Can anyone explain this bizarre Amiga SCSI HD in WinUAE behaviour?

[mingle]

Hi all,

This is a strange one - bear with me...

I just grabbed an old Quantum LP40S SCSI hard disk (that I once used on my Amiga) and attached it to the SCSI card in my WinXP machine to try out with WinUAE.

It came up fine in XP, but (since I guessed it was still formatted Amiga FFS and I wanted to do a completely fresh Workbench install on it) needed to be partitioned and formatted. So I used the XP disk management util to partition and format it NTFS. I assigned it the drive letter "Z:" and disk label "40MB SCSI" and all worked fine in XP (could copy files, etc).

Then I started WinUAE (the latest version) and added the SCSI harddisk, using the UAE scsi device and kicked off workbench (I 'booted' from the floppy drive into WB3.1 and also had the "Install 3.1" ADF loaded, so I could set up the SCSI HD as a new Amiga drive. I also had the "Add PC drives at startup" option checked in WinUAE.

Imagine my surprise when Workbench appeared showing not only the "40MB SCSI" (NTFS) drive, but also the original "Games 1" disk (which is what the SCSI harddisk used to be - I remembered when I saw it). All of my old WHDload games were still there (35MB of them) and they were still playable!

So how on earth could the Amiga partition/data still be on the drive when I just partitioned and formatted it NTFS?!?

Can anyone explain what happened? :-/

Cheers,

Mike.

[nOw2]

You didn't do a full format.
A quick format only wipes the sections of the disk required for a given file and partition system. Windows and Amiga are different and store data in different positions on the disk so Windows didn't damage the Amiga partition data.

WinUAE is capable of detecting and using real Amiga disks, so that's what it did.

[Piru]

I just grabbed an old Quantum LP40S SCSI hard disk (that I once used on my Amiga) and attached it to the SCSI card in my WinXP machine to try out with WinUAE.

It came up fine in XP, but (since I guessed it was still formatted Amiga FFS and I wanted to do a completely fresh Workbench install on it) needed to be partitioned and formatted. So I used the XP disk management util to partition and format it NTFS. I assigned it the drive letter "Z:" and disk label "40MB SCSI" and all worked fine in XP (could copy files, etc).

Why did you do that?

Wouldn't it be smarter to use the HDD in the XP system itself? It surely is faster.

[Thomas]

The Amiga's RDB can live anywhere in the first 16 blocks of the HDD. So if your Amiga partitioning software wrote the RDB to a later place, it hasn't been overwritten by the PC's MBR which always resides in block 0.

When formatting with NTFS you probably did a quick format which only writes a new directory and does not wipe all data on the HDD. Additionally the Amiga's FFS starts creating files in the middle of the partition while NTFS starts at the beginning.

All this means that both NTFS and FFS can coexist on the same HDD. However, some of your Amiga files probably got corrupted by the NTFS attempt.

I wonder why you did this disk management / NTFS thing at all when you want to use the HDD for the Amiga. It's the most stupid thing to do IMHO. WinUAE will refuse to use the HDD if there are PC partitions on it.

Bye,
Thomas

[mingle]

I know it sounded a bit silly...

The reason I formatted it in XP was to ensure there were no bad sectors/blocks before using it in WinUAE. I actually forgot that it was already formatted AMiga FFS - since it'd been sitting in the cupboard for so many years!

I initially thought it was formatted MacOS (since it came from an old Mac Classic). So I thought it'd be a good idea to use XP to partition and test the drive before using it in WinUAE... I was planning on blowing away the NTFS partition after I'd confirmed the disk was good and doing a clean WB3.1 install from within WinUAE...

I actually did a full format, rather than a quick format, which is why I thought it was very weird that my Amiga FFS partition survived at all...

Thomas's explanation seems to have put my mind at rest! :-)

Thanks for all the info guys...

Cheers,

Mike.

[Zac67]

It's not a first-class idea to format and partition one and the same drive on two systems simultaneously. Since they don't know of each other (there's no way they could), chances are that each happily overwrites the others data. Delete all partitions on one side before seriously using it with the other.

Windows (up to XP afaik) format doesn't clear the drive on full format, it only scans for defects.