>by kamiga on 2009/1/13 23:37:57
>Dunno if I count.
>
http://www.techtravels.org/amiga/amigablog>Amiga floppy project blog
>So the normal floppy sync pattern is 0xAAAA 0xAAAA 0×4489 0×4489, but why do we see 0×2AAA ??
>So, 0×2AAA is 0010 1010 1010 1010. right? We’re missing the first bit. It turns out there was a bug in the MFM encoding routine. It was fixed March 16th 1990 at 1:08am in the morning, in revision 32.5 of the trackdisk.device.
It's suppose to be missing the first bit according to my tests with floppy simulation. Supposedly, it allows the heads to sync up properly to beginning of track. Since you have the hardware to analyze these patterns, can you figure out what pattern it reads for high density disk and what speed? Parallel port just not fast enough my machine to analyze the high density disks currently.
