Supercard vs Kryoflux

[JimDrew]

Yeah, since Keir (disk Utils) and Jeff (HxC) have done such a great job with the SuperCard Pro support, I really haven't had to do anything. However, I will be releasing a new version of firmware in the near future that adds support for the SD card socket and built-in commands for imaging tracks and/or disks using the SuperCard Pro without the USB port. I will be releasing code/schematics for making a simple Arduino controller with a LCD screen and push buttons that will control the SuperCard Pro (through one of its serial ports) so you can make a simple copy station with a single or dual drives. With dual drives you can do a drive to drive copy with verify, and a single drive can do .ADF to disk in 2 passes, or .d64/.g64 in a single pass. I might add other formats (like .atx for Atari ST, or .dsk for IBM PC).

[NLS]

Thanks for the update Jim.
Hope to find an (easy and cheap) way to get this in Greece.

[Vipersan]

I love to dump and preserve floppy software regardless of format or origin..
I have both units ...most recently the SCP ..
both boards are now mounted in cases with 5.25" and 3.5 inch drives.
How to compare them ..??
Both have their uses and quirks.
I tend to use Kryo for intensive floppy interrugation ( poor flux density ) and have had much success though never 100%
I prefer to use Kryo for dumping PC based floppies simply because of the ability to dump direct to IMG.
That said SCP excells when used with Amiga disks and has the ability to archive copy protected Amiga floppies...and although the Kryo board can also dump exact flux images ..the process is somewhat complicated as images of protected software are not easily restored to physical media.
SCP on the otherhand does not have such problems.
Which would I choose to lose if I had to make a choice.
Kryo and keep SCP...
Jims board is superb ...easy to use..and Jim is so very helpful.
Not that I want to part with either...but for ease of archiving ..SCP gets my vote.
rgds
VS

[AmigaHope]

Someone needs to write a tool that combines multiple flux reads to get a good "average" on weak bits, and then tries to brute force repair bad sectors by trying all values for the weak bits until it matches the CRC. If less than 32 bits of the sector are bad then collisions should be low, and even if it's a few more you could take all the collisions and analyze the various versions of the file to find the "right" solution (depending on if the file is graphics, audio, code, text, etc. and you have like 8 different collisions, only one of them will probably seem "right". Especially on code.)

[demolition]

The point with weak bits is that there is no 'right' value. If you want to write a working copy of a disk containing weak bits, you need to recreate those weak bits on the copy. When the code tries to read those weak bits, it expects to read different values and if the value is constant, no matter what it is, it knows that it is a copy.

[JimDrew]

That is correct - weak bits deliberately change data, often used for copy protection.

SuperCard Pro has the ability to extract good data from bad flux with a few different disk formats, namely Amiga and now C64. The flux bitcell "window" is typically about +/- 5% with PAULA's data separator on the Amiga. With SuperCard Pro it uses a +/-48% window, which is a much broader range to try to use for recovering data from bad sectors. You can also set the number of "retries" so multiple reads are also used.

[Magic]

Thank you for this thread. I also own both the Kryo and SCP. I am still learning to use both of them and I appreciate this valuable information. Thank you Jim for all of your help as well.

[chip]

Which is the best between these two if we are talking of "NOT protected" disks ?

[demolition]

I think that for simply reading plain DOS disks, the differences are minor. Whether one or the other is 'best' probably comes down to which UI you like the best.

[chip]

Thanks for reply demolition

[AmigaHope]

Originally Posted by demolition

The point with weak bits is that there is no 'right' value. If you want to write a working copy of a disk containing weak bits, you need to recreate those weak bits on the copy. When the code tries to read those weak bits, it expects to read different values and if the value is constant, no matter what it is, it knows that it is a copy.

I don't mean weak bits for copy protection purposes, I mean bits from a normal disk that have become weak due to rot. i.e. there WAS a "right" value once upon a time but it is now difficult to read. Thanks to the CRC, however, we can brute force values to determine what the right value is, as long as we haven't lost enough bits for there to be collisions -- and even if there are collisions, there may be few enough of them that we can manually check the files to see which of the solutions to the CRC matches up best with what we expect.

[vbgd]

The Kryo team has had ideas of an verify regarding non standard tracks.