Amiga Floppy Drive Research – Part 16

Tool building is the order of the evening.  The MFM decoder now can scan all of my Logic captures and save ADF files of the same name, along with the MD5 hash.  See the example output:

093d5091d5ce7e3fd430d49c75b4e553 *AutoDocsDisk1of5.adf
9d00a6f3960292d759d5323b66d6231a *AutoDocsDisk2of5.adf
G:\AutoDocsDisk2of5Copy.bin - missing block(s): 655 825
3e6d092cc04f10af29fe328e42fbd891 *AutoDocsDisk2of5CopyOfCopy.adf
2ec2fbf190c22ef88d90ffdeb4b728a7 *AutoDocsDisk3of5.adf
838cc5dbbbc9b60bc2fdccb67a3dde5e *AutoDocsDisk4of5.adf
a48289feea65b15b014e272b231bc8cd *AutoDocsDisk5of5.adf
1a14f7737e21357542781c28fbd74f74 *XDCC1.adf
bb4b789bd96f560f324f5036b72c1f6c *XDCC2.adf
37c16da9ca389d88b58605255cddad31 *XDCC3.adf
203a6f1518a315a82f414ee6547fba25 *XDCC4.adf

Also see the extra logging, it now shows what blocks could not be recovered from the capture.

The most useful MD5 hashing tool for the Amiga in the end turned out the be this one http://aminet.net/package/util/crypt/MD5SUM.  There was an md5sum2 program that supported Amiga wildcards etc, but this turned out to lock up the machine.  No source code supplied so I could not fix it.

Here is a summary of what everything looks like:

 match			093d5091d5ce7e3fd430d49c75b4e553 *AutoDocsDisk1of5.adf
no read on amiga	9d00a6f3960292d759d5323b66d6231a *AutoDocsDisk2of5.adf
no read on PC		3e6d092cc04f10af29fe328e42fbd891 *AutoDocsDisk2of5Copy.adf
match			3e6d092cc04f10af29fe328e42fbd891 *AutoDocsDisk2of5CopyOfCopy.adf
match			2ec2fbf190c22ef88d90ffdeb4b728a7 *AutoDocsDisk3of5.adf
match			838cc5dbbbc9b60bc2fdccb67a3dde5e *AutoDocsDisk4of5.adf
match			a48289feea65b15b014e272b231bc8cd *AutoDocsDisk5of5.adf
match			1a14f7737e21357542781c28fbd74f74 *XDCC1.adf
match			bb4b789bd96f560f324f5036b72c1f6c *XDCC2.adf
match			37c16da9ca389d88b58605255cddad31 *XDCC3.adf
match			203a6f1518a315a82f414ee6547fba25 *XDCC4.adf

So, you can see we actually do have a problem disk:  AutoDocsDisk2of5Copy.  When I bought these disks from Commodore disk 2 proved to be a problem disk and I eventually was able to copy the files from it, which is why there is a copy in my collection.  I decided to make a fresh copy like I did before earlier in my floppy studies.  This was a bit of a problem since AmigaDOS changes the sector/sectors remaing number (i.e. the copied disc may not be a 100% match to the original).  In the end I solved this problem by using XCopyPro in nibble mode.  As before the newly written disk is readable on the PC.

The next session then is to study blocks 655 and 825 on the PC to see what the problem might be.  At least now if I change the code in any way I can easily run the new logic over the 11 captures to make sure I don’t break something in the process…

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