VOGONS


First post, by serialShinobi

User metadata
Rank Newbie
Rank
Newbie

Hello. I am wondering about using the dd command from early Debian and the file utilities package.

My goal is to make a bootable debian live CF card. If that happens I'll likely configure networking and configure the package manager.

Then locate the package containing the dd command. I read some documentation mentioning dd was in a component called file utilities in the early editions of debian live.

Does anyone have experience with disk imaging with a live Linux distro using old versions from the 90s?

I want to dd a CF card that itself is an image of a DOS 6.22 instance. The image of DOS is raw written from virtualboxmanage internalcommands.

DD was born with ability to raw write. It should work well because it is also available as early as the first days of Linux.

My goal is mostly an experiment to see how well imaging can install an operating system.

Also to see if the virtual machine's data stays in tact while archived.

Have plans to try using a DOS based hard disk editor to examine bytes and verify.

But is there a DOS or Linux byte comparator command? Maybe a command that uses a mathematical inequality statement to see if bytes are not equal?

Can anyone suggest how to get started with setting up repos in debian live and how to search for this file utilities package I will need?

Reply 1 of 11, by lolo799

User metadata
Rank Oldbie
Rank
Oldbie

On what kind of machines will you use this bootable CF card?
Do you plan to dd the images from what source, the same card running linux, network?

PCMCIA Sound, Storage & Graphics

Reply 2 of 11, by acl

User metadata
Rank Oldbie
Rank
Oldbie

I used a similar technique several times to clone a disk from a retro system.
But I booted a lightweight Linux instead (from cd). CF will work too.

You can DD to a file, but also through the network (using netcat)
And md5sum is used to check that the saved image is identical to the physical disk.

"Hello, my friend. Stay awhile and listen..."
My collection (not up to date)

Reply 3 of 11, by serialShinobi

User metadata
Rank Newbie
Rank
Newbie

Thanks. I am using a ESA TF486 baby AT, has post DOS features such as Plug'n Play. I have no OS installed. Using a Samsung Voyager 2 3.4 GB HDD from 1997 and a Promise U33 PCI with an option ROM to over come the defunct INT13h from Phoenix BIOS.

A virtual machine disk with DOS installed is ascribed to a CF card. The host is Windows 11. The VM running a live Linux ISO in its CD drive will then image it's hard disk drive. This is later the resulting file can be stored on a single CF with debian. I can then use a single CF reader on my 486 to reverse dd onto my mechanical hard drive.

Reply 4 of 11, by serialShinobi

User metadata
Rank Newbie
Rank
Newbie
acl wrote on 2023-05-26, 19:14:
I used a similar technique several times to clone a disk from a retro system. But I booted a lightweight Linux instead (from cd) […]
Show full quote

I used a similar technique several times to clone a disk from a retro system.
But I booted a lightweight Linux instead (from cd). CF will work too.

You can DD to a file, but also through the network (using netcat)
And md5sum is used to check that the saved image is identical to the physical disk.

Thanks. This answers my questions. Now just the time it will take to realize it. Plan to break the project into steps. Worst part is of course can be the hardware but also the commands can be a lot.

Not sure about process of configuring repos. Will the package manager be uniquely difficult?

Reply 6 of 11, by serialShinobi

User metadata
Rank Newbie
Rank
Newbie
lolo799 wrote on 2023-05-26, 20:44:

You can also use a one-floppy Linux distro for the purpose, or a multi floppies rescue system, like the slackware boot and root/rescue disks:
Re: Retro OSes for retro computers

Yes the floppy is a great idea. I was just coming here to ask about weather or not I should use a full version 1.1 debian or a Linux so tiny it fits in a floppy disk image.

Nice to know there are already distributions for the floppy, and old machines. My father and also myself shortly later, installed Slackware on our 386 with Seagate 40 MB hard drive back in 1992/93.

Reply 7 of 11, by megatron-uk

User metadata
Rank Oldbie
Rank
Oldbie

dd is dd is dd, whether you use it from a 1996 Slackware install, a SunOS version or something from a modern Ubuntu.

What is the purpose of comparing bytes?

If you want to just compare a byte range to another byte range you can extract using DD from one offset and then use diff (with the binary flag) to see if it the same as the other.

A better method is to calculate the checksum of one range of bytes/disk image/file/archive and then compare with what you wrote back.

None of what you are listing is new, and has been done many times before. I can assure you it all works!

My collection database and technical wiki:
https://www.target-earth.net

Reply 8 of 11, by serialShinobi

User metadata
Rank Newbie
Rank
Newbie
megatron-uk wrote on 2023-05-27, 19:12:
dd is dd is dd, whether you use it from a 1996 Slackware install, a SunOS version or something from a modern Ubuntu. […]
Show full quote

dd is dd is dd, whether you use it from a 1996 Slackware install, a SunOS version or something from a modern Ubuntu.

What is the purpose of comparing bytes?

If you want to just compare a byte range to another byte range you can extract using DD from one offset and then use diff (with the binary flag) to see if it the same as the other.

A better method is to calculate the checksum of one range of bytes/disk image/file/archive and then compare with what you wrote back.

None of what you are listing is new, and has been done many times before. I can assure you it all works!

Yes, it's not original, but I am trying to apply my familiarity with command line keywords to learn more about programming in the shell.

A comparison can teach me how to find data that was corrupted while trying to build a retro computer.

Thanks for sharing some of these methods of using the dd program to compare bytes.

Reply 9 of 11, by jtchip

User metadata
Rank Member
Rank
Member

If you plan to boot Debian on the 486, the last version with 486 support is 5/lenny. The repositories have long since been archived (as has everything older than Debian 10). After installation (remember to install the 486 kernel) you have to change /etc/apt/sources.list to point to the archive repository:

deb http://archive.debian.org/debian lenny main
deb http://archive.debian.org/debian-security lenny/updates main non-free

To compare files, you can also use cmp, perhaps with the -b or -l option. It's part of the diff package, along with diff itself. This is an essential package and is installed by default, in fact dpkg warns you if you try to remove it.
Comparing checksums could take noticeably longer on an old machine.

Last edited by jtchip on 2023-05-29, 00:52. Edited 1 time in total.

Reply 10 of 11, by serialShinobi

User metadata
Rank Newbie
Rank
Newbie

Thank you. This was invaluable. Threw away all the disks I made that were later or earlier than version 5. Will be spared the (always) long search to get the repos working. Thanks.

Reply 11 of 11, by Pierre32

User metadata
Rank Oldbie
Rank
Oldbie

Just to add, since I've been playing with old Debian installs in recent weeks: If you're doing a net install and you're prompted to manually provide a mirror during that process, simply enter in the two fields:

archive.debian.org
/debian/

Then you can make the full changes to sources.list afterwards as described by @jtchip. Took me way too long to figure that out.