Making a CompactFlash Bootable for a 386DX

[~]

I hope that this information can help somehow to understand some structure.
The interesting thing about what I wrote below is that it allows to have the Windows 98 splash screen displayed by partitioning and formatting with FreeDOS and a Windows 98 SE startup floppy disk:



I have a 386DX motherboard from around 1992.

The BIOS it has can handle disks of less than 600 Megabytes (entered manually, but corrected by MS-DOS or a capable OS by using the partition information and BIOS disk services for CHS mode).

I formatted a 4-Gigabyte CompactFlash card with an IDE adapter in this 386 machine with CHS values 899-16-63, for a partition of around 430 Megabytes.

At first I used FDISK and FORMAT from FreeDOS, but then I used a Windows 98 startup disk, also with commands FDISK and FORMAT.

From MS-DOS, I used the following command to install MS-DOS in the CompactFlash hard disk:

Code: Select all

format /S

After I formatted, I tried to boot but it didn't seem to work, so I used the following command booting from a FreeDOS floppy:

Code: Select all

fdisk /fixmbr  -- Fix the hard disk master boot record.

fdisk /mbr 1   -- Install the standard MBR in the first hard disk.
                  This is what seemed to make the trick.

With the above, I managed to make the 4-Gigabyte CompactFlash card bootable and with the Windows 98 Second Edition animated splash present. If I could patch the BIOS from DOS or from a BIOS patches floppy before booting DOS, I could access the rest of the disk in LBA mode, so I could have 4 Gigabytes in a standard CompactFlash in an old ISA 386DX motherboard.

Or I could create an OS that could be launched from a DOS shell, with LBA support.

Now I think I understand why Linux people say that it's better to have a separate boot partition, a separate root partition and data partitions: The intention here is to have a boot partition in the most compatible format of a platform. In this case, it would be a CHS partition of around 200-400 Megabytes that could be recognized by any PC BIOS, and then have an OS with drivers to access the rest of the disk directly in LBA mode without using the BIOS.


It also gave me the idea of: Why not open a floppy disk carefully, and put a thin plastic foil disc on each side of the magnetic media, and then glue it at the outer and inner disk edge so that the floppy can last for decades without degrading, just like having a hard disk media where the heads never touch the platters? If floppy disk media had been sandwiched between two hard and thin plastic discs, then floppies would have lasted as long as a CD-ROM or even a DVD.

[kzinti]

It also gave me the idea of: Why not open a floppy disk carefully, and put a thin plastic foil disc on each side of the magnetic media, and then glue it at the outer and inner disk edge so that the floppy can last for decades without degrading, just like having a hard disk media where the heads never touch the platters? If floppy disk media had been sandwiched between two hard and thin plastic discs, then floppies would have lasted as long as a CD-ROM or even a DVD.

You are an endless source of entertainment, ~. The degradation of floppy disks isn't mechanical in nature. It is chemical (oxidation) of the iron oxide that holds the magnetic information.

[~]

It also gave me the idea of: Why not open a floppy disk carefully, and put a thin plastic foil disc on each side of the magnetic media, and then glue it at the outer and inner disk edge so that the floppy can last for decades without degrading, just like having a hard disk media where the heads never touch the platters? If floppy disk media had been sandwiched between two hard and thin plastic discs, then floppies would have lasted as long as a CD-ROM or even a DVD.

You are an endless source of entertainment, ~. The degradation of floppy disks isn't mechanical in nature. It is chemical (oxidation) of the iron oxide that holds the magnetic information.

If the media had been packaged as hermetically in the same way as a DVD between two thin plastic discs to form a 3-layer disc assembled using heat, there would be no oxidation without air.

It would always be preferable to sandwich a floppy disc media between two clear discs to see how much more it lasts.

I have heard of floppies that have been used as boot media for more than 15 years, and I imagined that they could be protected like this, like this one:

YouTube: 15 years old floppy disk booting muLinux, a single 1.44Mb floppy disk distro.
YouTube: 15 years old floppy disk booting muLinux, a single 1.44Mb floppy disk distro.
YouTube: 15 years old floppy disk booting muLinux, a single 1.44Mb floppy disk distro.
YouTube: 15 years old floppy disk booting muLinux, a single 1.44Mb floppy disk distro.

[iansjack]

The loss of data on a floppy disk isn't down to mechanical or chemical reasons; it's electromagnetics. After a while the magnetic dipoles tend to get rearranged due to random fluctuations in the earth's magnetic field, passing magnetic fields, vibration (so - yes - I guess there is a mechanical element), cosmic rays, etc. You can't somehow stop this by encasing the magnetic layer in plastic. All that would do would be to make the signal received the the read/write heads that much weaker.

CDs and DVDs operate on a completely different principle to magnetic media.

Where do you get all these crazy ideas?

[Kazinsal]

OP, please just stop. Your nonsense is mind-numbing and your idiosyncratic "post every link four times" and "bold random sentences" style is just an annoyance.

Stop posting this kind of crap before new people start strolling into the forums, seeing your terrible ideas, and taking them as gospel.

[BrightLight]

OP, please just stop. Your nonsense is mind-numbing and your idiosyncratic "post every link four times" and "bold random sentences" style is just an annoyance.

+1.

[~]

The loss of data on a floppy disk isn't down to mechanical or chemical reasons; it's electromagnetics. After a while the magnetic dipoles tend to get rearranged due to random fluctuations in the earth's magnetic field, passing magnetic fields, vibration (so - yes - I guess there is a mechanical element), cosmic rays, etc. You can't somehow stop this by encasing the magnetic layer in plastic. All that would do would be to make the signal received the the read/write heads that much weaker.

CDs and DVDs operate on a completely different principle to magnetic media.

Where do you get all these crazy ideas?

But as we can see, a properly protected floppy can last for decades of use (as they should have been made from factory, although maybe a few test ones had protective transparent layers as I seem to remember, but made of some scratchable debris-less enamel).

If the magnetic data is lost, all we need is reformat at low level, but as long as the media keeps all of its magnetic material in place (as with a hard scratchless acrylic sandwich) it will keep working.

This media is also far too macroscopic as to see damage by such tiny things like neutrinos. Even hard disks of 4 to 8 Terabytes are completely immune to that, so why worry? One of those would simply pass through the floppy media without significance through the pores and spare space of each stored bit.

[iansjack]

But as we can see, a properly protected floppy can last for decades of use

Where can we see this?

This media is also far too macroscopic as to see damage by such tiny things like neutrinos.

Why have you suddenly introduced neutrinos out of nowhere? As uncharged particles which rarely interact with other particles they are, of course, highly unlikely to affect magnetic media - which is probably why no-one suggested they would. They can pass right through the earth without interacting.

The best way to protect a floppy disk is to wrap it in a Faraday cage - i.e. tinfoil. This mirrors the construction of hard disks.

The fact is that floppy disks are long since extinct. Forget about them.

[~]

But as we can see, a properly protected floppy can last for decades of use

Where can we see this?

YouTube: 15 years old floppy disk booting muLinux, a single 1.44Mb floppy disk distro.
YouTube: 15 years old floppy disk booting muLinux, a single 1.44Mb floppy disk distro.
YouTube: 15 years old floppy disk booting muLinux, a single 1.44Mb floppy disk distro.
YouTube: 15 years old floppy disk booting muLinux, a single 1.44Mb floppy disk distro.

This media is also far too macroscopic as to see damage by such tiny things like neutrinos.

Why have you suddenly introduced neutrinos out of nowhere? As uncharged particles which rarely interact with other particles they are, of course, highly unlikely to affect magnetic media - which is probably why no-one suggested they would. They can pass right through the earth without interacting.

The best way to protect a floppy disk is to wrap it in a Faraday cage - i.e. tinfoil. This mirrors the construction of hard disks.

The fact is that floppy disks are long since extinct. Forget about them.

No, I still need to use them to boot my 386DX which I use to determine if a program is using only the minimum level possible of instructions and functionality found in a 386DX with FPU so it's more portable.

So apart to buy them from Amazon and eBay I need to learn to coat the media in a way that prevents all the mechanical damage and that from mold. Then I can assume that those protected floppy disks are the default boot media for my ISA machines (and for my USB disk drives).



For exchanging data I wouldn't rely on floppies or on moving hard disks, so I need to build a parallel and serial cables for communicating through them (when using the serial mouse -a 3-button serial mouse with scroll in an ISA 386DX- I would use the parallel port for data transfer).

[Combuster]

But as we can see, a properly protected floppy can last for decades of use

Where can we see this?

<Linkspam reiterated>

That's just a regular floppy, and doesn't prove anything.

[iansjack]

I guess it probably shows that the floppy has been stored properly. It certainly seems to show that magic plastic coatings (which would stop the disk working) aren't required.

[Roman]

No, I still need to use them to boot my 386DX which I use to determine if a program is using only the minimum level possible of instructions and functionality found in a 386DX with FPU so it's more portable.

I think you could use an emulator.