Talk:History of the floppy disk

Floppy disk internal diagram
←The File:Floppy disk internal diagram.svg has the density-detect tab mislabeled as the write-protect tab. SalineBrain (talk) 22:19, 11 February 2010 (UTC)

It's not only labeled incorrectly, it's drawn incorrectly. The hole that #1 is pointing at clearly appears to be blocked - as if the write protect slide had been closed (although that should be at the upper left corner when looking at the bottom of a 3.5" floppy in that orientation. I'd take a shot at fixing it, but Gimp doesn't appear to edit SVGs...  Rwessel (talk) 05:35, 12 February 2010 (UTC)


 * I can and have edited it in PaintShop Pro but I can't save into SVG - JPG, PNG, whatever, but not SVG Tom94022 (talk) 20:49, 12 February 2010 (UTC)
 * I found an online converter from PNG to SVG. What next - should I just go ahead and replace the image in the Commons, update the labels (limited to English) or is there a better way to update? Tom94022 (talk) 20:52, 12 February 2010 (UTC)


 * I'm pretty sure you really don't want to do that. An SVG is a vector graphics format, and converting it to a bitmap, editing that, and then converting it back will result in a really bad SVG.  One of the features of an SVG is that they scale, since what it contains is drawing commands (in fact SVG is XML, so you can actually edit wit as text), rather than a bitmap.  Converting a bitmap (like a PNG) to an SVG will likely result in something that displays, but will scale very badly.  What needs to happen is someone needs to edit the SVG directly, or use an editor that explicitly understands vector graphics and keeps the file as such for the whole edit process - *not* like what GIMP or Paintshop Pro (presumably) do, which is render the SVG into a bitmap, and then let you edit that.   Rwessel (talk) 00:29, 13 February 2010 (UTC)


 * Actually it looks pretty good in my browser :-). I'd upload a copy, but right now Wiki file upload seems to not be working.  Tom94022 (talk) 05:02, 13 February 2010 (UTC)
 * So here it is, now what?→
 * Tom94022 (talk) 05:12, 13 February 2010 (UTC)


 * If you go to the image page, and scale each to "2000px" you'll see the differences pretty clearly. Anyway, it seems the original artist is no longer very active on Wikipedia (I was going to ask them to do the change).  From reading some of their stuff, it seems Inkscape (http://www.inkscape.org/) is a useful open source editor for SVGs.  I download a copy and it seems to let me poke at the SVG in vector format, but really haven't had time to get into it.  I'm also unclear about the policy for editing a featured image, but there's been at least one edit of this image by a different user in the past.  Rwessel (talk) 08:19, 13 February 2010 (UTC)


 * All i see is a little banding in the grey areas. I think I will link the article to the corrected figure while we figure out how to update the original.  Maybe we don't have too - just put a warning on it.  Tom94022 (talk) 22:18, 13 February 2010 (UTC)

- There is nothing wrong with the current version of the original Wikimedia commons image (File:Floppy disk internal diagram.svg), which was last edited on 24 April 2011—Improved fine detailing; correct oxide coating colour; open shutter on second image to show where the disc is read; switched to a nominal 10 tracks instead of 11 and cleaned it up to use act. Here is the image as it looked in Feb. 2010—the issues described above have been corrected. This image showing details of the 3.5 in. floppy internals is in the floppy disk article, and really belongs there, rather than in history of the floppy disk. Since the image is redundant here, and since the edit of 13:02, 30 November 2011 added yet another image to the article which had a side effect of making the internal diagram image stomp on the references text in Google Chrome widescreen window displays, I am deleting the image from this article. The "corrected" file adds a pointer to the write protect tab, but the image detail is not as accurate. Wbm1058 (talk) 05:41, 26 January 2012 (UTC) Wbm1058 (talk) 15:45, 26 January 2012 (UTC)

The image discussed here was added to the floppy disk article with this edit of 21:47, 8 October 2010. Wbm1058 (talk) 17:13, 26 January 2012 (UTC)

Dispute claims on provenance of writable control store
The 360/25 and the 360/85 had writable control store before the System/370, although only the 360/85 used semiconductor memory for it. Both the 370/155 and the 370/165 had read only storage. Shmuel (Seymour J.) Metz Username:Chatul (talk) 00:06, 22 June 2010 (UTC)
 * So my footnote should have fixed the dispute. May I suggest rather than just putting disputes about you try and change the articles to make them better?  Tom94022 (talk) 00:17, 22 June 2010 (UTC)


 * There's still a dispute; the 360/25 had a writable control store and both the 370/155 and 370/165 stored microcode in ROS.


 * I did change the article to make it better; you reverted my change. May I suggest that you do some research before reverting changes? Even the Functional Specifications would have told you that two out of the three initial System/370 processors used ROS. Shmuel (Seymour J.) Metz Username:Chatul (talk) 00:38, 22 June 2010 (UTC)


 * I did not revert your change, I made further changes to make it clear that the FDD was developed for the S/370 product line. The term writable control store does not appear in the article so the M25 is irrelevant.  The M155 and M165 are an interesting exception to the S/370 family usage of volatile read/write semiconductor for microcode so I can fix that with a minor word change.  I am not the first editor to suggest you don't throw around dispute tags, don't shoot the messenger.  Tom94022 (talk) 01:36, 22 June 2010 (UTC)
 * You didn't use undo to remove my change, but you did remove it. However, Disputed was the wrong tag to use; I should have used Disputed-section. IAC, your last change appears to answer my objection.
 * Did you deliberately drop the comma before so whenever the power was turned?
 * I tend to not use a lot of commas so if u want one there go ahead. Tom94022 (talk) 13:52, 22 June 2010 (UTC)
 * Also, do you have any problem with adding a footnote citing the models where that does not apply? If you have no problem with a footnote, would it be better to just mention the models, cite the functional specifications or cite a CE manual? Shmuel (Seymour J.) Metz Username:Chatul (talk) 10:48, 22 June 2010 (UTC)
 * No objection (and you didn't have to ask). Tom94022 (talk) 13:52, 22 June 2010 (UTC)
 * Okay, I added a footnote just listing the models. I'll add the Functional Specifications manuals if someone believes that to be necessary; the CE manuals would probably be TMI. Shmuel (Seymour J.) Metz Username:Chatul (talk) 15:56, 22 June 2010 (UTC)

Citation for term ICPL?
The manuals that I have use the term Initial Micorprogram Load (IML); does anybody have a citation of ICPL being used? Shmuel (Seymour J.) Metz Username:Chatul (talk) 15:56, 22 June 2010 (UTC)
 * Its used in both Pugh, "IBM's 360 ..." and Daniel, "Magnetic Recording ...". BTW, Daniel makes the point that the intent was for all System 370 to use WCS, so the 155 and 165 really are anomalies.  Tom94022 (talk) 01:32, 23 June 2010 (UTC)

ICPL vs. IML
This is a continuation of the above, based on a couple of recent edits. While ICPL seems to have a few uses, the Pugh reference in particular, most of the rest of the Google hits ("icpl microcode" yields only 1450 hits), that I checked seems to either be copying Pugh or the Wikipedia article. Googling "iml microcode" yields 200K hits. In addition, the term IML is still the one IBM uses. For example, here are S/370 (~1975), ESA (~1988), and zArch (current) P-of-O's, each using IML (there's an IMPL in the earliest), but no ICPLs. And "control program" is used repeatedly to mean "operating system":

http://bitsavers.trailing-edge.com/pdf/ibm/370/princOps/GA22-7000-4_370_Principles_Of_Operation_Sep75.pdf http://bitsavers.trailing-edge.com/pdf/ibm/370/princOps/SA22-7200-0_370-ESA_Principles_of_Operation_Aug88.pdf http://publibfi.boulder.ibm.com/epubs/pdf/dz9zr009.pdf

Also this early IBM "An Introduction to Microprogramming" uses IMPL:

http://bitsavers.trailing-edge.com/pdf/ibm/370/GF20-0385-0_An_Introduction_to_Microprogramming_Dec71.pdf

And the current "IBM zEnterprise EC12 Technical Guide" uses IML exclusively:

http://www.redbooks.ibm.com/redbooks/pdfs/sg248049.pdf

As near as I can tell, ICPL is used, but fairly rarely, and IML is much more common. Rwessel (talk) 04:56, 8 April 2014 (UTC)


 * Google searches are not a particularly good basis for ranking. As near as I can tell at the time of the 370 announcement IBM described the feature as "reloadable control storage" so I tend to like "control program" and ICPL as opposed to "microcode" and "IMPL." So I made it consistent.  Pugh of course had access to internal IBM documentation so that is one more reason to favor ICPL.  But it could go the other way since IMPL and microcode are used in the S/370 135 and 145 manuals.  Tom94022 (talk) 06:16, 8 April 2014 (UTC)
 * BTW, that's IMPL not IML Tom94022 (talk) 06:22, 8 April 2014 (UTC)


 * Yes, IBM called the microcode storage "control storage", but "control program" in IBMs mainframe usage has never meant the microcode, or the stuff loaded off the (microcode) floppy, but rather the OS, which was loaded during the IPL process, which happened after the IML. In fact an IPL (usually off a hard disk, but sometime off other media, but never from the microcode load floppy*) could happen many times after the IML process, which was necessary only when you powered the machine on (you could reboot - aka IPL - the OS many times thereafter without reloading the microcode).  IMPL, FWIW, was used in early S/370 documentation, but was dropped in favor of IML before too long.  In my copy of GA22-7000-5 (circa 1976 P-of-O) is was still IMPL, the -7 version of the same manual (circa 1981) changed to IML, with the comment "Note: the name IMPL controls was used in earlier descriptions."  I don't have a -6 available to verify, but I know we were already calling it IML before 1980.  While Pugh may have had access to internal IBM documents, AFAIK IBM never used the term ICPL in any externally available S/370 documents, rather using IM(P)L exclusively.  Actually there is one exception: in a VSE message (0P54), referring to a I/O device (not the S/370) not having been fully brought up.


 * *Theoretically, you could have IPL'd off a 3540 diskette drive (and who knows, perhaps someone actually did that), but that was not where the microcode was loaded from, which was a floppy dedicated to just that purpose, and not available as a general use peripheral (which the 3540 was). Rwessel (talk) 08:10, 8 April 2014 (UTC)


 * I'm not sure that in the IBM world of the early 1970s that either CP only meant OS or that CP "never" meant microcode but I will research it. We have two reliable sources, both historians, with access to original sources who after research say ICPL; other people later say I(M)PL but I suggest they are not as reliable as the two historians.  Personally my recollections from that time period favor ICPL as an IBM term.  But maybe the solution is to drop all acronyms and just say what IBM said, something like, "... loading microcode into the the writeable control storage of soon to be announced their System/370 mainframes."
 * FWIW the first public availability of the FD was not in a S/370 mainframe but instead the 2835 Storage Control Unit for the 2305 Fixed Head Disk File. It maybe that ICPL comes from writable control storage usage in other than mainframes.  IBM San Jose did both the FD and the many SCUs. Tom94022 (talk) 17:41, 9 April 2014 (UTC)

Floppy Disk Patent Dispute
I found this document which looks to be an excellent resource but I don't know when I'll have time to give it much attention so if anyone wants to take a look at it here is a link. It will download as a Word document and is an official government document published by United States International Trade Commission David Condrey (talk) 08:57, 13 July 2014 (UTC)

Internal IBM 33FD Name "IGAR" Clarification
In Note 14:Oral History Panel on 8 inch Floppy Disk Drives.,, Ed. Jim Porter, 2005 - pg 9 "IBM did introduce what they called the IGAR, the model 33FD, along with their 3740 data entry system."

The name IGAR was the IBM San Jose internal identification code for the newly invented (Patent US3846840 A) & developed ferrite (plus Barium Titanate Ceramic, aka BTC) R/W & tunnel erase transducer. Porter's recollection that IGAR refers to the 33FD drive is incorrect. The IGAR head was specifically invented and intended as a plug-compatible replacement for the original laminated Mu-Metal head in the 33FD (and prior 23FD) floppy disk drive. The name IGAR was discussed and decided by the co-inventors of the R/W head (William Childers, Karl Elser, & Phil Peterson) in Karl's office upon deciding to build a feasibility / proof of concept prototype.

The intended advantage of the invention was two-fold:
 * 1. Dramatically reduce the IBM internal manufacturing costs of the then current Mu-Metal R/W/tunnel erase transducer used in IBM's 23FD previously and the then currently planned shipment of the 33FD, from upwards of $300/R/W head to less than $20/R/W head. With the PC development IBM sold licenses to other manufacturers, principally in Japan & Taiwan, so that by April 1984 the head was selling in lot quantities of 1000 for $5 or $6 per unit (prices based on my recollection of vendor tables at the IEEE Magnetics Conference in Hamburg Germany).
 * 2. Increase the extendibility of the R/W head's bit and track densities for future floppy disk drives at virtually no increase in the manufacturing cost /unit (due to ferrite/glass R/W gap's resistance to tribological erosion in direct contact with the floppy disk media, and the nearly infinitely sizing of the magnetic core widths).

The licensed "IGAR" patent was used by most, if not all major (and minor) floppy drive vendors in PC compatible computers providing a very low cost R/W disk drive, making the home computer (PC market) volumes possible in that time-frame. Do not confuse the R/W Head (transducer) with the suspension or arm assembly that carries the R/W head. The extremely small size of the IGAR head (by virtue of ferrite's magnetic properties) made it possible to package the these transducers in the subsequent 5.25" and 3.5" floppy drives on gimbeled suspensions (for double sided recording).

71.84.13.113 (talk) 06:46, 6 October 2014 (UTC) William W. Childers, co-inventor of the IGAR Head


 * Can you provide a source for the above? Rwessel (talk) 07:16, 6 October 2014 (UTC)


 * Note that Pugh in "IBM's 360 And Early 370 Systems" p.515 states, "..the first floppy disk for read-write operation, the Igar (IBM 33FD), shipped to customers beginning in 1973." Pugh (p.517) also noted that IBM started development of a R/W FDD under the code name Figaro and it was renamed Igar - fIGARo, without the fAT and oVERHEAD (p517).  Pugh also details the many changes as the 23FD evolved into the 33FD without explicit mention of the head technologies of the above patent (P517-521).  FWIW, most veterans of that era use "Igar" to describe the drive which no doubt included an "Igar head."    Tom94022 (talk) 16:50, 6 October 2014 (UTC)

Early 3.5 inch FDD Differences
I reverted a paragraph "early" 3.5-inch FDDs based upon a 2002 article focused on Macintosh usage since a source dated 2002 is untimely with regard to early 1980 events and I know that the article's statement that Sony invented the Microfloppy is incorrect. The Microfloppy Industry Consortium (MIC) defined the "Microfloppy" and one of the changes required to the original Sony design was a self closing shutter. AFAIK the original Sony design did not require the shutter to be manually opened. I think most of what the 2002 article describes is just the differences between the original Sony design, used by very few, e.g. HP, and the design promulgated by the MIC and then adopted by everyone including Sony. I'm traveling so I won't have much to to research this until April so I'd appreciate any help from other editors and some forbearance until I get back to my source documents. Tom94022 (talk) 22:45, 1 March 2015 (UTC)


 * That's absolutely fair enough... I just remembered that I had used a kind of 3.5-inch diskette that shipped with an Apricot system I inherited (ca. 1994) that had been purchased in 1984 and it had been the only time I'd ever seen these unusual latching-shutter disks... I figured since there was no other mention of them in the various Wikipedia entries that they'd been overlooked... I don't believe I still have these examples (although mathematically the probability is non-zero) so I spent half an hour trying to find references and examples on the web. Certainly, the Apricot systems the disks came with were happy using non-latching disks bought in the early nineties, and didn't latch them in the open position themselves. I felt that this early, rarely seen version of the medium warranted a mention here, although I'm happy to accept your reversion. I would like to see it mentioned in some form though as it is an interesting curiosity. Happy to collaborate on this.Shalroth (talk) 20:42, 6 March 2015 (UTC)


 * Great, I agree that the article should have something about early variants. As soon as I get back to my files I will update this talk and perhaps the article.  U might want to see what is available from the MIC and from ANSI sources.  As I recall the Sony FDD was opposed by the American manufacturers who organized the MIC as a way to slow the Sony penetration of their then dominant 5.25 inch market.  The MIC spec was then presented to ANSI (X3B6 as I recall) who adopted it forcing Sony to redesign to meet what became the defacto requirement.  The shutter change was one of several required; as I recall the original Sony drive opened and close the shutter, it just wasn't spring loaded so if the drive failed to close or a user opened it in curiosity it remained open.  Finding reliable sources will be a challenge - good hunting  Tom94022 (talk) 02:07, 7 March 2015 (UTC)
 * Note I will have limited connectivity for the next two weeks so don't take my absence as meaningful. Tom94022 (talk) 02:12, 7 March 2015 (UTC)
 * The the media for the first (November 1981) Sony 3.5 FDD, the Sony Model OA-D30V did have a manual shutter. A second generation, OA-D31V may also have had one.  There are multiple sources that say that one of the several improvements instituted by the MIC was a change to an automatically closing shutter ("Sollman was buoyed by Sony's decision to incorporate an automatic shutter into its design, removing one of the differences between its design and the design of the 21-company committee," George Sollman, VP Marketing, Shugart Associates, circa November 1982).  This first Sony product was sold to a number of companies; however the MIC design became the standard we know today as the Microfloppy.  Sony shipped its first MIC compatible, OA-D32V in November 1983, shortly after shipments by Shugart and Tandon (according to Disk/Trend).  I think I have enough to add info about the variant into the article.  Comment?  Tom94022 (talk) 17:44, 30 March 2015 (UTC)
 * The media (OM-D30V) has a manual shutter, but the drive OA-D30V had the capability to open the shutter on auto shutter disks (the OA-D31V also has this capability as well). You can see a video of this in action here:  https://www.youtube.com/watch?v=Sz8FBE7Ka7s.  (Mark)  — Preceding unsigned comment added by 32.213.142.72 (talk) 19:43, 1 December 2018 (UTC)

I actually have some of those early latching floppies sold by Apricot, and I've posted pictures for them here: [] - please feel free to use any of these pictures for Wikipedia.(CC BY-SA is fine). James a craig (talk) 09:16, 28 August 2015 (UTC)
 * Nice photos and article; if it were more complete we could link to it from this Wikipedia article. Otherwise u might have to contribute the photos to Wikimedia before we could use them here.  Tom94022 (talk) 18:34, 28 August 2015 (UTC)

Memorex 650 vs 651
The Memorex 650 was announced in early 1972 with its own 1972 specification which was different than the 1973 651 specification. The 651 was introduced in 1973 as an "An enhanced version of the Memorex 650, ...". Jim Porter's 2005 remark is not reliable given these contemperaneous reliable sources; he likely confused the two models. Unfortunately Porter is deceased so he can't correct the record. Tom94022 (talk) 06:39, 22 April 2015 (UTC)

Revert of good faith edits by 71.165.113.100
71.165.113.100 made four goof faith edits, which I have reverted. I’ve place the summary here because of the length limitations of the edit summary.

The first sneakernets, broadly defined (as in Sneakernet), were undoubtedly tape or card based, so while people exchanging 8” floppies may well have been the first form of that for *floppies*, it was hardly new. Sneakernets are mentioned in the main article.

The conversion of various fractional-inch sizes to decimal ones is inappropriate – common usage, and the other usage in this, and the other floppy disk related articles has settled on the fractional sizes.

The additional about cost and availability would need better references, and in the case of the 2.88MB floppies, are clearly secondary considerations – that was, as noted in the article, was clearly obsolete when it shipped (at least in hindsight), and is unlikely to have become popular even with a near zero cost increment. Media and hardware expense form a vicious circle with lack of demand leading to high prices. Rwessel (talk) 23:09, 30 May 2015 (UTC)

The 5 ¼-inch Napkin Urban Legend
There is no reliable evidence of Porter's napkin version of the genesis of the 5¼-inch FDD. Porter wasn't at Wang and there is no record of Adkinson affirming this story. Personally he has told me it is not true. Massaro who was there in the oral history denies the story when Porter asks him about it and gives the story used in the article; that is he and Adkinson mocked up the first while driving from Boston to Herkimer, NY. It is highly unlike Dr. Wang was ever in any bar with Massaro and Atkinson. The story is simply unreliable, it is also not true but that is OR. Tom94022 (talk) 06:07, 30 September 2015 (UTC)
 * I'm sorry, do you have this in some sort of V source for that? The fact that this rumor is well known is unassailable. Do you disagree that Computerworld mentioned it? Do you disagree that it is widely mentioned? Maury Markowitz (talk) 11:22, 30 September 2015 (UTC)
 * There is no dispute that Massaro, Adkinson and Wang met in Boston circa January 1976 and that Porter wasn't there. There is no published statement directly attributable to Adkinson, the napkin legend is all second hand, mainly spread by Porter and it is unreliable given Massaro's statements in the published oral history.  That should be verifiable and sufficient to not publish this legend in Wikipedia.
 * By way of backround, the Computer History Museum for its Revolution FDD Exhibit originally included the legend, but based upon my research for them as a member of their Storage SIG the legend was not included. In my files is a bunch of unpublished material (including material from Massaro and Adkinson) that clearly debunks the legend. BTW, it was Massaro who made the correction to Wikipedia in 2009 to remove this legend.  It is not uncommon for urban legends to be widely repeated, that doesn't make this one usable for Wikipedia given this background.  Tom94022 (talk) 16:42, 30 September 2015 (UTC)
 * This legend does exit and is easily found online. That is the benchmark for inclusion on the Wiki.
 * I would love to add a direct denial of the story by any of the people involved, but so far you have failed to provide any V source for such. Massaro does not deny it, that's WP: SYN.
 * I'm all for correcting history, but rather dead set against ignoring it. Maury Markowitz (talk) 17:00, 30 September 2015 (UTC)
 * The benchmakrk is a reliable source; multiple repetitions of an urban legend do not make a reliable source. Massaro states:
 * "I was there the day that Dr Wang requested that product. Jimmy Adkisson and I  were back in Wang Labs"
 * and in responding to Porter's assertion that Adkisson has a different story about a bar and napkin, says
 * "Yeah. Well, anyway, the thing we all agree on is the catalyst was Dr. Wang"
 * which sounds to me like a dissent from the bar/napkin story by one of the only three people there. He then goes on to give his version of the Wang meeting.  There is no public affirmation by of the legend by Adkisson so there is no reliable source for the legend.  I suppose if u want to put it in as an unconfirmed urban legend I can't object, but u shouldn't take out the Massaro version which is pubic and from a reliable source.
 * BTW, a cocktail napkin doesn't have the dimensions of a 5¼-in FD Tom94022 (talk) 19:51, 30 September 2015 (UTC)
 * And shirt pockets are considerably smaller than 5 inches, the largest of my dozen or so examples is a maximum of four inches. So the story about the shirt pocket size is wrong too. So, then, according to the logic above, we should discount anything Massaro said too? Maury Markowitz (talk) 13:03, 2 October 2015 (UTC)

The benchmark for RS is an RS and that has been provided - Byte and Computerworld are RS by any definition. Your reading of Massaro's comment is SYN, and I read it to mean something else entirely. So it's going back in until you provide that information. Don't worry, "u"'ll like the result. Maury Markowitz (talk) 12:30, 2 October 2015 (UTC)


 * I don't see how you can interpret Massaro's comments as anything but disputing the Adkisson story as alleged by Porter. Since this occurs after the Byte and Computerworld articles they are on their face unreliable since they had no chance to check and possibly correct their stories.  Tom94022 (talk) 17:05, 2 October 2015 (UTC)


 * I interpret Massaro's comment as agreeing that Adkisson said that. This story is so widespread I found it in a advertisement. I have now provided two RV cites, it is beyond argument that this story is out there - even you don't debate that. If you continue RVing I'll be taking it to dispute resolution. Maury Markowitz (talk) 13:59, 3 October 2015 (UTC)


 * Having been at the oral history I can tell u that is not what Massaro meant and I would also point out that the 2009 correction was by Massaro. Regardless, the most reliable source is still the CHM oral history and its version should be first.  Please stop asserting this urban legend as first.  Tom94022 (talk) 22:01, 3 October 2015 (UTC)
 * I just re-read the oral history, and Massero seems quite clear that the size was derived from a tape drive form factor, and not a cocktail napkin. The cocktail napkin thing has been repeated many times, but clearly loses considerable weight if one of the principles disputes it.  Rwessel (talk) 22:39, 3 October 2015 (UTC)
 * Massero does not once state that in the reference. I see Sollman state it, but the only time Massero even talks about it is to deny it, "I'll let you rewrite history. Go ahead." and " ...I'm telling you, Jimmy Adkisson and I cut out a cardboard mockup of a diskette..." The dialog on page 8 and 9 has him disagree with Sollman at every turn. If you find a passage that suggests otherwise, by all means, point it out. Moreover, on page 8, Dalziel says "I vote with George", also refuting Massero. That's two people directly refuting Massero's version of the story right to his face. Maury Markowitz (talk) 13:31, 4 October 2015 (UTC)
 * There really is no dispute, Sollman and others are talking about the final size of the diskette while Massaro is talking about a cardboard markup which may or may not have been presented to Wang. No one disputes Massaro's statement that he disagrees with everything about the story attributed to Adkisson by Porter other than Wang's significance in the decision to proceed with the project.
 * This issue was raised in 2009 and the consensus then was to drop the urban legend about the bar meeting and cocktail napkin. It has remained out of the article until now so I suggest Maury Markowitz needs to gain a consensus that is remain in.  Note I left it in in my last edit so as to avoid an edit war, but changed the emphasis to reflect its uncertain status.  My recommendation is to remove it as was done in 2009. Tom94022 (talk) 16:53, 4 October 2015 (UTC)
 * One more point about the so-called reliable sources for the alleged Wang meeting, the second two are just Porter telling his story and the first one (Byte v14) does not discuss a meeting a Wang. Unfortunately the entire article in Byte is not visible but I suspect the customer was not Wang. Thus, use of Byte is impermissible synthesis. Tom94022 (talk) 20:58, 4 October 2015 (UTC)


 * On p.7, he says "So literally we designed the 5 1/4" floppy drive in terms of the overall design, what it should look like, in a car driving up to Herkimer, New York to visit Mohawk Data Systems, and we stopped at a stationery store and we got some cardboard and so forth and so on because we're trying to figure out what size diskette this should be. And we ended up with 5 1/4" and it's real simple, the reason why it was 5 1/4". 5 1/4 was the largest -- was the smallest diskette that you could make that would not fit in your pocket." On p.10 he the dialog is: "Porter: Jimmy said that you guys got together with the guys at Wang in a dark bar one night and, after a discussion, you decided on the size of what the smaller diskette should be and there was a cocktail napkin on the bar which was 5 1/4" square napkin . That's Jimmy's story. / Massaro: Yeah. Well, anyway, the thing we all agree on is the catalyst was Dr. Wang."  He's clearly disagreeing with the cocktail napkin version.  The subjects are clearly disagreeing about some of the history.  Perhaps the best solution is to omit any mention of how it was designed.  It is at best a bit of trivia anyway.  Rwessel (talk) 02:43, 5 October 2015 (UTC)

I've provided two independent RS references clearly and directly stating that the napkin is the origin of size of the floppy. here is another from CMU, and even the CHM says it too. You have provided only a single reference, a CHM talk that also references the napkin, and doesn't specifically say its wrong. Let me know when you have a second independent source for his version of events. How's that sound? Maury Markowitz (talk) 22:44, 4 October 2015 (UTC)
 * See:
 * Note a Google search finds an earlier version of this oral history with out the Editor's note. This should end any question about a bar meeting with Dr. Wang where the size of the FD was based upon a bar napkin.  BTW, bar (cocktail) napkins are not today 5¼-inch by 5¼-inch (see, e.g., napkins) but who knows what they were in 1976 (I tried to find out but was unsucessful).  Tom94022 (talk) 17:36, 28 April 2017 (UTC)
 * The "Oral History Panel on 5.25 and 3.5 inch Floppy Drives" at the Computer History Museum show the original participants in the floppy design have different opinions on how the 5.25 inch size came about. The article should report the dispute on the napkin story.
 * The mini floppy was designed to replace the Wang cassette tape drives. Here is a 1977 photo of the Wang PCS-II with mini diskette. This system previously had a cassette drive next to the CRT. It is very likely the width of two drives needed to fit on top of the system. The drive motors were DC powered so they would not affect the CRT. -- SWTPC6800 (talk) 02:10, 5 October 2015 (UTC))
 * Is that a cassette or DC300? I ask because the DC300 is 5.875 in by 3.875, so the 5.25 drive would need to be designed to fit into that hole. I know that Tek used both types of tape, and their TT120-based cassette was HUGE, so it could be either one. Maury Markowitz (talk) 11:48, 5 October 2015 (UTC)
 * I really don't think there is any dispute but I have the advantage of both having sat in on the 2005 oral history and then researching this for the museum in 2009 so this is in part OR but it does put the oral history comments in context.
 * In 1975 many Shugart customers wanted a smaller and cheaper FD; Wang at that time was the largest customer.
 * One potential customer was Lanier on Long Island, NY, who first proposed to Adkisson a smaller drive with the medium size about that of a cocktail napkin. Adkisson took the concept to Shugart HQ
 * Massaro and Adkinson visited Wang in January 1976 to discuss future products where Wang (at the labs not in a bar) expressed a need for an FD alternative to the cassette recorder contemplated for a new product. They may have presented a mock up Wang (Adkisson) or built a mock up on the way to Herkimer, in both cases the size is unknown other than it was smaller than an 8-inch.  However, they both agree that Wang desired such a product.
 * Engineering was tasked with coming up with the actual dimensions of the diskette and drive based upon fitting within the existing cassette drive form factor (today of unknown dimenstions) they came up with the proposed dimensions for the SA400 FD and it's SA-104 5¼-inch diskette. Note the width of the SA400 is 5.75-inches not too different than the one DC300 cited above and the diskette is ½-inch smaller than the drive allowing for ¼-inch space on each side for the diskette receiver and tolerances.
 * According to his trip report Sollman visited Wang on February 23, 1976 and presented the proposed SA-400 and SA-104 which is the first public showing of the "5.25 in. x 5.25 in." dimension which became the industry standard dimensions. I suppose I can post this document on a website
 * I suggest what we have in the oral history is a semantics issue where sometimes the participants are using the same words to variously mean the concept of a smaller drive/medium, the first mock-up of the medium and/or the media's final dimensions. There is no reliable support for Porter's urban legend about Wang and the cocktail napkin in a bar. Therefore I suggest it is reasonable for us as editors to sort out these semantics and succinctly describe the genesis without including non-existing and not particularly relevant controversies such as cocktail napkins, various mock-ups, etc. Tom94022 (talk) 20:28, 6 October 2015 (UTC)

There's a rumor that there is this guy called God who created the universe in seven days. Lots of people talk about this, they even have a best selling book on the topic. That such a rumor exists and is in the historical record is not open to debate.

There is another rumor that the size of a floppy disk is about what it is because of a cocktail napkin in a bar. Its so widespread that they even used it in 1980s advertising. That such a rumor exists and is in the historical record is not open to debate.

Now I leave to you the task of either expunging all the articles on religious matters from the Wiki, or explaining why this particular topic is somehow different. But don't actually bother, I'm done debating this issue, and if you feel so strongly about this, call a formal vote. Maury Markowitz (talk) 18:25, 28 April 2017 (UTC)


 * I hope you would agree that there is a differnce between beliefs as in God and urban legends such as the one discussed herein. The Shugart folks that invented the FD deny the urban legend that "the size of a floppy disk is about what it is because of a cocktail napkin in a bar." No vote is necessary given there are now reliable sources as to how the 5¼-inch FD was sized.  BTW, the Shugart folks agree it was "inspired" by a cocktail napkin (as the CHM says) but no bar and no meeting with Dr Wang at a bar.  When I get around to it I will add the genesis of the 5¼-inch FDD to the article along with the fact that the bar and Dr Wang are an urban legend.  08:26, 29 April 2017 (UTC)

Dr Nakamatsu,Redux
An IP has resurected the unsubstatiated claims of Dr Nakamatsu that he invented the Floppy Disk. This has been discussed before and the consensus was that Dr Nakamatsu claims were unsupported by any evidence, some history is at this search. My recollection is that the Japanese patent claimed as his FD invention has nothing to do with the FD patent issued to IBM's Thompson et al where in at least one key element is the "wipe" used to control contamination. Unless the IP has some new reliable source for supporting Dr Nakamatsu's claim I suggest the article best remain as it is. Tom94022 (talk) 03:02, 18 April 2017 (UTC)

I took a look again at his patent, particuarly the images which disclose nothing like the FD, starting with its recording medium is a rectangle, the tracks are not circular and there is no wipe. There is nothing this patent that anticiates or makes obvious the FD. Tom94022 (talk) 03:29, 18 April 2017 (UTC)


 * I reinstated "known to the media media as", but without the doubled "media". I wasn't sure whether to fix it as Work on the drive for what became known to the media as "the world's first" floppy disk drive. or to Work on the drive for the world's first floppy disk drive., but neither "media" nor the quotes made sense without the "known to the". Shmuel (Seymour J.) Metz Username:Chatul (talk) 16:36, 19 April 2017 (UTC)


 * I think it now reads better and correctly. The point being the first drive an media activity started under Noble never saw the light of day; it evolved into what we now know to be the FD and FDD, subject to two patents, Thompson et al and Wartner et al respectively.  Tom94022 (talk) 00:32, 20 April 2017 (UTC)


 * It's still got the scare quotes. The phrase shouldn't be quoted unless you are attributing it to someone. Shmuel (Seymour J.) Metz Username:Chatul (talk) 15:41, 20 April 2017 (UTC)


 * Sorry I don't see any quotes in the lede, scary or not :-) Tom94022 (talk) 22:54, 20 April 2017 (UTC)

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Most 8 inch disks were not hard sectored
By the mid to late 1970's, the IBM 3740 key to disk stations used soft (not hard) sectored diskettes, at least not the ones I worked with, which may have been later models as I was working on in the mid to late 1970's on utilities to transfer / translate data on 8 inch diskettes between IBM (EBCDIC) and non IBM (ASCII) systems, one of which was a CP/M system (Pertec PCC 2000). That CP/M system and other CP/M systems (for example ATR8000, some S100 bus systems, ...) also used soft sectored diskettes. Rcgldr (talk) 10:38, 3 April 2019 (UTC)
 * Possibly true and worth noting in the 8-inch section that Igar and/or Diskette 1 were soft sectored if an RS can be found. As I recall the drives could be set in either index or sector mode if the medium had hard sectors but if the medium didn't the drive had to be in soft sector mode (to control/measure rpms) as well as the controller.  I do recall some hard sectored 8-inch drive applications, Wang maybe, so at most we can say is something like the article already says in the 5¼-inch section, i.e both were found in 8-inch system applications. Tom94022 (talk) 16:51, 3 April 2019 (UTC)
 * I don't recall any drives with dynamic speed control, drives were manually adjusted using a utility monitoring the index hole. The index hole was also used to trigger the start of a format command with most controllers, but not used for read or write operations. In the case of CP/M systems, by the time of double density drives and media, sector sizes varied: 256, 512, or 1024 bytes (max capacity was a bit over 1.4 MB with 9 1024 byte sectors per track), which would render the hard sector holes useless. Rcgldr (talk) 10:20, 9 April 2019 (UTC)
 * I'm not sure dynamic speed control has anything to do with the subject - many 8-inch drives used ac motors which had no speed control but they all did measure speed so as to enable opeation.
 * According to 1982 Disk/Trend Report - FDDs, both single sided and doubled sided 8-inch drives sold on an OEM basis were usually available in either soft or hard sector versions. The report does state that IBM Diskette I had a single index hole (meaning no sector holes) so given IBM's market dominance is it I think it is reasonable to say something about both hard vs soft sectors in the 8-inch section. Tom94022 (talk) 16:11, 9 April 2019 (UTC)
 * I have a pair of full height 8" drives with fairly large AC motors. I also have an 8" IBM Diskette (I'll post an image later if interested) and 50+ 8" diskettes from the CP/M days (the ATR8000 still worked last time I tried it). The index hole location is different for single and double sided diskettes (double sided hole is a bit to the right of the single side hole), but there's no difference between single and double density. The drives have sensors at both hole locations to work with either type of diskette. Rcgldr (talk) 02:00, 11 April 2019 (UTC)
 * Since there is no RS for the claim that most 8-inch floppy disks were hard sectored, I suggest simply removing that statement. Rcgldr (talk) 19:27, 8 May 2019 (UTC)
 * I rearranged the section so I think there is no remaining issue. Tom94022 (talk) 22:17, 8 May 2019 (UTC)
 * Take a look at the IBM 33FD List_of_floppy_disk_formats, released in May 1973. It is soft sectored (not hard sectored), and has 3 different sector sizes and number of sectors per track: 128 x 26 | 256 x 15 | 512 x 8 . Somewhat confusing is the article mentions the SA 800 (released in 1977), before mentioning the IBM 33FD (released in 1973). The SA 800 is soft sectored. The SA 801 is hard sectored, but the manual mentions being able to convert the SA 801 to SA 800 with a jumper, disabling the hard sector output pin (the SA 800 can't be converted to an SA 801, since it doesn't have the sector sensor). SA 800 pdf. I'm still looking for a RS, but going back to 1973, hard sectored floppy disks were rare at the job or school sites I visited. Rcgldr (talk) 10:25, 9 May 2019 (UTC)
 * As best I recall there was only one sensor - the index hole was between two sector holes and the selection was electronic. Tom94022 (talk) 18:40, 9 May 2019 (UTC)
 * Before the SA800 was the SA900. Before the 33FD was the 23FD and a bunch of OEM FDDs (e.g. Calcomop, Memorex, Potter, others?) all hard sectored as best I recall.  The SA900 was offerred in both hard and soft sectored so it could be used in either 33FD mode or prior modes.  As best I can recall a number of system manufacturers used hard sectored FDs, perhaps Wang?  Regardless, I think the paragraph is now correct in ascribing hard sectors to prior to 33FD.  Tom94022 (talk) 18:40, 9 May 2019 (UTC)
 * So "most early floppy" disks means ones made between 1972 and 1973 (release of the 33FD)?. SA900 was soft sectored, SA901 was hard sectored, but both used a 40 or 44? pin connector, as opposed to the 50 pin connector that became the standard for 8 inch drives. Rcgldr (talk) 19:05, 10 May 2019 (UTC)
 * It means those sold in 1972 and 1973 and perhaps later. IBM never sold the 33FD separately. Shugart Associates was not formed until the summer of 1973 and likely didn't ship anything until 1974.  With the announcement of the 3740 all existing and future FDD manufactures started designing for 33FD compatibility and without further research my guess is they didn't ship any volume unitl 1974 or later.  In the meantime the existing OEM customers bought and deployed the existing hard sector designs.  Tom94022 (talk) 22:43, 10 May 2019 (UTC)
 * FWIW, according to Disk/Trend the Shugart 900/901 first shipped circa Sept 1973 and was the first IBM 3740 compatible OEM disk drive sold separately in the market (IBM never sold the 33FD separately). So most if not all FDs shipped to end-users in 1972 and 1973 and perhaps later were likely hard-sectored.  Tom94022 (talk) 23:01, 10 May 2019 (UTC)
 * unindent - 3740 data entry system (mid to late 1973) floppy disks were soft sectored. In the early 1970's, people were still using "cartridge" type single platter 14 inch hard disks enclosed in plastic shells as "removable storage", like the IBM 2310. I don't recall floppy disks becoming popular until CP/M, which was released in 1974, although at that time, it seems that the only platform for CP/M systems were Intel developer systems. I'm not sure which there were more of back in 1972 through 1974, 3740 data entry systems, or pre CP/M systems that used floppy drives, or those early Intel developer systems. CP/M seemed to take off around 1975, but by then, almost all of the CP/M systems used soft sectored media. Rcgldr (talk) 09:38, 11 May 2019 (UTC)
 * Nothing of what u say rebuts the statement that "most if not all FDs shipped to end-users in 1972 and 1973 and perhaps later were likely hard-sectored." Tom94022 (talk) 06:47, 12 May 2019 (UTC)
 * The issue I'm having is I can't find a reliable source to cite what the relative popularity of hard versus soft sectored 8 inch floppy disks versus year, and I'm wondering why such a statement is in the article if there is no reliable source for it. I'm finding also finding conflicting information, such as stating some versions of the IBM 3740 data entry systems were made as early as 1971 (perhaps available at data centers?). Most of these articles are based on someone's personal memory as opposed to a copy of some document from the company making such systems. The other issue is that most of the articles about hard sectored floppies mention either 8 or 32 sectors per track, while sometime prior to 1975, 26 x 128 byte sectors became fairly common for single density floppy disks (33FD also supported 15 x 256 or 8 x 512), and none of these were hard sectored. Rcgldr (talk) 15:34, 12 May 2019 (UTC)
 * There is no relative issue. Prior to the 33FD all FDDs starting with the 23FD beginning in 1969 and then the OEMs were hard sectored (starting with the Memorex 650 shipping first on its SCUs). The first key to FDD from vendors using OEM FDDs such as Wang used hard sectored FDDs.  So the current article, "most early" is supported by RSes.  Soft sector was techincally more difficult (at least until chip controllers) so there were many hard sector implementations and I'm pretty sure all 8 inch FDD OEMs had dual version models.  So although it is likely that soft sector dominated sometime after 1973 there is no available RS to establish a change over.  There was a media report published but it doesn't seem to be available on line.  Tom94022 (talk) 18:34, 12 May 2019 (UTC)
 * The article could mention the dates or clarify what is meant by "most early". 23FD compatible floppy disks had the sector sensor hole on the outside part of the diskette. I don't know how long these remained popular before the switch to having the index/sector sensor hole inside of the data tracks. I'm not aware of any drives that ever supported both inner and outer index/sector holes. There were hard sectored floppy disks that used the inside hole, but I don't know how popular these were. From the articles I've found, by around 1974, with the 33FD, SA 900, Intel development systems, and CP/M, most of the 8 inch media was soft sectored. Rcgldr (talk)
 * How about something along the lines of prior to the introduction of the IBM Diskette 1 in 1973. You also raise and interesting point about inner versus outer sector/index holes but I'm not sure it is worth including in the article.  Tom94022 (talk) 19:02, 14 May 2019 (UTC)
 * "... Diskette 1" - that should be good enough. The change from outer hole to inner hole was a significant change. Also the outer hole floppy disks were only 8 sectors per track. I'm wondering about the SA 901 and SA 801 drives, as they mention 32 sectors per track with hard sectored floppy disks, while the IBM was using a max of 26 128 byte sectors per track (it also had 15 256 byte sectors or 8 512 byte sectors per track). Rcgldr (talk) 20:57, 16 May 2019 (UTC)

A Commons file used on this page has been nominated for deletion
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 * Fileware-floppy.jpg

Citation for their use was declining?
The lead states Floppy disks remained a popular medium for nearly 40 years, but their use was declining by the late 1990s., but the citation refers to a drop in prices, not to a drop in sales. Does anybody have a correct date and citation for the drop in units sold? Shmuel (Seymour J.) Metz Username:Chatul (talk) 16:43, 9 July 2020 (UTC)
 * See new edit and citation Tom94022 (talk) 00:40, 10 July 2020 (UTC)

Multiple citation with different page ranges - use sfn?
During a recent edit I noticed that there are multiple references to Pugh with different page ranges. I believe that it would be better either to move the page numbers to rp templates or to use sfn with wikilinked loc and pages, moving the citations either after the reflist or to a new section with formatting like foo (above posted by Chatul 08:25, 6 June 2021‎)
 * Pugh 360


 * that makes sense. There are only three such references, why don't you just make the changes - you were 1/3 of the way there above? :-) Tom94022 (talk) 22:08, 12 June 2021 (UTC)
 * You removed one; I've coalesced the other two using rp, since both refer to the same chapter. --Shmuel (Seymour J.) Metz Username:Chatul (talk) 07:08, 13 June 2021 (UTC)

Single access mechanism for double drive
The DEC Rainbow 100 had two floppy drives but only a single R/W head assembly located between two single sided disks. Does it belong in the floppy article? --Shmuel (Seymour J.) Metz Username:Chatul (talk) 16:36, 22 February 2022 (UTC)
 * I suggest no, as WP:undue. This article is mainly about the disk and less about the drive.  There are all sorts of drive mechanism differences that in the context of this article are more significant that the Rainbow FD, e.g. band-capstan vs leadscrew and later servomechanisms of some sort.  Tom94022 (talk) 18:29, 22 February 2022 (UTC)