How to un-Initialise a disk

Foolishly, I ran !HForm to initialise an SD Card without my glasses on and got drive 4 instead of drive 0.

The disc is a USB connected mSATA zapped with !HForm.

Is the any software which will un-initialise it?

Might be worth trying DiscKnight but I’m not sure how successful it would be. It’s the only thing I can think of that might stand a chance. There’s a free ‘checker’ version of it here so at least you have a rough idea of whether it will work before you buy it (although I do find DiscKnight to be an indispensable tool).

Back in the day, I think I used Sergio Monesi’s FSCK to fix issues, but I’m fairly sure that’s too old to work now, for various reasons.

Thanks Andy.

But, you are right. It thinks the disc is OK (which I suppose it is!)

It will have written Zones across the disc, so it’s unlikely you’ll be able to get it back.

Unless you have formatted it as a significantly different size from the original, HForm will have overwritten the disc maps in the middle of the drive, irrevocably destroying all the information on where files are, so DiscKnight wont help, apart from saying the new empty drive is fine.

All the files are still on the card, but you would have to search for and reassemble them sector by sector. For things like images there are programs on other platforms (like photorec on Linux) which will automate the recovery of certain file types. But for RISC OS specific files, you are on your own.

This is why we do backups folks.

I have been there (with the old HForm which does not show which drive you are about to format and numbers them differently to SCSIfs) and I received the same advice that the only part of the disc that is overwritten is the disc map and HForm carefully makes sure both copies are overwritten and does not keep a copy of the old map. If the new disc map lives in the same place (somewhere in the middle of the image) as the old map then there is no practical solution for recovery. Only if you happen to choose a very different filecore size or layout is the new map likely to be in a different place and may have left the old map intact.

I have been there (with the old HForm which does not show which drive you are about to format and numbers them differently to SCSIfs)

Me too. It doesn’t help that it asks for a single letter to identify the filesystem, and SDFS and SCSIFS both start with S. I did add some checks that add a final question if the selected disc is either the boot device or the device containing HForm. I don’t know whether they’ve made it to the distributions though.