Conference hydra::amiga_v1

    They certainly can be used, but you run the risk that the unverified
    side (the "other" side) won't work.  It's not clear whether
    manufacturers just don't verify one side or verify both and sell
    the ones that only verify on one side as single sided.
    
    At about $3 a disk, your "$10 to $20 cheaper" must mean in some
    quantity.  Dozen?  Case?
    
    len.
    

    You're probably better off buying bulk diskettes. Computer Shopper
    magazine has trillions of ads for cheap bulk disks, most of them
    warrantied. I bought 100 DS 3.5" disks for $200 or so, and resold
    almost half. Problem with the ones I bought is they came without
    labels, but that was my mistake. You can get them with labels for
    not much more. I probably will be needing some more sometime soon,
    since I'm running out, if anyone is interested send me a note to
    KAHLUA::SANTIAGO and we can split an order.
    

Buying single-side disks for double-sided use is a mistake.  Most
manufacturers that sell both single- and double-sided disks only
have one manufacturing process.  Those disks that fail verification
on only one side go on to become single-sided disks.  If there is a
shortage of single-sided disks after this, then some of the blanks
are tested ON ONE SIDE ONLY to fill out the required number of
single-sided disks.  The manufacturer only does as much as he has
to.  So either the second side is bad, or untested.  I wouldn't
trust my data to that even if the disks were free.

    Copy that pd software all the time has put me into contact with
    a fair number of different brands of disks.  Every once in a while,
    I run into one that just won't copy, or it won't format.  In all
    but one instance, the disk in question was only certified for single
    sided operation.
    
    And, when some of these things fail, they fail sort of quietly.
    That is, you might be able to format ok, and even write to them
    ok, but after a while, you'll notice files have bad blocks appear
    in the middle of them.  By then, it's too late if you don't have
    a backup.
    
    I wouldn't bother with SS disks.

    Perhaps 5.25 inch floppies act differently than the 3.5 inch disks
    on the Amiga but I have 50-60 single sided double density floppies
    that I use on an IBM PC with double sided disk drives and have had
    no problems.  I have used BASF, Datalife, disks bought from IBM,
    as well as some generic brand.  Only once have I had a disk failure
    and after reformatting the disk I used it again and have never had
    trouble with it since.  I have had the PC for 3 years without problems
    so maybe I'm just lucky.  However, I have friends who also use single
    sided disks on both sides without problems.  One roommate even used
    both sides of the disk on an Apple II by cutting a matching write
    protect notch in the disk and flipping it over to use the other
    side.  I don't think I would recommend that but I see no reason
    not to use both sides in a double sided disk drive.
    One final note:  I have never used Maxell disks but I have been
    told they do not format well on both sides.
    
    					John

    re: -1
    
    Perhaps the reason why the 5.25 floppies work is that the surface
    area is larger.  The surface area of a 3.5 disk is much smaller,
    and much more sensitive to damage (that's why it's in a hard plastic
    shell).  The protection of the hard plastic shell is one reason
    why 3.5 disks frequently hold more data than the larger disks.
    
    I have had a few problems with SS/DD disks.  They formatted fine.
    They verified fine.  Later, data was lost.
    
    Not worth the risk.
    
    Randy
    

    RE: -2
    
    I also suspect that the difference between 5.25 and 3.25 SS/DD disks
    is one of economy. That is, since most of the 5.25 disks (due to
    the IBM PCs & look-a-likes) are destined to be used in DS/DD manner,
    the manufacturing process must be improved to the point that most
    of the disks will pass the double sided test. Those that fail (few)
    and those that are reduced to SS (and not tested for DS) are sold
    as double sided.
    
    However, in the 3.5 world, until recently only the Mac was a serious
    user of 3.5 inch disks. It only required SS. Guess what... Most
    of the manufacturers did not need to insure DS ability, since there
    was no market for it, so....
    
    Moral of the story, since DS 3.5 inch disk demands are growing,
    there will be a point when SS disks will work reliably. But NOT
    right now... 2 or 3 years max.

    I have used Maxell DS/DD disks exclusively since I bought my Amiga
    last October, and have never had a Read/Write error. Not only can
    the other side of SS/DD disks not be verified, they also might not be
    "burnished", which polishes the surface of the disk. This could
    cause excessive disk head wear.
    
    An advertiser is the latest issue of BYTE was selling Maxell DS/DD
    for $22.95 per box of 10. The prices have been dropping fast. Last
    fall, the average mailorder price was around $39.
    
    -Jeff
    

    I own an Atari ST, not an Amiga, but this is certainly relevant
    to this discussion.  I've always used certified DS/DD 3.5" disks
    and not had any problems.  But a while back, a friend of mine, also
    with an ST, decided not to listen to any warnings and store all
    his stuff on SS disks.  Well, they worked OK at first, but later
    on he began having all sorts of troubles.  I believe the final count
    when he finally gave in and copied everything to certified DS disks
    was 4 disks blown out of 11.  The key point is that none of them
    showed any problems initially, it was only after some use that things
    started going bad.   So, I can say from (second-hand) experience,
    don't use SS disks.  Pay the extra $10 and get certified DS.  --Mike

    
    
    Would anyone here put bald tires on the back of a car, and Pirellie's
    (sp?) on the front?
    
    brian
    

Hi

I don't own an Amiga and despise Commodore, but am looking in here 
for the first time to learn about the higher end Amigas because
it might be what I am looking for in the distant future to augment
my Atari ST in my MIDI set-up.

Now to the topic.  In the 2+ years since this topic was started I would
like to hear peoples experiences now using SSDD disks.  The reason I ask
is because I have heard from a friend in Utah that the ST, I*M 3.5", and
AMIGA drives use the back side of the disk while the MAC uses the top of
the disk in its SS drives/writing.  That would mean that a manufacturer
would have to certify both sides to ensure that it could be used in any machine,
top or bottom of disk, because he doesn't know what mchine it is being used
on.  Anybody know anything about this???

CHad

    re .11	With DS/DD 3.5 disks going for $0.85 a piece in quantities
    of 25, why bother ?
    
    	R	
    

Because I want to know if such a thing is true, not because I need
to buy SSDD disks.  Thats why.

Chad

    The amiga is an 880K disk drive and uses both sides of the disk
    as does the ibm 720K disk drive.
    
    - steve

Re: .11

I suspect your friend doesn't know what he's talking about.

The Amiga only comes with double sided drives, and always has.

All of the current IBM 3.5 inch drives are double sided.  I don't know
if anyone ever attached old single sided 3.5 inch drives to a clone.  If
so, I suspect that that configuration was not very popular.

I don't know what sides of disks are read by single sided ST or MAC drives.
You can be that if they differ, that disks are manufactured to be compatible
with the Mac (the first, and for a long time, the only consumer of 3.5 inch
drives).

I have heard claims that different single sided 5.25 inch disk drives
read different sides of the floppy, but I haven't heard it about this
about 3.5 inch drives.  I almost suspect that your friend is just
recirculating an updated version of this story.

I occasionally run into someone who says that 3.5 inch disk drives are
unreliable, and that disks go bad frequently.  Usually when I inquire
about the brand of disks they use, I discover that they either use
disks without a brand name from an unknown manufacturer, or that they
are using single sided disks in a double sided drive (or both).

Their probably are some brands of single sided disks that work well in
double sided drives.  There are also some brands that will be junk when
you try the same trick.

I always buy double sided Sonys.  Out of 400 disks in two+ years, I've
only had three bad ones.

    I bought a box of Maxell SS disks by accident once for some stuff I
    was sending my brother.  I wrote the whole box before I noticed my
    mistake.  I couldn't take them back to the store after doing that, so
    I gave them to my brother as they were and told him to return any he
    had problems with.  Four of the disks had errors.  Since we exchange 
    disks frequently and this is the only time we've had a media problem, 
    I assume it was due to the disks.

    - Cliff