Subject: 3-1/2" Floppy Market Cornered

From: "R. D. Davis" <[email-masked]>
Date: Wed May 21 10:08:31 2003

It appears that I may have cornered, at least the local, market for
3-1/2" floppies.  A recent thrift-shop find was a computer-paper sized
box (That is, the size of a box of real computer paper: wide greenbar.
Now, hopefully no one is going to ask a question like "what's
greenbar?") packed nearly full of, mostly unboxed, and used, floppies.
Nothing useful on them, just a bunch of PeeCee software for Windoze,
so I don't have to worry about overwriting anything valuable. :-)

-- 
Copyright (C) 2003 R. D. Davis The difference between humans & other animals: 
All Rights Reserved            an unnatural belief that we're above Nature & 
[email-masked]  410-744-4900  her other creatures, using dogma to justify such
http://www.rddavis.org         beliefs and to justify much human cruelty.

---

From: "TeoZ" <[email-masked]>
Date: Wed May 21 10:08:43 2003

Any original games on those 3.5's?

I generally buy my disks bulk on ebay when I see a bargain. Most of my old
16 bit computers use those rare 3.5 DD disks, found 500 new for $20 once..
should have purchased alot more.

---

From: "Zane H. Healy" <[email-masked]>
Date: Wed May 21 10:09:07 2003

>greenbar?") packed nearly full of, mostly unboxed, and used, floppies.

What's Greenbar? ;^)

Seriously, it wouldn't surprise me if there are a fair number of people here that don't know what you're talking about.  Me, I've worked on Mainframes, so am very familiar with what you're talking about.

BTW, did anyone ever make 8 1/2x11" tracker-fed greenbar?  I'd love to get ahold of a box or two for the LA75 on my PDP-11.

		Zane

-- 
--
| Zane H. Healy                    | UNIX Systems Administrator |
| [email-masked] (primary)    | OpenVMS Enthusiast         |
|                                  | Classic Computer Collector |
+----------------------------------+----------------------------+
|     Empire of the Petal Throne and Traveller Role Playing,    |
|          PDP-10 Emulation and Zane's Computer Museum.         |
|                http://www.aracnet.com/~healyzh/               |

---

From: Chad Fernandez <[email-masked]>
Date: Wed May 21 10:09:32 2003

R. D. Davis wrote:
> greenbar?"

That's an ice cream bar thats been sitting out for too long, right?

Chad Fernandez
Michigan, USA

---

From: "R. D. Davis" <[email-masked]>
Date: Wed May 21 10:09:57 2003

> That's an ice cream bar thats been sitting out for too long, right?

Yes (this answer provided for the benefit of those who pretend to have
some knowledge of computers and don't know what greenbar is ;-).
...and as we all know, a box of greenbar paper is a box of special
paper, used by the ice-cream companies, for collecting and recycling
greenbar.

---

From: Brian Chase <[email-masked]>
Date: Wed May 21 10:11:15 2003

On Tue, 20 May 2003, Zane H. Healy wrote:

> BTW, did anyone ever make 8 1/2x11" tracker-fed greenbar?  I'd love to
> get ahold of a box or two for the LA75 on my PDP-11.

Of course.  It was very widely used for printing with 8-bit micros
during the 1980s.  I remember using lots of it when I was in elementary
school.  It does still seem to be available for purchase:

  <http://gotoforms.com/templates/frmTemplateM.asp?CatalogID=158&Zoom=Yes&SubFolderId=20>

I can't vouch for the vendor.  I found them with a bit of googling.

-brian.

---

From: "Fred Cisin (XenoSoft)" <[email-masked]>
Date: Wed May 21 10:11:31 2003

On Tue, 20 May 2003, Zane H. Healy wrote:
> What's Greenbar? ;^)
> BTW, did anyone ever make 8 1/2x11" tracker-fed greenbar?

yes

---

From: Jim Battle <[email-masked]>
Date: Wed May 21 10:11:45 2003

Zane H. Healy wrote:
...
> BTW, did anyone ever make 8 1/2x11" tracker-fed greenbar?

That should be "tractor-fed", not "tracker-fed".

---

From: John Lawson <[email-masked]>
Date: Wed May 21 10:11:57 2003

> That should be "tractor-fed", not "tracker-fed".

 Oh - so that also explains 'Lucky Pierre, the Fur-Tractor'.

  :{}

John

---

From: ben franchuk <[email-masked]>
Date: Wed May 21 10:13:13 2003

>  Oh - so that also explains 'Lucky Pierre, the Fur-Tractor'

That is only if the CAT is  sleeping on the printer. :)

---

From: [email-masked] (Tony Duell)
Date: Wed May 21 10:15:07 2003

> 16 bit computers use those rare 3.5 DD disks, found 500 new for $20 once..

Odd, most of my 16 bit machines use 8" disks...

Are 3.5" DD floppies that hard to obtain? I've seen them on sale in high 
street shops over here in the last week or so (at twice the rpice of the 
HD ones, of course...). If they're getting hard to find, I'd better stock 
up, as my 9114s need them...

-tony

---

From: David Holland <[email-masked]>
Date: Wed May 21 10:15:46 2003

> up, as my 9114s need them...

I thought you could use 3.5" HD/DD disks in a DS/DD drive just fine.  At
worst a piece of tape over the "wrong" hole if necessary. 

I know 5.25" HD disks don't work as 5.25" DS disks..  but I thought 3.5"
disks did.. 

? (Of course, I haven't tried it recently enough to remember either.) 

David

---

From: Joe <[email-masked]>
Date: Wed May 21 10:16:24 2003

>worst a piece of tape over the "wrong" hole if necessary. 

  Nope the HP drives are fussy. They won't use the HD disks. I tried them
in the 9114, 9133, 9121, 9122, 9153, Integral and others and NONE of the HP
drives will format the HD disks.

>I know 5.25" HD disks don't work as 5.25" DS disks..  but I thought 3.5"

   They usually will for PCs but not for the HPs. 

   Joe

---

From: [email-masked]
Date: Wed May 21 10:17:30 2003

On Tue, 20 May 2003, Zane H. Healy wrote:

> Seriously, it wouldn't surprise me if there are a fair number of people
> here that don't know what you're talking about.  Me, I've worked on
> Mainframes, so am very familiar with what you're talking about.
>

I have a box of GP 8.5x11" greenbar.

Peace...  Sridhar

---

From: David Holland <[email-masked]>
Date: Wed May 21 10:19:55 2003

Hmmm, I'll have to try it out on the IIgs, which is the only place
I'd have need of DS/DD 3.5" disks....

Thought I could get away w/ DS/HD 3.5" disks with it, perhaps I should 
keep my eyes open for DS/DD 3.5" disks in the thrift stores as well. 

thanks, (I think.. :-)  )

David

PS: Gee, didn't I get my DS/DD/HD abbreviations wrong in the previous 
message.. <doh>

---

From: "TeoZ" <[email-masked]>
Date: Sat May 24 19:13:18 2003

My atari ST, Amiga 500,1200 Use them. DD disk drives were only used for a
few years so everybody went to HD production (still in use).

---

From: "TeoZ" <[email-masked]>
Date: Sat May 24 19:13:31 2003

DD and HD use different magnetic media. Formatting a HD disk in a DD only
drive will create a disk that loses data if its readable at all.

---

From: Ethan Dicks <[email-masked]>
Date: Sat May 24 19:14:51 2003

> few years so everybody went to HD production (still in use).

I also have a Zenith 8-bit laptop that has a pair of pop-up DD drives.
Mine has a DOS3.3 boot disk with MS-DOS Kermit on it.  I also have a
packet driver for a Xircom PE3 - I use it as a portable terminal.

-ethan
The New Yahoo! Search - Faster. Easier. Bingo.
http://search.yahoo.com

---

From: [email-masked] (Tony Duell)
Date: Sat May 24 19:17:13 2003

> worst a piece of tape over the "wrong" hole if necessary. 

Not if you value your data (and I do -- what's the point in writing 
something to disk if you don't intend to read it back again?).

The coercivity of the media _is_ different between the DD and HD 3.5" 
disks. Not very different, but different enough that you _will_ have 
reliabilty problems.

-tony

---

From: [email-masked] (Tony Duell)
Date: Sat May 24 19:18:54 2003

> few years so everybody went to HD production (still in use).

2 points : 

1) The HP 9114 drive that I mentioned used _original_ DD drives, rotating 
at 600rpm. When these drives were designed, the HD disk hadn't been 
thought of...

2) Even now, HD drives have a switch to detect the hole in the HD disk, 
and one thing this switch does is to change the head write current to 
cater for the different coercivity of the DD and HD media. 

Have you got _proof_ (either from schematics, or by actually measuring 
the write current in an opertation drive) that the write current is the 
same for both DD and HD disks in a correctly-functioning name-brand 
drive? Becasue I am darn sure it isn't!

-tony

---

From: "Fred Cisin (XenoSoft)" <[email-masked]>
Date: Sat May 24 19:19:23 2003

> drive? Becasue I am darn sure it isn't!

No, but "DD" drives initially, for obvious reasons, did not have a switch. 
Many people who were oblivious to differences in reliability used HD
diskettes in DD machines, and thought that they worked correctly.
I think that THAT is what he meant by "everybody went to HD" in reference
to his Atari, Amiga, etc. experiences.

And, I can easily show you "HD" drives that do not have a switch!  IBM did
not put a switch in their original "1.44" drives in PS/2's.  Some users of
those claim that DD diskettes work correctly.  (and then later complain
about the COMPUTER being "unreliable")

At no point has the price differential been so extreme as to justify using
the wrong diskette on a regular basis.  Admittedly, there can be
"emergencies", where the correct diskette is unavailable that might result
in a need to make do with a wrong one.

---

From: Marvin Johnston <[email-masked]>
Date: Sat May 24 19:19:37 2003

This brings up an interesting point; how do you tell the difference
between DD and HD diskettes? My usual method was to try and format them
on a DD drive, and if they formatted, they were DD :). Is there a better
method?

-- 
-------------------------------------------
ebaY's Security Breach and Coverup
http://www.auctionguild.com/generic110.html

---

From: "Fred Cisin (XenoSoft)" <[email-masked]>
Date: Sat May 24 19:19:51 2003

> on a DD drive, and if they formatted, they were DD :). Is there a better

YES!
That method will let some slip through that "almost" work.

3.5":
Find one of each that are known, and labeled by the 
manufacturer.  Sometimes the labeling will refer to the UNFORMATTED
capacity and say 1M v 2M.
Find the write protect hole.  Notice that on the HD diskette, there is
another similar hole in one of the other corners.
Go with whether or not the manufacturer put in that other "media
identification" hole.  Once HD came out, every RESPONSIBLE manufacturer 
of HD drives put in a switch to check for that hole.  But if you have IBM
equipment, then YOU have to check.

Also for 3.5":
2.8M (4M unformatted) (Barium ferrite?) has a different media
identification hole.  
Floptical (20M) has a different media identification hole.

Although LS120 drives will also take "regular" 3.5" diskettes, they are
thoroughly different in appearance.

5.25":
There is usually a slight difference in color.
Also, when HD came out, they discontinued reinforcing the center hole.
Therefore, if there is no reinforcement, then it is EITHER a very early
"low" density diskette, or is an HD diskette.
If there IS a reinforcement, then it is either a DD diskette, or it is an
unreinforced diskette that somebody added a reinforcement to, by using an
aftermarket jig, such as from Inmac, or the Berkeley Microcomputer (later
Xenosoft) "Flip-Jig".

Also watch for hard sectored diskettes (more than one hole in the mylar
goes by the index hole in the jacket if you manually turn it.)

8": 
I don't think that there are any density differences, but single and
double sided diskettes are different.  The position of the index hole is
different.

3": 
I don't think that there are any density differences, but single and
double sided diskettes are different.  I don't remember the difference -
holes?

3.25":
All the same.  But watch out that there are a lot of alignment diskettes
extant, and it would be a shame to wipe one of those for routine data
storage.

--
Fred Cisin                      [email-masked]
XenoSoft                        http://www.xenosoft.com

---

From: David Holland <[email-masked]>
Date: Sat May 24 19:20:06 2003

I always thought the difference was the number of hole's at the 
end of the disk..  One of the hole's is for write protect.  The others
presence (or absence) indicates HD, or DD.  (HD disks had the second
hole) 

But then again, I'm the guy who (mistakenly) thought 3.5" HD disks 
would work as DD. :-) 

David

---

From: "Fred Cisin (XenoSoft)" <[email-masked]>
Date: Sat May 24 19:20:34 2003

> presence (or absence) indicates HD, or DD.  (HD disks had the second

That's right

> But then again, I'm the guy who (mistakenly) thought 3.5" HD disks 

They will.  just not very reliably.

---

From: [email-masked] (Tony Duell)
Date: Sat May 24 19:33:31 2003

> No, but "DD" drives initially, for obvious reasons, did not have a switch. 

True DD drives probably still don't :-).

Incidentally, the Sony drive used in the HP9114 that started this 
discussion does have a switch that lines up with the HD-hole. It's used 
to detect that a disk has been inserted, and therefore, these drives 
don't even recognise an HD disk (they think the drive is empty)

> not put a switch in their original "1.44" drives in PS/2's.  Some users of

How did they work? Did they use the HD write current for all disks? Or 
did they use the density select line from the controller, like the 5.25" 
1.2M drives do? I would hope the latter.

> the wrong diskette on a regular basis.  Admittedly, there can be

FWIW, the street price in the UK at the moment is at least a factor of 2 
(with the DD being double the price of the HD). This still has not 
convinced me to risk my data :-)

-tony

---

From: [email-masked] (Tony Duell)
Date: Sat May 24 19:33:47 2003

> another similar hole in one of the other corners.

That, surely is a reliable method for name-brand disks.

> double sided diskettes are different.  I don't remember the difference -

This is the confusing one IMHO. All 3" disks are double sided, but some 
drives are single-head and use the disks as 'flippies'. 

However, Amstrad, who were the major user (at least in the UK) of 3" 
disks fitted 40 cylinder single-head or 80 cylinder double head drives to 
their machines. With the result that 80 cylinder-capable disks were often 
called 'double sided' and 40-cylinder ones 'single sided'. 

But 40 cylinder double-head drives exist (I have one on my CoCo), and 
obviously from the above they are reliable using so-called 'single-sided' 
disks.

AFAIK the pattern of holes and notches is the same in all disks.

-tony

---

From: "Fred Cisin (XenoSoft)" <[email-masked]>
Date: Sat May 24 19:35:04 2003

> don't even recognise an HD disk (they think the drive is empty)

Hmmm.  So "wrong disk" is equated to "no disk".
Did they PLAN it that way to reject the other disks that were being
planned for, (I assume that they knew about the future diskette types
before we did), or did they just get lucky?

> 1.2M drives do? I would hope the latter.

Yes.  The "density" was software controlled.  You could still format a
"720K" by using /T:80 /N:9, or /F:2, or later /F:720.  
NOTE: XP has discontinued F:2 and F:720, but /T:80 /N:9 still works.

> convinced me to risk my data :-)

Different people place different values on their data.

...and now that AOHell sends out CD's, we will all have to BUY our
diskettes.

--
Grumpy Ol' Fred        [email-masked]

---

From: "Fred Cisin (XenoSoft)" <[email-masked]>
Date: Sat May 24 19:35:20 2003

> drives are single-head and use the disks as 'flippies'. 

Thanks
I couldn't remember for sure.
But, IIRC, the double sided drives would not let you insert a diskette
upside down, and therefore were incapable of reading the second side of a
flippy other than backwards, which was not supported by the controllers.

---

From: [email-masked] (Tony Duell)
Date: Sat May 24 19:36:11 2003

[3" disks]

> upside down, and therefore were incapable of reading the second side of a

Yes. There's an off-centre notch in the front edge of the disk. On the 
double-head drive, there's a metal bracket that slots into this notch 
which prevents the disk going in if upside-down.

The better class of single-head drive have an optical sensor to detect 
this notch. The In-Use LED is green if the disk is in one way up, and red 
if it's the other way up. Or at least the one in my Einstein behaves like 
that,

> flippy other than backwards, which was not supported by the controllers.

True :-(

-tony