Path: utzoo!attcan!uunet!super!udel!rochester!cornell!uw-beaver!tektronix!tekcrl!tekfdi!videovax!stever From: stever@videovax.Tek.COM (Steven E. Rice, P.E.) Newsgroups: comp.sys.amiga.tech Subject: Re: Request to Commodore (Bad Blocks) Keywords: trackdisk.device Message-ID: <5234@videovax.Tek.COM> Date: 28 Sep 88 19:16:46 GMT References: <8891@cup.portal.com> <5660018@hpcvca.HP.COM> <40244@linus.UUCP> Reply-To: stever@videovax.Tek.COM (Steven E. Rice, P.E.) Organization: Tektronix Television Systems, Beaverton, Oregon Lines: 24 In article <40244@linus.UUCP>, Robert I. Eachus (eachus@mitre-bedford.arpa) was commenting on a suggestion to begin floppy disk writes at the index hole when he wrote: > . . . Right now, trackdisk.device must rewrite an entire track even if > only one sector is changed, and more important must read a track > completely to write one sector. If a "smart" trackdisk.device knows > where sectors are located, it can do single sector writes in an > average of 0.7 rotations, instead of 2.2. . . . Nope. In order to get 880K bytes on a disk (instead of 720K), trackdisk writes 11 sectors in succession, *without* the intersector gaps that are found in the "normal" (i.e., 720K) format. Attempting to write a single sector would result in trashing the end of the previous sector or the beginning of the next, depending on the relative timing of the write to that of the previous ones. Thus, it is still necessary to both read and write a track at a time. Steve Rice ----------------------------------------------------------------------------- * Every knee shall bow, and every tongue confess that Jesus Christ is Lord! * new: stever@videovax.tv.Tek.com [phone (503) 627-1320] old: {decvax | hplabs | uunet | uw-beaver}!tektronix!videovax!stever