But, why do IMAGING on PC-DOS disks?
On Thu, 3 Nov 2022, Grant Taylor via cctalk wrote:
My /personal/ and primary use case is for use in virtual machines where disk
images (a la dd) is best (in my experience).
THAT is a totally valid reason for disk images, rather than file copies.
Another, less common problem, is that SOME installation programs also look
at the disk label, in addition to the files.
Windoze, at least in 3.xx did not. It worked fine to copy everything to a
single directory and install from there.
Other than bootable or copy-protected, then re-creation is format a disk
and copy the files onto it.
I largely agree. However being a person that plays with different operating
systems in virtual machines, I need to boot and / or readily attach images to
the VM.
Ah, if you are using OS's other than MS-DOS and PC-DOS, then a disk image
is likely to be essential.
Even the 5150 also had CP/M-86 and UCSD P-System FROM IBM.
And the 5170 had Xenix (Santa Cruz Operation Unix, peddled through
Microsoft)
In what way would "better than DD" be needed?
I'm too ignorant to be able to answer that. dd has served /my/ needs.
However I think there is some consensus, I don't know how general it is, that
dd or simple file copy tends to not be sufficient for some things.
The USUAL reasoning is to reproduce variance other than content of sectors
and files. Such as copy-protection.
Unless you are dealing with copy-protection, or seriously alien formats,
you are generally better off using the FDC to make your images, rather
than flux-transition. There are numerous FDC based imaging programs, but,
there are also multiple formats of the image, such as metadata headers,
etc.
OTOH, flux-transition lets you look at content below the sector level, to
view and sometimes even repair damaged tracks.
I believe it's technically possible to re-create an MS-DOS boot disk by
formatting and then copying IO.SYS, MSDOS.SYS, and then COMMAND.COM to the
floppy disk in that order. I think the same methodology can be used with
PC-DOS. But that's /just/ /DOS/ and doesn't cover boot disks for other
operating systems that I play with.
Even with MS-DOS/PC-DOS, there CAN [very rarely] be issues of boot sector.
OS other than MS-DOS/PC-DOS likely need an image. SOME OS use system
tracks and/or content that is NOT stored as files in the DIRectory.
--
Grumpy Ol' Fred ci...@xenosoft.com
