Path: utzoo!utgpu!water!watmath!clyde!ima!cfisun!lakart!dg From: dg@lakart.UUCP (David Goodenough) Newsgroups: comp.sys.cbm Subject: Woodpeckers inside 1541 drives Message-ID: <168@lakart.UUCP> Date: 23 Jun 88 13:12:26 GMT References: <935@flatline.UUCP> Organization: Lake - The systems people Lines: 26 From article <935@flatline.UUCP>, by erict@flatline.UUCP (j eric townsend): > In article <565@mannix.iros1.UUCP>, desmarai@iros13.iro.umontreal.ca (Stephane Desmarais) writes: > >> (Why didn't they find a way do avoid doing more than one or two bump on >> the head stop?) > > > It has to do with the way the head resets to track 0. Instead of making > a "where is the head now" sensor, they used GCR encoding. The drive > reads the GCR encoding data off of the disk, and can figure out > where it is. So how does it decide a reference point? Bring the > head in towards track zero for X amount of time, where X > amount of > time for the head to go all the way across from track 40 to track 0. I don't know if they are available in North America, but my father recently visited me from England, where he also has a C64 w/ a 1541. Apparently there is a widget known as an "Anti-woodpecker" spring that you can put in your 1541 to quieten up the self destruction when it is banging the head against the head stop. I'm getting him to send me one, so that my 1541 shuts up. (I've altered the Dist to include England - Comments anyone over there?) -- dg@lakart.UUCP - David Goodenough +---+ | +-+-+ ....... !harvard!cca!lakart!dg +-+-+ | +---+