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Old 03 February 2014, 12:05   #7
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Join Date: Aug 2004
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On the subject of PackDev...

PackDev is supposed to support trackdisk sector label data. [In the Amiga trackdisk floppy disk format, each sector has an associated 16-byte "label area". Thus the total amount of data that can be put on a disk using normal trackdisk device commands (not TD_RAWREAD) is (512+16)×1760 = 929280 bytes. Most programs don't use sector label data, and of course it can't be recorded in a normal 901120-byte ADF file.]

On creating a .pkd image file from a floppy disk, the sector label data is supposed to be recorded in the image file. When writing a .pkd file back to floppy disk, you can tell PackDev to write the sector label data by using the ETDFORMAT or TDFLABEL options.

I don't know of any programs which write to the sector label area. So I experimented using PackDev by creating a .pkd image of a formatted floppy disk (AllZeroSectorLabels.pkd). Then I used a hex editor to change some of the sector label data to non-zero bytes, calling the modified file SomeSectorLabelData.pkd. (See from offset $1634 in SomeSectorLabelData.pkd.)

In WinUAE I created an extended ADF file and put that in DF0:. Then I used PackDev to write SomeSectorLabelData.pkd to that disk with ETDFORMAT.

Finally I used PackDev again to create an image file from the just-written-to disk. In theory the new image file should be identical to SomeSectorLabelData.pkd. But in fact the new image file is identical to AllZeroSectorLabels.pkd.

Am I doing something wrong or is PackDev's support for sector label data broken? I don't think it would be a WinUAE problem, unless for some reason WinUAE detects a trackdisk-format track is being written and zeros out all the sector label data???
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