chad@byuvax.bitnet (04/17/88)
Question: Is it true that MACs use the top of the disk while Atari/IBM use the undersides? If that is true, then all SSDD disks are *certified* DSDD disks as the manufacturers wouldn't know which computer is going to be used and therefore which side to certify... That is what I have heard. If it is true, then it is the biggest scam around. Chad CHAD@BYUVAX.BITNET
cmcmanis%pepper@Sun.COM (Chuck McManis) (04/22/88)
In article <184chad@byuvax.bitnet> chad@byuvax.bitnet writes: >Question: Is it true that MACs use the top of the disk while Atari/IBM >use the undersides? No. Both use the same side. Sometimes bogus disk salespersons will lie to you and say that DSDD disks and SSDD disks are exactly the same to make a sale but they aren't. The disk manufacturing process goes something like this : (I toured Dysan/Xidex once ...) o A sheet of mylar is coated on both sides with their own custom oxide. o It is cut into little circles. o The circles are buffed to near flat on *one* side. o Disks are tested for R/W errors, ones that fail are recycled o Some of the ones that pass get packaged as SS disks. o The rest get burnished on the *other* side and tested again. o The ones that fail get recycled (humans can't tell which side failed) The ones that pass become DSDD disks. >That is what I have heard. If it is true, then it is the biggest scam >around. There *is* oxide on both sides of the disk and they are processed to be DSDD disks, even though some get pulled early in the process. The problem is that on 3.5" disks, where one is storing 135 Tracks/Inch, it is a *lot* easier to get defects. (As opposed to 5.25" disks at 40 TPI). What does it mean to you? It means 1) Some percentage of that disks you buy that are labeled SS can be recorded on the uncertified side. (This will be higher than on similar lots of 5.25" disks. Based on the tour I would guess it to be about 10% (5 out of 50)) 2) These disks will *always* cause excessive head wear on the disk head on the 'wrong' side because they are not burnished. 3) The may not be capable of retaining data reliably on the wrong side. I don't know where you buy disks but I find that bulk disk usually go for $1.00 ea for SS and $1.20 ea for DS. If you lose 5% because they can't be formatted then you are actually paying $1.00/.95% good = 1.05 each. Or saving about 15 cents per disk. The risks you are incurring are early death of your disk drive because one head is reading an unburnished disk and being sanded to nothingness, and having a backup go bad 'in the can' because the oxide on the other side didn't have the retention power it would have required to be certified. It's not worth it to me, but I am not you. You be the judge. --Chuck McManis uucp: {anywhere}!sun!cmcmanis BIX: cmcmanis ARPAnet: cmcmanis@sun.com These opinions are my own and no one elses, but you knew that didn't you.
braner@batcomputer.tn.cornell.edu (braner) (04/23/88)
[] IS it really true (as claimed by Chuck McManis) that SS disks are "burnished" (polished?) on one side only and that the other side physically wears down your drive's head? That would mean that SS disks (including the original disks of almost all commercial SW for the ST!) are a bad idea in a DS drive, EVEN IF ONLY ONE SIDE IS USED! I personally cannot see a difference in smoothness between the sides, but you might need a microscope... - Moshe Braner SS drives are OBSOLETE
wes@obie.UUCP (Barnacle Wes) (04/24/88)
In article <184chad@byuvax.bitnet>, chad@byuvax.bitnet writes:
% Question: Is it true that MACs use the top of the disk while Atari/IBM
% use the undersides? If that is true, then all SSDD disks are *certified*
% DSDD disks as the manufacturers wouldn't know which computer is going
% to be used and therefore which side to certify...
% That is what I have heard. If it is true, then it is the biggest scam
% around.
Nope. The single-sided 3.5" disk drives write on the top. The O.S.
has nothing to do with this. A 3.5" SS disk drive is undefined in the
MS-DOS world, by the way - MS-DOS only recognizes 720K and 1.44M 3.5"
disks.
--
/\ - "Against Stupidity, - {backbones}!
/\/\ . /\ - The Gods Themselves - utah-cs!uplherc!
/ \/ \/\/ \ - Contend in Vain." - sp7040!obie!
/ U i n T e c h \ - Schiller - weswes@obie.UUCP (Barnacle Wes) (04/25/88)
In article <50424@sun.uucp>, cmcmanis%pepper@Sun.COM (Chuck McManis) writes: > The disk manufacturing process goes something like this : > (I toured Dysan/Xidex once ...) Hah! You were spoiled! Dysan is truly the BEST manufacturer of floppy disks around. Their manufacturing procedure differs from the rest of the floppy disk world in one important area: Dysan cuts the mylar base into donuts and then applies the magnetic oxide coating in circular tracks and buffs the disk surfaces. Everyone else lays on the oxide coating and buffs the disk in a cross-hatch matrix BEFORE cutting the donuts. It's a small difference, but Dysan has the best warranty on disks I've ever seen, so they must be pretty sure of their process. BTW, this was explained to me by a factory rep from Syncom (a disk manufacturer) about 6 years ago, when I worked in a computer store in Salt Lake City. We sold Syncom, Maxell, and Dysan disks. We never had a Dysan come back, we would replace a Maxell every couple of months, and the Syncoms worked great in Apple ][s and not at all in anything else. The Maxells sometimes had troubles when we tried to format them on the DEC Rainbow, which had pretty picky floppy drives. DEC sold Dysans with their label on them, so we sold Dysans to the Rainbow and Pro-350 owners. -- /\ - "Against Stupidity, - {backbones}! /\/\ . /\ - The Gods Themselves - utah-cs!uplherc! / \/ \/\/ \ - Contend in Vain." - sp7040!obie! / U i n T e c h \ - Schiller - wes
ron@argus.UUCP (Ron DeBlock) (04/25/88)
Just a note in this debate: I've used literally HUNDREDS of SS disks as DS disks, both 5.25 and 3.5. I've done this for years (about 5 years). I have had exactly 3 disks go bad. For two of them, they wouldn't format. For the third (the only bad 3.5), it went bad after a couple of hours. I should have known better than to use it, as it made funny squeaking/squealing noises as it turned. -- Ron DeBlock KA2IKT 213 River Dr. ...!rutgers!galaxy!argus Lk Hiawatha, NJ 07034 ron@wilbur.njit.edu (201) 316-6807 "Oooo...that's mean!" "No, just average."
rich@lakesys.UUCP (Rich Dankert) (04/26/88)
>Nope. The single-sided 3.5" disk drives write on the top. The O.S. >has nothing to do with this. A 3.5" SS disk drive is undefined in the >MS-DOS world, by the way - MS-DOS only recognizes 720K and 1.44M 3.5" >disks. >-- > /\ - "Against Stupidity, - {backbones}! > /\/\ . /\ - The Gods Themselves - utah-cs!uplherc! > / \/ \/\/ \ - Contend in Vain." - sp7040!obie! > / U i n T e c h \ - Schiller - wes Wrong. MS-DOS will work with 360K SS disks also. All one hase to do is change the information in the config.sys file and one can make MS-DOS work with SS drives, a 5 1/4 and a SS drive or DS drive and a SS drive or any combination of the above. One must remember that since your working with a SS drive (3 1/5) that you may\will have to have some of the utilities on a seperate disk. I do tis, and place the most un-used programs on the second disk, therefore aleveatng the gruesom problem of disk swappng. rich..... UUCP: {Ihnp4,uwvax}!uwmcsd1!lakesys!rich -- Disclaimer: The words, expressions posted here are my own..... Nothing is ever so bad that it can't be made worse by trying to fix it -- Law of the Hacker
tainter@ihlpg.ATT.COM (Tainter) (04/26/88)
In article <167@obie.UUCP>, wes@obie.UUCP (Barnacle Wes) writes: > Nope. The single-sided 3.5" disk drives write on the top. The O.S. > has nothing to do with this. A 3.5" SS disk drive is undefined in the > MS-DOS world, by the way - MS-DOS only recognizes 720K and 1.44M 3.5" > disks. Actually, PC-DOS will recognize them but it will not format them for you. I transfered between my folks PS/2 and my Atari with an SS drive without problem one. --j.a.tainter
sjl@eagle.ukc.ac.uk (S.J.Leviseur) (04/27/88)
In article <172@obie.UUCP> wes@obie.UUCP (Barnacle Wes) writes: >In article <50424@sun.uucp>, cmcmanis%pepper@Sun.COM (Chuck McManis) writes: >> The disk manufacturing process goes something like this : >> (I toured Dysan/Xidex once ...) > >Hah! You were spoiled! Dysan is truly the BEST manufacturer of >floppy disks around. Their manufacturing procedure differs from the I remember getting 11 bad disks out of a batch of 400 once. There may have been more duff disks, we didn't bother to go through the lot it didn't seem worth while. By bad I mean they failed to format of three different machines, and when we they were sent back to the UK distributor they checked them and agreed the disks were faulty. It still took a solicitors letter to get a refund. I was less than impressed and never have anything to do with Dysan if I can help it. There is/was a rumour that Dysan disks in Europe are largely made by Rhone Poulac (well the name is almost right). Whether or not this is true I don't know, but it might explain differences between the USA and Europe. sean
manis@faculty.cs.ubc.ca (Vince Manis) (04/28/88)
I'm most definitely not an expert on disks. What I do know is that disk quality
seems to be highly variable. If you're as ignorant as I am, you tend to do
a number of things:
1) buy a brand name you have some confidence in: with 5 1/4 inch disks, I used
to buy Dysan. I've been buying Sony microfloppies since they were the only
supplier; I have yet to get a bad one, but that could happen tomorrow.
2) never save a few cents by putting valuable data on a cheap disk, or an SS
disk which has been formatted DS. This might work most of the time, but I'm
not confident it will work for me (Manis' Law: the probability of a disk
failing is directly proportional to the importance of its contents).
3) keep backups anyway.
If I were not a computer scientist but rather an expert in magnetic recording
media, I might very well know enough to be able to spend a few dollars less a
year on disks. But, being ignorant in these matters, I don't really buy
assurances that "I've formatted 8 zillion SS disks DS, and never had a
problem." Maybe so, but I don't want to take the chance.
Vincent Manis | manis@cs.ubc.ca
The Invisible City of Kitezh | manis@cs.ubc.cdn
Department of Computer Science | manis@ubc.csnet
University of British Columbia | {ihnp4!alberta,uw-beaver,uunet}!
<<NOTE NEW ADDRESS>> | ubc-cs!manisrosenkra@Alliant.COM (Bill Rosenkranz) (04/29/88)
----- in spite of the fact that this discussion is interesting, educational, and helpful, i think the *real interesting* question was the one originally asked: is it true that computer X uses one side of a SS disk while computer brand Y uses the other? as originally stated, this would mean every SS disk *IS* really certified on both sides and we can all save at least 30 to 50% by buying SS certified disks (which would essentially give you DS certified disks). i think computer "X" was a mac and computer "Y" was probably ibm/atari/... how 'bout it...does anybody know for sure? -bill (it seems unlikely since the certification process does cost something and would thus have to be done on both sides of every disk produced) (still, i would not put it past this industry to do something like that...)
S071768@UMRVMA.BITNET (Kevin Schneider) (04/29/88)
It was stated that MS-Dos does not recognize SS (3.5) disks. While that may be
advertised (in fact, I thought that for a while), Thanks to the instructions
included with PC-Ditto, I have formatted 3.5" SS disks on my PC clone running
PC Dos 3.2 that work just fine on the ST. It is done by specifying in the
config.sys file
device=driver.sys/d:x/t:80/s:9/h:1
where x is 0 or 1 depending on which physical drive you
want this assigned to.
So SS 3.5 disks can be used with an IBM. But I couldn't find this info
in the PC-Dos manual.
Acknowledge-To: <S071768@UMRVMA>cochrane@spot.Colorado.EDU (COCHRANE JIM T) (04/29/88)
In article <1669@alliant.Alliant.COM> rosenkra@alliant.UUCP (Bill Rosenkranz) writes: >in spite of the fact that this discussion is interesting, educational, and >helpful, i think the *real interesting* question was the one originally >asked: is it true that computer X uses one side of a SS disk while computer >brand Y uses the other? as originally stated, this would mean every SS >disk *IS* really certified on both sides and we can all save at least 30 >to 50% by buying SS certified disks (which would essentially give you >DS certified disks). >... >-bill I'm afraid I can't answer your question, but I have an observation that appears to be relevant to this discussion. I've noticed that in at least a couple ads I've seen, mail order houses were offering double sided disks for the same price as for single sided disks. Whether this is because DS and SS disks are essentially the same or whether it's for some other reason I cannot say. Perhaps others on the net would have some kind of explanation for this phenomenon.
BHOLMES@WAYNEST1.BITNET (Brian Holmes) (04/29/88)
I have formated 360K 3 1/2 inch disks on a PS/2 model 80 running DOS 3.3 using the following command: FORMAT A:\T:9\S:80 I believe this is correct?
wes@obie.UUCP (Barnacle Wes) (04/29/88)
In article <167@obie.UUCP>, wes@obie.UUCP (Barnacle Wes) rambles: % Nope. The single-sided 3.5" disk drives write on the top. The O.S. % has nothing to do with this. A 3.5" SS disk drive is undefined in the % MS-DOS world, by the way - MS-DOS only recognizes 720K and 1.44M 3.5" % disks. In article <613@lakesys.UUCP>, rich@lakesys.UUCP (Rich Dankert) writes: > Wrong. MS-DOS will work with 360K SS disks also. All one hase > to do is change the information in the config.sys file and one can > make MS-DOS work with SS drives, a 5 1/4 and a SS drive or DS drive > and a SS drive or any combination of the above. Yes, a couple of days ago, I re-read the options to the DEVICS.SYS device driver. You can make MS-DOS recognize just about any combination that the floppy controller can handle now; you just can't format them with the DOS formatter (which is brain-dead anyhow). -- /\ - "Against Stupidity, - {backbones}! /\/\ . /\ - The Gods Themselves - utah-cs!uplherc! / \/ \/\/ \ - Contend in Vain." - sp7040!obie! / U i n T e c h \ - Schiller - wes
wheels@mks.UUCP (Gerry Wheeler) (04/30/88)
In article <1669@alliant.Alliant.COM>, rosenkra@Alliant.COM (Bill Rosenkranz) writes: > in spite of the fact that this discussion is interesting, educational, and > helpful, i think the *real interesting* question was the one originally > asked: is it true that computer X uses one side of a SS disk while computer > brand Y uses the other? > > -bill Agreed -- I don't think that question was ever answered. In my experience, having opened several single-sided drives, both 5.25" and 3.5", they all use the bottom. That is, they read/write the side of the diskette opposite the label. The upper part of the arm arrangement in the drive usually has just a felt pressure pad. I haven't dealt with any Mac drives, but I can't imagine they would go so far as to severely modify an existing drive. (Maybe Mac never even used SS drives?) -- Gerry Wheeler Phone: (519)884-2251 Mortice Kern Systems Inc. UUCP: uunet!watmath!mks!wheels 35 King St. North BIX: join mks Waterloo, Ontario N2J 2W9 CompuServe: 73260,1043
easterb@ucscb.UCSC.EDU (William K. Karwin) (05/03/88)
In article <5735@sigi.Colorado.EDU> cochrane@spot.Colorado.EDU (COCHRANE JIM T) writes: >In article <1669@alliant.Alliant.COM> rosenkra@alliant.UUCP (Bill Rosenkranz) writes: >>...is it true that computer X uses one side of a SS disk while computer >>brand Y uses the other? as originally stated, this would mean every SS >>disk *IS* really certified on both sides and we can all save at least 30 >>to 50% by buying SS certified disks (which would essentially give you >>DS certified disks). >>... >>-bill > >...a couple ads I've seen, mail order houses were offering double sided >disks for the same price as for single sided disks. Whether this is >because DS and SS disks are essentially the same or whether it's for some... I have been having disk access errors recently with disks that checked out okay with disk verifying programs. I took this disk and my 1040ST to my local maintenance guy. After doing some tests, he concluded that I should stop using my brand of SS disks. He said many SS disks are verified for the Mac drives which have the heads on the opposite side as ST's drives. He once tested 100 SS disks, reading, writing, formatting repeatedly. He determined that about _20_ of them developed seriously bad data corruptions. He recommends Sony SS disks, because he says they are verified on both sides, so that they can be used as SS disks on either Mac or ST or what-have-you drives. So I am going to trade my disks to someone with a Mac. /* ------------------------------------------------------------------ */ William K. Karwin ARPA : easterb@ucscf.ucsc.EDU "As my will, so mote it be" UUCP : ...!ucbvax!ucscc!ucscf!easterb - evil guys BITNET: easterb@ucscf.BITNET
john@stag.UUCP (John Stanley) (05/08/88)
In article <3139@saturn.ucsc.edu> easterb@ucscb.UCSC.EDU (William K. Karwin) writes: > >I have been having disk access errors recently with disks that >checked out okay with disk verifying programs. I took this disk >and my 1040ST to my local maintenance guy. After doing some >tests, he concluded that I should stop using my brand of SS >disks. > [questionable head info deleted] > >He recommends Sony SS disks, I do too. I have over 400 disks formatted double-sided. Over 90% of them are Sony single-sided. Out of all the SS formatted as DS, only 4 of the Sonys have failed on me. I've tried this with other brands and generics (many that are suppost to be "made by Sony"), but with significantly higher failure rates on all of them. (Disclaimer: This info only covers using 3.5" disks with an Atari ST. I have very little knowledge as to how well this would work on a Mac or any other machine...) --- John Stanley (dynasoft!john@stag.UUCP) Software Consultant / Dynasoft Systems
bdeskin@cognos.uucp (Bob Deskin) (05/10/88)
Newsgroups: comp.sys.atari.st Subject: Re: SS disks Summary: Expires: References: <184chad@byuvax.bitnet> Sender: Reply-To: bdeskin@cognos.UUCP (Bob Deskin) Followup-To: Distribution: Organization: Cognos Inc., Ottawa, Canada Keywords: In article <184chad@byuvax.bitnet> chad@byuvax.bitnet writes: > >Question: Is it true that MACs use the top of the disk while Atari/IBM >use the undersides? If that is true, then all SSDD disks are *certified* >DSDD disks as the manufacturers wouldn't know which computer is going >to be used and therefore which side to certify... > >That is what I have heard. If it is true, then it is the biggest scam >around. What you say may be true, however, as I understand it, there is no question about whether both sides of a SSDD disk are usable, its whether both sides can be used with assurity at the same time. Again, as I understand it, a DSDD disk has a slightly thicker platter so as to separate the two sides more. This prevents interference when reading. Remember that reading a disk means electronically reading the magnetic encodings. If, when reading the top side, you pick up the bottom, well, you are going to get garbage. I have heard of many people using SSDD disks as DSDD without difficulty, but they make sure they have backups. -- Bob Deskin decvax!utzoo!dciem!nrcaer!cognos!bdeskin Cognos Incorporated P.O. Box 9707 (613) 738-1440 3755 Riverside Dr. Ottawa, Ontario, CANADA, K1G 3Z4
Jinfu@cup.portal.com (05/13/88)
Not really related to this topic but I can't help this. Today I saw a bumper sticker saying: SS/DD -- Same shit different day You can come up your DS/DD defintion.
Friesen@HIS-PHOENIX-MULTICS.ARPA.UUCP (06/05/88)
Someone recently posted saying that SS disks are not good to be used as
DS disks. I own a 1040 ST (with DS disk drives), and I don't own one DS
disk. I format my SS disks for DS use. I have owned my Atari for a
year now (I bought it May 3, one year ago) and I haven't had any
problems with losing data, however in that time I have had to have my
heads alinged twice, could this be a side efect of using SS disks for a
DS drive?
> Is it true that computer brand X uses one side of a SS disk, while >
computer brand Y uses the other side?
(My two cents)
I was told (by my dealer) the only difference between SS and DS disks is
that the manufacturer dosen't check the second side of the disk, but the
are still put together the same. If this is true, I find it hard to
believe that one computer would store data on one side of the disk,
while another computer stores it on the other side, when only one side
has been certified.
Aric Friesen
P.S.
Someone gave me two brand new unopened Nashua disks, and one wouldn't
format. That means 50% of the Nashua disks that I own didn't format. I
also have heard similar complaints from Mac owners, in other words, I
wouldn't recommend buying Nashua disks.
Addresses: Genie: A.FRIESEN ARPA: Friesen%PCO@BCO-MULTICS.ARPA
"Lenny, ya durned fool, ya bought an Amiga!" "Gee George, I squashed the
mouse!"
---"Of Mice and Men"