Zitat von Wolfgang Moser <email@example.com>: > Hello Pete, > > Pete Rittwage schrieb: > > Hi guys, > > > > With the help of "TeaRex" on my forum, I added a simple way to > > read/write disk images using the index hole sensor built into the 1571. > > Through this addition, a revelation occurred. > > > > We had always assumed (since the 80's) that the Electronic Arts' "fat > > tracks" protection had 2 tracks (34 and 35) perfectly aligned. I added > > the index hole code and wrote out the disk perfectly aligned to track 0 > > and thought it was beaten. :) > > > > Well, it turns out this assumption is *not* true. When reading against > > the index hole, track 35 is actually skewed back 1/4 track or so on all > > the original disks. If I write it back out skewed in this way, it > > boots. These were never "FAT" tracks at all, just a specific track skew > > between two identical copies of a track. That makes perfectly sense, since the time to move the stepper from Track34 to Track35 is about the same time as you need to read 1/4 of a track. ---------------------------------- Ein Service von http://www.news.at Message was sent through the cbm-hackers mailing listReceived on 2013-04-03 14:00:04
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