Preserving Disks with Mismatched Sectors

All questions about how to use KryoFlux go here.
Post Reply
FrozoGrabbins
Posts: 5
Joined: Tue Jan 26, 2021 10:10 pm

Preserving Disks with Mismatched Sectors

Post by FrozoGrabbins »

Greetings!

I have had some problems with some of my earlier 3.5" disks I'm trying to image and I'm hoping someone here can help. The first track seems to read correctly but after that the rest of the 40 tracks come up yellow with an "N" and the warning of sector found but not in image. I am using the GUI since I'm new and the command line interface has me a little intimidated. I am reading it with raw preservation preset as well as MFM sector disk. I can post the contents of both if this will be helpful to someone.

Another oddity is that the diskettes images created are 320k .img files which i wouldn't expect, so i guess i have some settings wrong somewhere. Thanks for any help you can provide!
MSFS Kryoflux.JPG
brightcaster
Posts: 352
Joined: Fri Nov 08, 2013 10:48 pm

Re: Preserving Disks with Mismatched Sectors

Post by brightcaster »

From the name you've given to the image file I guess you are trying to dump an early version of Flightsimulator. I remember that Flightsim II came on a 5.25" floppy where only the first track was in standard format to boot the disk from bios. The other tracks have been treated by a custom loader. I don't know if that is the same with later versions on 3.5" floppies.

The bottom line of the GUI gives a hint to what the problem is. The sectors on the yellow tracks have a different sector size. Maybe its 1024 byte (5 sectors for DD or 10 sectors for HD per track) to get more data onto the floppy (because of less sector gaps).

A raw dump would be really helpful to examine the content of the mismatched tracks...

David
FrozoGrabbins
Posts: 5
Joined: Tue Jan 26, 2021 10:10 pm

Re: Preserving Disks with Mismatched Sectors

Post by FrozoGrabbins »

Yes that is correct. I am trying to preserve disks for early MSFS. I have uploaded to my dropbox, link below. It was my understanding that this version was not a pc booter and could be used to install on a HDD. So I was hoping to get a working disk image to use through dosbox. I guess if its working with non standard sector sizes that might not be possible? Thanks for your help!
MSFS Kryoflux.JPG
https://www.dropbox.com/s/ibp4r4ruqi44s ... 4.zip?dl=0
brightcaster
Posts: 352
Joined: Fri Nov 08, 2013 10:48 pm

Re: Preserving Disks with Mismatched Sectors

Post by brightcaster »

Are you sure that this is a 3.5" floppy image? It rather looks as 5.25" with 40 tracks single sided, and (as I described) the first track is 8 sectors with 512 and the other tracks are 5 sectors 1024 byte each!

This geometry can't be dumped to a img file properly as this doesn't provide information about the exact geometry but only the sector content. You may use the HxCTool to export the kryoflux raw stream to an imd file (Dave Dunfields image tool file format). This can be loaded to different emulators...

https://hxc2001.com/download/floppy_dri ... rmware.zip

David
ZrX
Posts: 642
Joined: Tue Dec 06, 2011 9:09 pm

Re: Preserving Disks with Mismatched Sectors

Post by ZrX »

Clearly a 3.5" disk but just first 40 tracks on side 0 used, the rest of the disk (and side 1) is unformatted.

As said, the mixed sector sizes makes typical img diskimage file unusable with this title. The conversion tools on PCE could possibly convert this to a image that can be played on PCE.
FrozoGrabbins
Posts: 5
Joined: Tue Jan 26, 2021 10:10 pm

Re: Preserving Disks with Mismatched Sectors

Post by FrozoGrabbins »

Your conclusions appear to be correct about the sector size. I reran the program but forced the sector size to be 1024 and I got this result which shows tracks 2-39 as good and only track 1 as mismatched now. Also the new disk image size is 400KB.
MSFS Kryoflux.JPG
This is definitely from the 3.5" disk shown above because i've been having some trouble with my 5.25" drive I usually use. I imaged both the same result. So does the raw dump look good and readable then?
FrozoGrabbins
Posts: 5
Joined: Tue Jan 26, 2021 10:10 pm

Re: Preserving Disks with Mismatched Sectors

Post by FrozoGrabbins »

ZrX wrote: Sun Feb 07, 2021 5:50 pm Clearly a 3.5" disk but just first 40 tracks on side 0 used, the rest of the disk (and side 1) is unformatted.

As said, the mixed sector sizes makes typical img diskimage file unusable with this title. The conversion tools on PCE could possibly convert this to a image that can be played on PCE.
Where does one get these conversion tools?
brightcaster
Posts: 352
Joined: Fri Nov 08, 2013 10:48 pm

Re: Preserving Disks with Mismatched Sectors

Post by brightcaster »

Yes, the dumps look perfect, but the correct size is far from 400k! You have to change "side mode" to "side 0" also in the gui settings!

The correct size would be 203776 byte (8*512+39*5*1024)...

David
brightcaster
Posts: 352
Joined: Fri Nov 08, 2013 10:48 pm

Re: Preserving Disks with Mismatched Sectors

Post by brightcaster »

The tools are in the bin folder of the package...

http://www.hampa.ch/pce/download.html

David
FrozoGrabbins
Posts: 5
Joined: Tue Jan 26, 2021 10:10 pm

Re: Preserving Disks with Mismatched Sectors

Post by FrozoGrabbins »

brightcaster wrote: Sun Feb 07, 2021 6:16 pm Yes, the dumps look perfect, but the correct size is far from 400k! You have to change "side mode" to "side 0" also in the gui settings!

The correct size would be 203776 byte (8*512+39*5*1024)...

David
Thanks David,

I revised the settings in the GUI and I still got a similar result, a disk image that is 400kb.

I guess I can't trust the disk image like was previously stated since its not a usable image. I'll have to look at the tools and try and convert it to a usable file for PCE.
MSFS Kryoflux-.JPG
MSFS Kryoflux-1.JPG
MSFS Kryoflux.JPG
Post Reply