D64 error block handling

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Rakki
Posts: 707
Joined: Fri Jun 03, 2011 8:29 pm
Location: Jyväskylä, Finland

D64 error block handling

Post by Rakki » Sun Jul 03, 2011 6:51 pm

D64 file format error block handling is not implemented on Kryoflux DTC software. Seems that it doesn't mark error blocks at all and as a result disk dumps are "flawless". For sake of clarity and better D64 dumping error blocks handling should be implemented in DTC.

D64 specs:
http://www.unusedino.de/ec64/technical/formats/d64.html

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IFW
Posts: 3077
Joined: Mon Nov 08, 2010 2:42 pm

Re: D64 error block handling

Post by IFW » Sun Jul 03, 2011 8:08 pm

The error map was originally added simply to support (very primitive) protections, and is not very useful otherwise - chances are you don't want a bad disk.
Please use the GUI and you'll have an exact knowledge of the state of the disk.
Alternatively, if you want to use the command line tool, then filter the output to the format analysi using -l8 ('L', output level).
You'll see easily if anything goes wrong. You could redirect the output as well to a file and check that easily with a script or manually.

Grue
Posts: 19
Joined: Tue Jan 04, 2011 7:39 pm

Re: D64 error block handling

Post by Grue » Sun Jul 03, 2011 9:29 pm

I'm sorry to hear this, this renders whole .d64 support completely useless for my purposes. Quite often I do mass transfers of c64 scene disks to as .d64 and I was hoping to use kryoflux for this task in the future.
Errorblock support would be mandatory for kf to be usefull at all on this kind of work.

Maybe someone does 3rd party tool for proper handling of .d64 from streamfiles later, lets hope so :)

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IFW
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Re: D64 error block handling

Post by IFW » Sun Jul 03, 2011 10:35 pm

Er... you CAN see if anything is wrong, more over you can correct it while dumping.
Is there a use-case for purposefully keeping known bad disks, provided a good dump can be achieved?

Grue
Posts: 19
Joined: Tue Jan 04, 2011 7:39 pm

Re: D64 error block handling

Post by Grue » Mon Jul 04, 2011 7:59 am

Example case:

I have currently ~200 floppies from one sceneguy to transfer, some of the disks contain code, bbs databases etc stuff which is well worth of archiving, plus alot of scene releases which may or may not contain something new and usefull. Disks are very rarely labeled at all, or contains something cryptic on the label.

When doing transfers like this, there is very often error as disks are often stored poorly, also they're naturally very old already. As There's endless amount of material involved in transferring scene related disks workload is often shared, someone does the transferring and other people will sort of what's on the disks and extracts useful information.

There's example picture how actual .d64 with error block looks like:

d64lister output picture:
http://sid.fi/~grue/bam_view.jpg

As you can see on the picture there's disk block layout and file list, its quite trivial to see there quickly which files actually contain broken blocks. In this case this is code disk containing some demo routines, and you can see that highlighted file on the right contains broken block, but other files seem to be more or less ok on that floppy. Without this error block you cannot see this at all...

I can understand when archiving original disks with copy protection whole .d64 format is completely useless, but for archiving other stuff its very useful, but in its current form its not very useful as you cannot tell which files are broken on the disk...

I have hundreds of disks waiting for transferring, currently I'm waiting for possibility to dump data from the floppy to single file instead of bunch of stream raw data files, which are pain in the ass to handle.
Also I need way to convert those raw dumps into .d64 files which has this error information in them for later processing. Then its easy later to get back into data mining if someone spots something more important on .d64 which has bad blocks.

I'm currently using tools which involves real c64 drive, but its slow and painful process, I'm hoping to use kryoflux on this :)

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IFW
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Re: D64 error block handling

Post by IFW » Mon Jul 04, 2011 10:20 am

Thanks for the explanation.
D64 error maps will be added to an upcoming DTC release.

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