
> then be booted stand-alone from USB stick.

I know what it is.

I don't want the user to install software. I want to create
a disk image with the development environment already
installed.

I would be happy to do that with Windows, but Windows
is not free.

I don't want the user to have to install Cygwin baggage.
But if the baggage (or equivalent) comes pre-installed
on either Windows or a Freedos distribution, that is fine.

Having a C:\PATH on Windows and copying individual
executables from vendors into that is fine though.

And having the exact same C:\PATH under Freedos is
also fine, albeit not commercial quality

And having the exact same C:\PATH under PDOS/386
is also fine, but not even at Freedos's level of quality.
But people can pick this environment up and use it as
a base, unrestricted, to potentially create a commercial
quality competitor to the above commercial quality
distribution.

Some jackass ex-US-president, Carter I think it was,
said "let the debate begin" (on Israel/Palestine, as if
there had been no debate on this topic before his
stupid book).

So now I say "let the competition begin". Chabbie/386
is less than 24 hours old and linked to from
http://pdos.org
It is being advertised as the best OS in the world.
Personally I think it still needs some work, but who
am I to judge? Her offering is superior to mine
after all. I noticed that her OS doesn't come with
source code, but I happen to know that no-one is
going to sue her because of that.

As Con the Fruiterer used to say "good luck with your
family" (or something like that).

BFN. Paul.

[muta...@gmail.com]

On Saturday, July 10, 2021 at 7:08:38 PM UTC+10, Joe Monk wrote:

> On Friday, July 9, 2021 at 11:13:18 PM UTC-5, muta...@gmail.com wrote:
> > I just discovered that you can double-click on an .img
> > file in Windows and it will attempt to mount it as a
> > virtual disk.
>
> >But so far I haven't been able to find out what format
> >it is expecting.

> Even better, you can right click an ISO and it will mount it also as a virtual CD/DVD.
>
> "The .img filename extension is used by disk image files,

I'm back to this again.

As previously reported, I've made massive progress
with VHD, and that is under control except I don't know
how to get Windows 10 to natively burn a VHD to USB
stick and instead need to use Win32 Disk Imager.

IMG I still don't know what Win 10 is happy to accept.

But my interest right at the moment is ISO CDROMs. My
current Dell laptop doesn't have a CD/DVD at all, but my
previous Dell (still working) does. I think my previous Dell
is running Win 10 but I can't remember for sure.

I am about to obtain some old software on a CDROM and I'd
like to create an ISO image of it so that I can mount it on my
CDROM-less new laptop. I can fire up my old laptop, put the
CDROM in there, and then do WHAT to create an ISO image?
Is there any software that comes with Win 8/10 to create an
ISO image? If not, do I need to see if Win32 Disk Imager or
some other software is happy to create an image?

I can transfer the ISO image over to my new machine via
USB stick because I don't trust a connection to the internet
to not destroy my mostly-working old laptop via perpetual
updates. I'll power off my router to ensure there is no
connection made.

Thanks. Paul.