Gregory Weston wrote:
In article <1180985715.571490.169590@n4g2000hsb.googlegroups.com>, heuser.marcus@freenet.de wrote:On Jun 4, 8:31 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:In practice, "flippy" disks are just as reliable as single-direction disks. People made up lots of reasons about why this wouldn't work, but except for the truly rare case of *single-sided* media, there was never any actual evidence, since they work perfectly. The rule for Apple 5.25" disks is "if it formats, it works"--and works for a very long time. Appleworks was distributed as a "flippy", as were most applications as it became clear that there was no downside (except being able to access only one side at a time--but you could always copy the back to another disk if you needed that).I read somewhere that the manufacturer of the disk always coated both sides of the disk in equal quality because at this stage of the production process it couldn't be determined how the disk was later inserted into its jacket.What I recall hearing is that single-sided disks were double-sided disks that had (at least potentially) failed testing on the bottom. Which was the side that the Disk ][ drive used.I suspect that as manufacturing processes improved they would just have started filling the boxes with whatever they had, but telling you you were SOL if a disk labeled single-sided did fail on the back.
That was probably true for about six months at the beginning of diskette manufacture. Once the process was stable, both sides worked equally well, even if only one was "certified". Apple's usage of the medium is actually more tolerant of micro-defects than MFM in any case (not that that was an issue in the early days). -michael NadaNet file server for Apple II computers! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."