dillon@CORY.BERKELEY.EDU (Matt Dillon) (03/12/86)
Poo. I'm using double sided, double density (maxell's at the moment): * 5 1/4 floppies were easier to make, and generally did not have anywhere near the density these micro floppies have. * un-polished single sided diskettes will wear-out your drive faster. Those floppies which are polished on both sides usually have the 'single sided' designation when they failed one or more tests on the second surface. I have yet to get a single error on any of my diskettes. ----------------------------------------------------- Q: I cannot seem to disable XON-XOFF (SERF_XDISABLED does not seem to disable it). Has anybody else had this problem? -Matt
rb@ccivax.UUCP (rex ballard) (03/15/86)
If any former Apple ][ or Atari-800 owners remember the old "Flippy Floppy" hack, they might think that "Single Sided" 3 1/2" micro-floppies are ok too. This might be true in some cases but: 1 - Different manufacturers have different standards for "Failing" a 2-sided disk. Some consider one bit error in a double sided disk to be an error. This is usually after several bit patterns are written. Others consider a number of sectors as a percentage of the "overflow track" capacity. Some allow even 50% of one track failure rates. I got that word from a disk salesman when I had a problem with the "flippys". 2 - Because the majority of micro-floppy sales are single sided, some lots may be truly single sided. If one side tests good, the other side isn't even processed (the ferrite on the second side is just a "hedge" in case the first side fails). Minifloppies are usually processed first as highest possible density and sorted down to lower levels as failures occur. In the case of some of the stricter makers, a single sided single density mini-floppy may only have 5 bad sectors as a quad density disk, but that's enough to fail them to single sided If its 3 adjacent on side 2 and 2 adjacent on side one. 3 - In some cases, the lot is downgraded because a certain number of disks "sampled out" and the remaining disks weren't further tested. They may have been intended as 2 sided disks, but then were downgraded. When this is the case, you may have a whole case of good diskettes with only one that is really single sided. In other words, there are pretty good odds that you could find a good manufacturer of double sided disks that are labled as single sided disks, but each disk is a gamble. Maybe the odds are only one in six of having one go bad. Five people will say "they're great", and wonder why that one guy is so paranoid. 6:1 is about the same odds as russian roulette, do you feel lucky :-).