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Talk:Digital Equipment Corporation

Reason for bankruptcy
Didn't DEC go bankrupt due to its own inept sales force pushing Pentium machines over the AlphaPC? I once heard someone complain that DEC was a company you couldn't give money away to (his words). — Preceding unsigned comment added by Ark~enwiki (talk • contribs) 19:33, 10 July 2022 (UTC)

Why did DEC fall?
One reason that DEC fell was its inability to hold its senior executives accountable for financial performance after the abolition of the Product Lines in the early 1980's. Ken Olsen was very proud of creating the Product Lines after the problems with the PDP-6 that almost killed the company in the early 1960's.  Each Product Line had responsibility for a computer system (PDP-8,9/15, 11, DEC-10's) and the GM/Managers were held accountable for profit, revenue growth, and to a lesser extent customer satisfaction.

It knew early in the mid 1980's that it needed to cut its cost structure by about 1/3 if it was to compete in the 1990's. However, Ken Olsen absolutely forbid layoffs, so little happened until the situation became so desparate that he had to relent.

Instead it attempted to grow its way out of the problem through a massive re-deployment of resources to the field that wasted hundreds of millions of dollars.

Another major reason the company failed was that it did not adjust to the restructuring of the computer industry from full service highly integrated systems suppliers to areas of horizontal expertise - Intel for micros, Oracle for database, etc. DEC had the technologies to compete in many areas but the corporate strategy was to only sell systems.

It was a great company that could not adjust to a dramatically changing business environment that meant tightening its belt and changing what it sold and how it sold... until it was too late. —The preceding unsigned comment was added by 69.182.238.233 (talk • contribs) 20:45, January 14, 2006.

 * When I worked at DEC in the mid-80s, there was an article in a business magazine (Forbes? Fortune?) about how DEC was trying to sell computers to farmers with a slogan that described the company as the "Second-largest computer company in the world" - to which farmers would ask, "so what's the biggest computer company?" I think it's funny that the article repeats this mistake: "At its peak in the late 1980s, Digital was the second-largest computer company in the world, with over 100,000 employees."129.55.27.4 — Preceding undated comment added 14:59, 26 January 2006 (UTC)

 * One might argue that DEC failed because "cheap" always trumps "good". DEC products were good, PCs were cheap, the rest is history. (One might also wryly observe that this was exactly how DEC built its business against competitors like IBM, but I'd like to believe that many DEC products were both cheap and good.)
 * Atlant 15:10, 26 January 2006 (UTC)

 * Agreed. DEC Failed to embrace microprocesor based systems early on. In the late 70's early 80's they had superior operating system software for small computers and could have blown IBM away had they introduced their own uP based system with their software at the time the PC was introduced. DEC's products were 'cheap' and 'good' compared to commercial mainframes at the time, but the PC was a game changer.  Produced for the mass market, it was very cheap but its software was not very good. From what I've read Ken Olson would not support those in the company that wanted to bring to market a low cost uP based system.  His lack of vision is what killed a top notch company.71.38.174.228 (talk) 14:55, 12 November 2009 (UTC)

 * A major shortcoming of the product line structure was that it created too much internal competition wasting money, resources, and product development. Too much time and energy was wasted getting "buy in" as each product group would only focus on thier own self interests. — Preceding unsigned comment added by 64.69.103.254 (talk) 15:02, 13 April 2007 (UTC)

 * I can tell you why they fell into disfavor at one NASA center: they were too expensive for what they were providing. The fact they could be heavily hardware-configured in days when hardware was very expensive indeed was a great advantage, but it was an advantage that whittled away when cheaper "general purpose" computers came out, because then buyers could afford to buy components which they really were not going to use. Also, of course managers loved the idea that whole computers could be "plug compatible" the way employees were held to be. I.e., if something goes wrong with a project, a manager can shuffled in or out computer equipment -- putting a lot less emphasis on long-term planning. (And...hiding management miscalculations.)
 * The incredible cost of configuring digital computers is shown by a statement, after giving their paper at an AI conference, by one of the DEC speakers that the AI configuration program cost $1,000,000 a year to maintain. Not to write, just to maintain. 24.130.13.180 (talk) 09:33, 1 September 2008 (UTC)

Well, let me tell you a story which says why DEC lost one customer. In the mid-1980s, the company I was then working for had bought 20 PDP 11/73s, delivered in pairs over ten months. We also got a tape with the operating system (RSTS/E) and other software with the first pair of systems. Unbeknownst to us, halfway through the period, there was a hardware upgrade in the CPU, which was subtly incompatible with the version of RSTS we had. After we had been running for well over a year, I was able to track down some errors that we were having on some machines to this incompatibility. The old hardware was no longer available, and we were told that we would need to get ten new CPU boards and a new software tape to make all the hardware the same and to have a good version of the OS. The kicker was that DEC insisted that we pay $8000 for each board and $2500 for the software upgrade, for a total of $82,500. We maintained that since the problem was caused by them, they should eat the cost. We might have come to some arrangement for splitting the cost, but they were adamant. We had to pay it all. They would not come down even on the price of the tape. Since even the properly working systems were slow and the application software difficult to maintain, we determined that we would start over again on this application, using a proper DBMS (the old one used ISAM files), C (the old one used BASIC+2), and UNIX and faster hardware. However, at the conclusion of the meeting where this was decided, the CIO stated "Digital Equipment Corporation will not be invited to bid on this contract." Thus, DEC lost out on a contract worth over a million because they insisted that we pay $82,500 for a problem that was really their fault. Jhobson1 (talk) 13:34, 12 April 2011 (UTC)

 * Why Did DEC fall? Why did Apple Succeed? Marketing!!! As a DEC OEM I fought long bitter and costly battles trying to get DEC to understand that "digital" was a kind of watch in the minds of every single prospective Customer I came in contact with. My greatest sales hurdle - building up the digital image in the minds of my prospective customers. DEC had promised me for years it was going to enter into cooperative marketing agreements to help cover my marketing costs and promote the digital name.  They never fulfilled those promises.  So we started looking at the emerging microcomputer as a means of controlling our costs.  And in the process we ported our software to several platforms including CP/M MP/M DOS and others.  When IBM introduced the PC we were ready.  It took us about a week to port our software to the PC - Of course everyone knew who IBM was - we didn't have to sell IBM.  So it was "Good bye" to DEC & Ken Olsen's promises and Hello to IBM. Our PC solutions sold like hot cakes.  — Preceding unsigned comment added by StumpLifter (talk • contribs) 21:20, 1 October 2011 (UTC)

website
The reason I came to this page was because I read (on a web history page) that DEC put up the first commercial website. In this article it says they were amongst the first .com websites. Were there any .com websites before DEC that weren't commercial? I thought if it was one it would be the other as well, but it'd seem strange to refer to the first ever as one of the first... sheridan 03:30, 31 January 2006 (UTC)

Polycenter?
I believe one of the other items DEC divested was their management software known as Polycenter. This software went to Computer Associates. — Preceding unsigned comment added by D9nno (talk • contribs) 22:43, 26 April 2006 (UTC)

 * Yes it was one of the first generation of enterprise management offers in the market. — Preceding unsigned comment added by 86.128.138.176 (talk) 17:31, 25 July 2006 (UTC)

 * While today's SOA gets attention, is it important to note DEC pioneered much of the architecture in todays systems. Much of BEA Systems is based on software developed by DEC. — Preceding unsigned comment added by 64.69.103.254 (talk) 20:10, 12 April 2007 (UTC)

Soviets
Is it worth noting that an 11/782 was seized in 1983 as part of a contraband shipment to the Soviets? --Gadget850 ( Ed) 13:48, 27 May 2006 (UTC)

 * There should be a lot more to say about this. I read that many Soviet bloc computers were modeled on (or clones of) PDP's and Micro-VAXes. Hrcohen (talk) 01:16, 9 October 2008 (UTC)

Intel processors inspired by DEC PDP-8?
Without a citation, I don't buy the idea that any of the early Intel 4-bit or 8-bit microprocessors were "inspired by the PDP-8". There is no significant architectural similarity between the PDP-8 and the 4004, 8008, or 8080. On the other hand, there are very clear similarities between the PDP-8, DG Nova, and HP 2116 family (of which the HP 2100 is a member). If no citation is forthcoming in the near future, I will remove the 4004 and 8080 references in that section. --Brouhaha 18:43, 9 June 2006 (UTC)

 * That also leads to some questionable assertions in the next sentence: "Machines based on the PDP-8 can be characterized by a small number of accumulators (such as AX or BX) rather than a series of regular registers (such as R1-R8) like the PowerPC and PDP-11, so it might be said that it was the descendents of the PDP-8, not the later PDP-11, that inherited the dominant processor status of the 2000s." If the 4004 and 8080 don't resemble the PDP-8 that closely, than the 8080's x86 descendents can't be said to descend from the PDP-8 either.
 * The PDP-11 and its successor, the VAX, were CISC processors, while most modern processors are RISC-based. The difference between CISC and RISC designs probably accounts for more architectural differences between the PDP-11 and today's processors than the differences between the PDP-8 and PDP-11 do. -- CWesling 01:17, 23 June 2006 (UTC)

 * I don't buy it, either. The PDP-8 was, at least from the point of view of a programmer, a beautiful, clean, economical design. I did quite a lot of programming in PDP-1 assembly language and LINC assembly language, both considerably richer in instructions than the PDP-8. Yet the PDP-8 seemed to be just as expressive and easy to program.
 * For several years, I did quite a lot of programming about equally divided between the PDP-8 and the PDP-11. It always astonished me how easy the PDP-8 was to program, and how little you seemed to be cramped by the seemingly severe limitations (only six addressable instructions). When I first saw the PDP-11 instruction set I thought I had died and gone to heaven. Well, when I actually started writing code, sure, the PDP-11 was nicer than the PDP-8, but not nearly as much nicer as I expected. Who'd have thought that eight silly little autoincrementing memory locations could be at least 3/4 as effective as real index registers? And I could swear that it always took significantly more core to write the same program on a PDP-11 as on a PDP-8.
 * In contrast, virtually all the microprocessors were ugly, asymmetrical, ad hoc monstrosities. No doubt it all had to do with how they could run the microscopic data paths on a plane, or whatever. The Motorola 68000 does "feel" a little like a PDP-11, but the 8080 and the 6502 never felt the slightest bit like a PDP-8 to me. Dpbsmith (talk) 01:36, 23 June 2006 (UTC)

 * dpbsmith, see orthogonal instruction set for an explanation of why your PDP-11 programs always seemed bigger than your PDP-8 programs. It's the nature of the beast that a highly-orthogonal instruction set (such as the PDP-11's) is always far less bit-efficient than a non-orthonal instruction set (such as the PDP-8's). (And I say this as an experienced assembly-language programmer on both systems.) Both systems were joys to program, though, compared to the baroque 8080 and x86 architectures.
 * Atlant 12:03, 23 June 2006 (UTC)

VMS++ = WNT
The article discusses how one can get the acronym "W/NT" by incrementing each letter in "VMS". Someone just edited in "Cutler later verified this."

AFAIK, Cutler has never actually made any affirmative statement such as "Yes, I did that intentionally." Instead, he's always said something coy like "Did you just notice that?". (That is, he makes it clear that it was deliberate while not actually saying so.)

Have I got this right?

If so, we should edit the article.

Atlant 16:28, 14 June 2006 (UTC)

 * That's how it looked to me, too, when I Googled for this. So yes, we should probably reword that a little. -- CWesling 23:21, 16 June 2006 (UTC)

Microprocessors influenced by PDP-8?
I still don't buy it. "Machines based on the PDP-8 can be characterized by a small number of accumulators?" No, this is hardly a defining characteristic that makes an architecture PDP-8-like. Broadly speaking, small numbers of accumulators (and small numbers of registers with somewhat specialized, asymmetrical functions) are found in any situation in which registers aren't cheap. Many, many early machines have an "accumulator" and an "accumulator extension," for example. I think the (original) Illiac did. Certainly the PDP-1 did.

The advantages of having many registers are obvious, and they appeared whenever the economic balance for that particular machine permitted it. Conversely, any machine that was cheap or otherwise constrained to have minimal hardware, had a few.

Here are a list of PDP-8-specific characteristics. I'd like to see an architecture match a handful of these before I'd call it "PDP-8-like." I'm not very familiar with the 8080, but I don't think it matches any of them.

 * Absence of any provision in hardware for moving more than one word at a time.
 * Fixed word length.
 * Absence of any hardware support for a stack.
 * Addressing architecture in which the address space is divided into pages, and every addressable instruction can address: directly within the current page; directly within page 0; indirectly within the current page; indirectly within page 0.
 * Absence of any conditional branches; that is, branches that have a target address. All conditional operations are implemented by a single "skip" instruction, which transfers control to either PC+1 or PC+2, on conditions microprogrammed by individual bits within the skip instruction.
 * Extreme economy of instruction set; only six addressable instructions in the case of the PDP-8
 * Word length that is not a power of 2.

Any similaries between microprocessors and the PDP-8--other than the Intersil 6100, of course!--are simply the result of having to solve the same problems, i.e. build a very small computer with limited hardware resources. The PDP-8 and 8080 are no more similar than the PDP-8 and the LINC, or the PDP-8 and the CDC-160.

This is quite different from the situation with respect to, say, Digital operating systems like OS/8 and CP/M and MS-DOS. If you compare these three, you notice things like
 * the strange use of CTRL-Z to mark the end of a text file, particularly strange because according to the ASCII spec "end of medium" is CTRL-Y, not CTRL-Z--probably a mistake on Digital's part, but certainly an idiosyncrasy
 * the use of the CR-LF pair to separate lines
 * the use of file names consisting of a name and an extension separated by a dot
 * the prohibition of space characters within file names

All of these characteristics are shared by OS/8, CP/M, and (early) MS-DOS. None of these characteristics are shared by the Apple ][ DOS 3.3; only one of them is possessed by UNIX.

Thus, I think it is very reasonable to see evidence of Digital OS influence in microcomputer OSes. I do not see any obvious influence of the PDP-8 on microprocessors. Dpbsmith (talk) 20:51, 23 June 2006 (UTC)

P. S. And, regardless of what I or anyone else might have to say, in any case the verifiability and no original research policies mean that anything said on this topic, however well-founded, must be traceable to a published source, not stated without attribution. Dpbsmith (talk) 20:54, 23 June 2006 (UTC)

 * I can assure you that the 8080 and PDP-8 ISPs (and their respective assembly languages) have damned little in common, aside from the facts that they're both (basically) accumulator-oriented load/store architectures.
 * Atlant 22:53, 23 June 2006 (UTC)

 * the use of the CR-LF pair to separate lines
 * I think this was typical for many computer models using dumb printers / terminals / teletypewriters as peripherals in the 1970s. Bold characters and underlines on a printer were the consequence of using CR and overprinting the line. A new line REQUIRED an LF. An LF without a CR continued the text on the next column in the next line. Unix was the first place I encountered the simplification to a single character.
 * the use of file names consisting of a name and an extension separated by a dot
 * This is a convention also followed in Honeywell/GE GCOS and Burroughs MCP mini-computers and I think was incorporated in the conventional ASCII tape format. I would also note that the file name never required an extension. Only that extensions were desirable for several reasons. Hrcohen (talk) 02:00, 9 October 2008 (UTC)

Logo
Just thought I'd add a pointer to a query about the logo here. I'm probably wrong, but anybody know for certain? I'm intrigued now, and don't have any DEC logos handy to leer at. Chris 23:06, 25 July 2006 (UTC)

 * The question of the "dots" verses the "squares" above the "I's" in the red logo is correct.
 * When Bob Palmer took over, the advertising company he hired made the change. They changed it to red and replaced the squares with dots. It was something like DB Neadham agency. They also tried to give DEC a modern feel by playing a fast changing graphic commercial to Lenny Kravitz, Are you gonna go my way. — Preceding unsigned comment added by 71.79.156.222 (talk) 20:35, 13 September 2006 (UTC)

Personal computers
DEC did sell Intel-based Windows compatible computers under their logo (for example, Prioris, Celebris and Venturis product lines). --195.218.145.14 16:59, 7 August 2006 (UTC)

 * DEC's earliest personal computers were 3 separate architectures which lead to some confusion in the marketplace. At that time IBM had gained recognition with their first PC which was Intel-based using Microsoft MS-DOS. The DEC machines were the DEC Profesional based on the PDP-11, DECMate 11 based on the DECmate stand alone Word processor,(similar to the Wangwriter) and the Rainbow. While the IBM PC was gaining large business acceptance, the CPM vs. MS-DOS war was on, and the Rainbow ran both CPM and MS-DOS. DEC seemed to be favoring CPM with the Rainbow, but one of it's major shortcomings was the dual floppy drive used a proprietary format so floppies were not compatible. The DECmate 11 had moderate success as a second generation DECmate Word Processor and the Professional was a disaster. The Professional, based on the PDP-11 (used an LSI-11 CPU)did not have the CPU speed and memory to run PDP-11 software, which was much too expensive for the machine. There were very few applications that would run on the Professional and it died with few sold.
 * DEC soon figured out it was too expensive to manufacture PC's in-house and the second generation Rainbow became just a PC built by Tandy with a Digital brand. By that time WinTel machines became the standard and DEC's PC's were simply branded boxes. — Preceding unsigned comment added by 64.69.103.254 (talk) 20:03, 12 April 2007 (UTC)

450 or 350 million dollar?
"AR&D later sold its investment in Digital for approximately $450 million, certainly the best VC return ever at the time"

http://www.computinghistorymuseum.org/teaching/lectures/pptlectures/10-dec.ppt

"When Doriot sold his share in 1972, it was worth $350,000,000" — Preceding unsigned comment added by CSuarezdelReal (talk • contribs) 20:05, 29 September 2006 (UTC)

The word "Computer" banned.
It is quite interesting that Digital excluded the word "Computer" from their product and brand names, both, as an early way to get funds, so that investor were not afraid to give money to a company that would compete against giant IBM (besides other large computer companies were losing money at that time), and as an early marketing strategy to sell their products to engineering teams in companies where the accountants would reject computers. — Preceding unsigned comment added by 158.116.112.10 (talk) 21:58, 29 September 2006 (UTC)

 * Another version of this story, is that because computers were on one General Services Administration schedule and electronic equipment on another, that it would be easier for government-funded agencies and schools to buy DEC products if they were called something other than computers for purchasing approval. patsw (talk) 18:50, 15 January 2008 (UTC)

Mis-use of ARCHITECT as a verb
I dispute the use of the word 'architect' as a verb in this otherwise well-written article, because it is not a verb. There are plenty of other verbs that can be used in place of 'architecting' and 'architected': construct, design, create, devise, invent, plan, produce. JeffreyMeunier 01:05, 8 October 2006 (UTC)
 * http://en.wiktionary.org/wiki/architect
 * http://www.google.com.au/search?q=define%3A+architect

Writable control store
Atlant removed the information on writable control store, and in the edit summary asked which models supported it. WCS was optional on the 11/780, and standard on the 11/785, 11/750, 8600, 8650, 9000 series, and possibly other models. Microcode development tools were offered as a product for the 11/78x. Most of the later VAX implementations based on VLSI processors had small a on-chip WCS intended to patch microcode bugs. --Brouhaha 00:35, 12 December 2006 (UTC)

T11?
Could someone add information on this chip? Drutt 08:35, 15 May 2007 (UTC)

The word "computer"
In the '70s I was a DEC customer. I was told that the PDP line (Programmable Digital Processor) and the DEC name (Digital Equipment Corporation) avoided the word "computer" because government procurement procedures for "computers" were far more complex than the procedures for almost anything else... by avoiding the word "computer" procurement of DEC products was easier. Could be urban legend?

RobertTaylor21 21:00, 13 June 2007 (UTC)

 * If you can find a cite for this, we can include it in the article --rogerd 21:24, 13 June 2007 (UTC)

 * The original venture captitalists wouldn't fund a company that intended to make computers, believing that there was no room in the market for another competitor to IBM and the "BUNCH". So Digital built "Programmed Data Processors" instead of computers. I think Digital at Work contains this story; I'll try to remember to look.
 * Atlant 13:59, 11 September 2007 (UTC)

Name of the Company
I was hired by Digital just before its acquisition by Compaq, and all the legal documents that we changed over to "Compaq Computer Corporation" had used the name "Digital Equipment Company" [not Corporation]. Digital was indeed a corporation, but the formal name needs to be verified -- especially since "Corporation" is used in the title of the article. --NameThatWorks 18:43, 10 September 2007 (UTC)

 * Well, I'm looking at the "2211 Memory Exerciser Manual", copyright 1962, and it very clearly says "DIGITAL EQUIPMENT CORPORATION". (It's a cool manual because it has the old bi-color "|d|i|g|i|t|a|l|" logo where the d, g, t, and l are white on black rectangles while the i,i, and a are on grey rectangles.) Even earlier than that, I'm holding in my hand a "103" Laboratory Module (yes, the original product) and it says "digital equipment corporation" along with two big, bold "dec" logos.
 * Of course, by the time you were hired, GQ Bob had been running the joint and it wouldn't surprise me one bit that he'd didn't even know what the name of the company was.
 * Atlant 22:40, 10 September 2007 (UTC)

 * I guess I wouldn't rely on the company name in marketing pubs or tech manuals from 1962. The acquisition by Compaq occurred in 1998, and a lot of restructuring happened between 1962 and then. As I said, ALL the legal documents that were included in our bids and proposals gave the legal name as Digital Equipment Company. --NameThatWorks 17:36, 27 September 2007 (UTC)

 * The above claim is spurious. The stock certificates, the SEC documents, annual reports, etc. all refer to the actual name, Digital Equipment Corporation. patsw (talk) 19:33, 15 January 2008 (UTC)

I can't be sure at this late date, but I think when I started work for DEC in the UK (1977) I was working for Digital Equipment Company, a subsidiary (or something) of Digital Equipment Corporation. --dave, 2009-07-01 22:20-0400 —Preceding unsigned comment added by 151.203.11.215 (talk)

Details...
I noticed a few details that maybe should be corrected/cleared up.

First of all, I don't believe the DECtape was created for the PDP-10. I think the DECtape actually predates the PDP-10. If I remember correctly, the DECtape was pretty much based straight off from the LINKtape, with a few changes. It definitely exists for PDP-8, PDP-10 and PDP-11 systems (since I've observed those), but I think it was used on 18-bit systems as well.

Second, the C language didn't originate on the PDP-7. It might just be that I'm reading too much into that section, but to me it appears as if that is claimed. Unix ran on the PDP-7, yes, but that was written in assembler. The same is true for the early versions of Unix on the PDP-11. It was only rewritten in C after a few iterations on the PDP-11 had already been done.

Under the list of what happened to various DEC produects, I'm missing the disk manufacturing. Sure, DEC retained StorageWorks, but the actual disks was sold. If I remember, that went to Seagate.

Oh, and could someone find a proper logo? Blue, that is, not the (pretty recent) burgundy or whatever the color was called... :-)

/bqt@softjar.se 213.115.50.13 (talk) 17:19, 16 January 2008 (UTC)

 * Our DECtape article claims that it dates back to the PDP-6. It was certainly sold on at least some members of the 18-bit family, probably as old as the PDP-9.
 * The bulk of the storage group (i.e., "Colorado Springs") was sold to Quantum (which itself was subsequently sold).
 * Atlant (talk) 02:09, 17 January 2008 (UTC)

Other innovations and achievements
Having just finished reading Ed Schein's book on DEC (DEC Is Dead, Long Live DEC - Schein 2003) I wonder whether this article might be enhanced by some additional emphasis on DEC's role as one of the first learning organisations. As well as the technology legacy, Schein observes that DEC was one of the first companies to explore democratic management, and made significant innovations in community relations and corporate social responsibility, affirmative action, people development and human resource practices, leadership and management, team building (including virtual teams supported by the internal network Easynet), sales methods and practices, and even marketing innovations such as DECworld. Redwaterjug (talk) 21:06, 8 February 2008 (UTC)

 * Maybe include an example of DEC culture.
 * From around 1984 onwards DEC employees used Notes-11 (later called VaxNotes) to conduct what oday is called Web 2.0 Social Networking. From 1985 until I left in 1993 I used Vaxnotes in much the same way I use LinkedIn Professional Groups today 25+ years later.  VaxNotes didn't have the invitation to join my network feature however.
 * See http://mikeg.typepad.com/perceptions/2009/01/why-history-is-relevant-to-the-future-of-collaboration.html The section titled What the story about VxxNotes tells us...
 * Timelard (talk) 19:40, 10 February 2009 (UTC)

 * Weak arguments for the following reasons...
 * 1960, and 'the sixties', are at least about 200 years after corporate 'learning' began in North America.
 * The list of positive highlights you present here are extremely subjective.
 * The list of positive highlights you present here led to the company's failure while the market was exploding.
 * The article already skirts the 'neutrality' guidelines for Wikipedia.
 * markB (talk) 05:16, 2 January 2013 (UTC)

 * I request more objectivity and less redirection from this encyclopedia to a commercial product's marketing page.
 * 'Type Pad' reference links are commercial promotion. Wikipedia is not the place for such.
 * Implying that this company invented social networking and web 2.0 is ridiculous.
 * markB (talk) 05:34, 2 January 2013 (UTC)

 * Ridiculous sounds quite emotional to me. Can you explain why you think the idea is ridiculous? I was a regular VAXnotes user from '89 to '95. And indeed, it was used very much of a social network. Just without the images and the information pushing. Fungee (talk) 13:36, 12 March 2014 (UTC) Fungee

Structure of article
This article severely needs to be restructured in chronological sequence. Grouping products by the architecture type does not really accurately reflect how this company developed, unlike, say, Intel. Also, one tidbit that should be added -- DEC produced some very hard drives for a long time. During the late 1980s and early 1990s, they were among the best (if not the best) in the business. As part of the dismantling of the company in the early 1990s, that group was sold to Quantum. The Quantum Atlas line was the result. This facility passed through Maxtor, and then to Seagate. The DEC Shrewsbury facility still operational. 66.92.132.155 (talk) 05:27, 24 February 2008 (UTC)

ftp.digital.com
It seems that HP has retired the server that runs ftp.digital.com. The announcement can be found here: http://h18002.www1.hp.com/alphaserver/options/asgs1280/asgs1280_options.html

The ftp service is now inaccessible. The ftp.digital.com link(s) at the bottom of this page should be replaced with another link that provides the same information if possible, or removed. Rilak (talk) 08:08, 28 February 2008 (UTC)

Closing DEC's business
The sentence "However, Palmer was unable to stem the tide of red ink." has been bothering me for some time, and I was wondering if anybody had any comments about this: I know we need to keep away from anything that's perhaps largely based on opinion and possibly rather subjective, which is why I'm not inclined to change anything myself since I'm not certain the exact facts of the matter, but wasn't Palmer actually responsible for much (most?) of the red ink in question? I do recall that the number of vice presidents doubled (or more) under Palmer and the number of managers appeared to rise exponentially during the swathes of layoffs; and Palmer's own bio here on Wikipedia does indicate his fondness for restructuring, something that was a constant blight on the company to the point where many people were simply unable to do their jobs. And apart from anything, "was unable to" seems a curiously disempowering statement for the man who was in total control of the organisation.

I'm aware that we must be neutral and not allow personal feelings to negatively influence what's documented, but I think that the article goes much too far the other way, it's far too favourable and actually exonerates Palmer of his responsibilities. While I think that Wikipedia's account is far less inaccurate than other versions of DEC's demise, some of which are just blatantly untrue (though I figure it probably isn't helpful to comment further!) I think that this section could probably do with some attention. — Chris (blather • contribs) 15:29, 23 June 2008 (UTC)

 * I agree and disagree with you.
 * The entire sentence 'However, ... ink' is subjective. It could read '.. Yet, losses continued'.
 * You allude to having detailed historical knowledge of this company by means of mentioning inaccuracies of numerous and presumably disassociated commentaries regarding the company's demise. You remind me of just how difficult it is to remain neutral and objective.  I wonder if you struggle with the same concept.  Wikipedia is not the place to champion for redress or vindication.  You mention Palmer in the light of one who likely escaped blame for something, and this blatantly indicates you are probably championing for another individual indirectly.  Was he 'fond of restructuring' or did he often restructure.  There is a difference.
 * markB (talk) 06:16, 2 January 2013 (UTC)

 * I'm just someone who worked there. — Christine (blather • contribs) 13:51, 18 February 2013 (UTC)

"DEC alphabet"
I think it's incorrect to credit DEC with the idea of not using letters which are homoglyphs or near-homoglyphs. I expect there are several examples of prior art - one that springs to my mind are United Kingdom military aircraft serials, which have omitted the letters C, I, O, Q, U and Y since 1940. Letdorf (talk) 09:56, 9 October 2008 (UTC).

Citation for Assertion about the X Window System
Besides tons of messages in mail archives, I gave an invited talk at Usenix some years ago to cover (some of X's) history. I leave it to someone who knows wiki markup better than me to add it to the main article JimGettys (talk) 21:31, 19 November 2008 (UTC)

http://www.usenix.org/events/usenix2000/invitedtalks/gettys_html/

Famous people who worked at DEC
Added Radia Perlman because of her many achievements. —Preceding unsigned comment added by 161.130.5.129 (talk) 20:01, 15 January 2009 (UTC)

You did not like my coffee-mug?
On 2 apr 2009 10:55 User:Badger Drink removed my original/historical Digital coffee-mug? What do the others think? Geert Van Pamel (talk) 00:23, 28 April 2009 (UTC)
 * Ken Olsen's primary concern about customers and employees "Our Employees are our greatest Asset" was distributed on a coffee mug, to encourage all employees.

 * I do like your coffee mug picture, as evidence of Ken Olsen's attitude towards DEC employees. I suggest moving it to the biographical article about him, which is sadly in need of good pictures, including a picture of the man himself. Reify-tech (talk) 20:15, 21 March 2011 (UTC)

64 bits binaries are bigger and adressing 64 bits was unnecessary
I added this sentence concerning the DEC Alpha but it has been suppressed because of lack of citations:

 * A 64-bit CPU was also too early in the sense that 64-binaries were about 3 to 4 times bigger than 32-bits binaries and memories and hard drives were costly at that time. The ability to address 64 bits was also not seen as a priority even for scientific applications.

But there are no citation for the other parts concerning DEC Alpha and I remember very well discussing with DEC people and testing their first 64 bits binaries. It was obvious for researchers involved in computer science at that time. We have worked on Univac machine whichs were 36 bits, they did not add so much in comparison with IBM 32 bits for scientific computations. Also when the VAX came, its main advantage was virtual memory and its ability to swap its memory on hard disk. And thus adressing full 32 bits was just possible with a VAX, and it made its success. But adressing 64 bits was not a real need. I remember Digital saying: Yes, it is not the current need for scientists now, but it will come and we are offering you 64 bits machines at the price of 32 bits machines. And it wasn't true, because we needed to buy many more memory which was very costly. And thus if somebody find citations, the above sentence could be reinserted.--Nbrouard (talk) 16:50, 13 July 2010 (UTC)

 * "3 to 4" is questionable, unless you can find some authoritative source which gives that, e.g., based on instruction set efficiencies of RISC vs CISC, with the numbers coming from the source. Otherwise, it's just hazy recollections Tedickey (talk) 19:23, 13 July 2010 (UTC)

 * I do not think that the content in question is accurate or relevant. Firstly, why should a 64-bit binary be approximately three to four times larger than a 32-bit binary? Apart from the larger pointers and possible padding, the binaries should be similar in size if the 32-bit ISA and 64-bit ISA were similar. Am I missing something? I think that the point itself is inaccurate. If the previous version of the binary was compiled for VAX, and the subsequent version was ported to Alpha or translated, then the binary would be significantly larger. This is however not a consequence of the Alpha being 64-bit, but rather VAX being CISC and Alpha being RISC. Rilak (talk) 11:48, 19 July 2010 (UTC)
 * Yes, both effects were interacting. And the RISC versus CISC was probably the main effect over larger pointers. Having an IBM/RS6000 as my first RISC machine, I remember much smaller binaries than on our Alpha 64 bit. But again, it could come from other reasons that I never investigated. My main point was that the cost of memory was very high when the Alpha came and it was a very sensitive issue: 1 Mb of memory was 5,000 $ in 1977 and 6$ in 1994 .--Nbrouard (talk) 09:58, 24 July 2010 (UTC)

 * Secondly, I do not think that the point regarding 64-bit addressing being not required when the Alpha was introduced is relevant. Alpha was designed to last 25 years per the paper by Richard L. Sites published in Communications of the ACM. If I remember correctly, the inclusion of 64-bit addressing capability was a direct consequence of predictions showing that by the mid- or late 1990s, the ability to address more than 32 bits of memory was nessecary in both high-end commercial and scientific applications. Rilak (talk) 11:48, 19 July 2010 (UTC)
 * Everyone agreed on the utility of addressing 64 bits in the future. Altavista was probably the first example of such use. But for researchers, moving from mainframes to workstations, it was not so urgent. Even today, I still prefer 32 bit Linux to avoid many unsolved problems. Mac OS/X just implemented its first 64 bit OS in late 2009.--Nbrouard (talk) 09:58, 24 July 2010 (UTC)

 * Ironically, if I remember correctly, the first version of the Alpha ISA did not support a full 64-bit address space, several bits were reserved, and these could be used to implement a full 64-bit address space in the future. In addition to this, none of the Alpha implementations have ever supported 64-bit addressing in virtual or physical form.
 * As Tedickey has said, the content in question is questionable and requires citations to authorative sources if it is to be included in the article. Additionally, the lack of citations for the rest of the section does not necessarily mean that it is inaccurate, and it does not mean that questionable claims should be inserted. If there uncited claims that should be scrutinized, then they should be pointed out here. Rilak (talk) 11:48, 19 July 2010 (UTC)

 * These points have been debated with DEC and, from my point of view, never solved completely in 1992; thank you for giving me the opportunity to discuss again and clarify these points 18 years after.--Nbrouard (talk) 09:58, 24 July 2010 (UTC)

Major edits made during March 2010
In March 2010, a series of major edits were made that introduced major changes into the article. One of the changes made greatly concerns me. It is in regards to DEC's PC product lines during the 1990s. If one looks at the revision from 25 Feb. 2010, one will find that DEC's PC product lines of the 1990s are mentioned. This is very important because DEC's Alpha business only constituted less than a third of the company's revenue, IIRC. The other major hardware product line were PCs. The omission of these product changes how the article reads. Before, it was: "DEC failed in early its PC attempts, but it eventually got out some PC product lines during the 1990s." Now it reads like this: "Stupid DEC failed in its early PC attempts, it never tried to get back into the PC market, and left only with silly overpriced closed VAX systems, DEC failed. What a bunch of dinosuars! LOL!" Not NPOV is it?

I would fix it myself, if there was a section that I could put it in. But the article structure was altered significantly, and it is not much better from the previous structure. The issue remains the same. Trying to tell DEC's history by organizing it into sections around product lines mixed with out-of-place sections about specific happenings doesn't work. Why? Because DEC's product lines overlap each other. It also encourages work on the products, not the history. And it is a problem as people for some reason don't seem to realize that Wikipedia has articles on the products, so they add detailed information about products into an article that was not meant to be about the products.

The article needs to be rewritten entirely. The present version is poorly structured and it misses the point. For example, if one were to look in Electronics, the articles from the late 1980s say that DEC got successful from one ISA, one OS, one product line from workstations to superminicomputers, networking, and VAXclusters. And then it began to decline because of client/server computing, open platforms, and RISC microprocessors. The current article doesn't say this explicitly, it barely even mentions these points, and it implies that what caused DEC's demise were "business microcomputers". In regards to structure, the history should be organized by decade, not by product. This will allow the article to read more smoothly and allow it to show relations between events and products that are presently disjointed.

Have the problems that I described been noticed by other editors? Are there any comments about my proposed solutions or my comments in general? Rilak (talk) 04:13, 20 August 2010 (UTC)

Proposed major restructuring of article
I think Rilak's comments above have considerable merit. A better overview of the evolution of DEC should be presented in this article, beyond a simple chronicle of different product lines. For example, the long-standing influence and then departure of Gordon Bell at the highest levels of DEC management was a significant factor in the rise and fall of DEC. Bell reputedly was one of the few people within DEC who could tell Ken Olsen to his face that he was completely wrong, and still be listened to. His involvement in multiple product lines was more than incidental, in that he guided much of the "big picture" strategic technical vision of the company. As Rilak points out, DEC continued to make products for the PC market into the 1990s, and these products were an influential presence in the market, even if they failed to achieve market dominance.

IIRC, the book by Edgar Schein et. al. "DEC is Dead, Long Live DEC" was chronologically organized. I don't have a copy at hand right now, but I remember that the book's coverage correlated well with my experience as a long-time DEC user and acquaintance of many DEC employees. The book is already listed as a reference for many DEC-related articles, and is a must-read for anybody interested in better understanding the rise and fall of DEC, as well as its continuing legacies.

Rather than the daunting (and possibly controversial) project of reorganizing the entire article at one fell swoop, perhaps it would be better to start a new section organized chronologically, as a parallel overview of DEC's history. It could absorb some of the existing non-product-line sections of the article, and also host new content such as the history of DEC's PC efforts in the 1990s. If and when it becomes apparent that the product-line oriented approach has been superseded, the remaining content could be subsumed into the chronological narrative, or broken out as separate subsidiary articles.

In other words, start building something better, before making the major change of deconstructing the current article organization. Reify-tech (talk) 21:20, 21 March 2011 (UTC)

 * Please remember that any new material should reference reliable sources. Schein doesn't go into a lot of technical detail - better technical history material can be found at Gordon Bell's website particularly the DEC timeline . Regards, Letdorf (talk) 22:18, 21 March 2011 (UTC).

 * Agreed. It's easy for articles to become list of individual things, and completely miss the larger picture.  What brought me here was the use of Template:Hard_disk_drive_manufacturers when hard disks are never mentioned in the article!  Did DEC actually manufacturer these at any point?  I know they were big with tape, and sold DLT to Quantum.  --Juventas (talk) 20:39, 19 June 2011 (UTC)

 * DEC did manufacture its own disk drives, as well as buying them from other manufacturers (e.g. Memorex for RP series, CDC for RM series).  IIRC,  they had a disk and tape division in Colorado Springs (Colorado Memory Systems Division??), which developed hard disk systems (removable and fixed), and also developed the DLT (Digital Linear Tape) systems.   I think the disk division started with the RK05 (14-inch single platter, removable cartridge, 2.5MB).  They managed to keep up with the rest of the industry until the late 1980s, when DEC's financial problems started to impede their ability to invest in advancing the technology.  They also had reliability problems with the RA90 hard disk.  When DEC started to founder, they sold the entire disk/tape division to Quantum Corporation to raise quick cash.  All this is written from memory, as I don't have my old DEC literature at hand (it's in storage).  Anyway, the whole disk/tape division story is a saga in itself, significant but a sideshow in the whole story of DEC.
 * The DEC article as it stands now isn't that bad, but it suffers from large gaps in its coverage (e.g. the disk/tape division) and needs better integrated "big picture" coverage of the mid 1980s and later. Perhaps the article should have a — I hesitate to say this — "matrix" organization?  I mean by this that a historical/chronological approach should be built up, spanning the many DEC product lines and research efforts.  This would complement the existing product-oriented coverage, without requiring it to be completely torn apart and rebuilt on the fly.
 * Unfortunately, I don't know of any secondary-source definitive history of DEC that really fits the bill. The books by  Schein, Bell/Mudge/McNamara, and Ceruzzi are the best sources I know of so far, and they all have their limitations.  Any other suggestions?
 * I'm not up to taking the lead on this whole thing, though I could help out in areas I have some experience with. I'm just reluctant to start tearing the current article apart, without the certainty that something better will immediately be built in its place.  That's why I'm suggesting a parallel build with a chronological framework, while leaving most of the existing structure in place. Reify-tech (talk) 00:52, 20 June 2011 (UTC)

unsourced/exaggerated synopses of notable people
The comments for Cutler and Getty far exceed their actual accomplishments. TEDickey (talk) 01:25, 24 May 2012 (UTC)

 * Apologies for the sloppy edits; I was in a hurry at that time. Of course there were many other people working on those projects. I've modified the summary descriptions, and hope they are more accurate and acceptable.  You're certainly welcome and invited to improve them further.  --Reify-tech (talk) 01:52, 24 May 2012 (UTC)

somewhat exaggerated but a significant player.
- Two people led the RSX-11 team of which Cutler was 1

- Three people led the VMS development team of which Cutler was 1

This is fairly well documented in the various books published by the Corporations own "DEC Press" / "Digital Press".

Furthermore - RSX was not such a complicated system to be developing an OS for ex. a total of 64KB real memory! so a bit exaggerated.

Whilst Cutler was 1/3 leading the VMS 1.0 Development in 1974 there were 14 releases over some 30 years. He did however contribute to some of what would be significant formative & characteristic design of early VMS but did not stay around to contribute to even bigger stuff like Clusters and SMP back in the 1980s when nobody else even knew what that meant.

His BS was in Physics at a time when Universities did not teach Computer Science. So he learned everything on the job (unheard of these days).

He then left NH for CA to set up WRL to do new work on RISC with his MICA project. Another technological innovation which the business (back then) had no use for. This was the final straw for him.

The next 3 years were spent in the wilderness before he eventually got the call from Bill Gates.

Most memorable Cutler Quote, "Getting past HR is the most difficult part of the Job".

Mld01 (talk) 21:14, 31 January 2018 (UTC)

General vagueness in paragraph
"In the period 1994–99 Linus Torvalds developed versions of Linux on early AlphaServer systems made available to him by the engineering department. Compaq software engineers developed special Linux kernel modules"

You cannot mention Compaq to the effect it is substitutable for Digital Equipment

Alphaserver hardware first commercial shipping was during 1993. There were already a comprehensive range of platforms ready to go. Workstations, Servers, Datacentre Systems. so 'early Alphaserver' is vague & misleading.

Linus Torvalds is not in any way part of the Digital Equipment Story.

By direct comparison 20% of the DECs substantial OS budget went into staffing & running out of the DEC WRL office a Digital Internal Engineering Group effort to Port under Licence from Microsoft NT v1.0.

Mld01 (talk) 21:52, 31 January 2018 (UTC)

Linux not DEC-accomplishment
The couple of unsourced comments about Linux don't belong in the section on DEC's accomplishments. Further, the two sentences don't belong together, since they apparently equate events that took place several years apart. TEDickey (talk) 01:15, 27 July 2014 (UTC)

 * Yeah, DEC has a lot of accomplishments to its credit, but Linux is definitely not one of them. Reify-tech (talk) 02:48, 27 July 2014 (UTC)

 * Agree and removed both. Tom94022 (talk) 16:12, 27 July 2014 (UTC)

 * Compaq was actively developing core modules for Linux!
 * I do not agree... I would propose to again add the paragraph, and to refer to http://www.informatica.co.cr/linux/research/1999/0302-a.htm where it clearly is indicated that Compaq was actively participating during the period 1994-1999 into the Linux development... both with hardware and software Geertivp (talk) 20:36, 31 July 2014 (UTC)

 * I did not know that DEC made any contributions to Linux development, but you have found what looks like good documentation of some efforts after Compaq acquired it. It's too bad DEC didn't start earlier.  Reify-tech (talk) 20:52, 31 July 2014 (UTC)

 * And here you have the reference for Red Hat 7.2 http://www.informatica.co.cr/linux/research/2002/0108.htm (January 8, 2002). Also the Gentoo distribution was ported to AlphaServer... So, please add again the deleted paragraph about Linux on AlphaServer... Geertivp (talk) 21:22, 31 July 2014 (UTC)

 * I added the paragraph again, with references Geertivp (talk) 22:11, 31 July 2014 (UTC)

 * It would have been nice if your change comment had reflected that you modified the content (reverting is different). By the way, your source is a press release, which isn't really that good in itself, since largely those are promotional and not close to fact. TEDickey (talk) 22:44, 31 July 2014 (UTC)

I still fail to see how either could be fairly categorized as a DEC accomplishment. It was first developed for x86 and then ported to many systems; what makes this port a DEC accomplishment particularly when it is not clear that DEC did the porting? Likewise, its hard to see how LINUX on an alphaserver after DEC disappeared is a DEC accomplishment, Compaq, maybe, but even there is a port an accomplishment worthy of Wikipedia inclusion. If everything done on a DEC system is a DEC accomplishment then the list needs to be a lot longer, so I still support removing the two cites. Right now there does not appear to be a consensus - let's see what others say. Tom94022 (talk) 23:50, 31 July 2014 (UTC)

UNIX / Linux History suggests the only thing DEC did was lend Torvald's a computer - is that worthy of inclusion in Wikipeida as a DEC accomplishment? Tom94022 (talk) 00:01, 1 August 2014 (UTC)

 * The given change and its source are promotional rather than encyclopedic, and lacking genuine third-party sources, there's not much to discuss. TEDickey (talk) 00:02, 1 August 2014 (UTC)

 * I would propose to move the paragraph to the 32-bit MIPS and 64-bit Alpha systems section... still it is a worth-full fact, even if you would not consider it a huge accomplishment...
 * Evidence: Compaq released multiple kernel modules under General Public License (GPL) and assigned full-time engineers to help the Linux community to port and optimize Linux on the Alpha platform.
 * Geertivp (talk) 06:25, 1 August 2014 (UTC)

 * you are not responding to other editor's comments. here for instance is a copy of the original press release.  As noted, your suggested sources are sketchy, promotional, and based on a timeframe after the range when DEC was an independent actor separate from its acquisition by Compaq. TEDickey (talk) 07:51, 1 August 2014 (UTC)

 * See Jon_Hall_(programmer) for further references; it was clearly as of 1994 that the port of Linux to AlphaServer was started as stimulated by Jon Hall, 4 years before Digital Equipment was taken over by Compaq... Geertivp (talk) 19:19, 5 August 2014 (UTC)

 * There aren't any dates cited in that topic which bear on this discussion. Perhaps you found something in a reference which you meant to share with other editors. TEDickey (talk) 00:43, 6 August 2014 (UTC)

 * In May of 1994 Linus Torvalds was financed by DEC's Unix Marketing Group to attend DECUS in New Orleans at the urging of the Chair of the Unix Special Interest Group. Mr. Kurt Reisler. There Linus gave two talks about Linux and showed an Intel 32-bit distribution based on his V1.0 kernel to Jon_Hall_(programmer), who then went back to Digital and arranged for Linus to receive a DEC Alpha machine.   Jon_Hall_(programmer) saw a great use for Linux on a 64-bit, RISC architecture to be used for computer science research in large address spaces. Jon_Hall_(programmer) also found a small group of programmers in the DEC Semiconductor group headed up by Andy Riebs, Jim Paradis, Jay Estabrook and David Rusling (among others) who did significant amount of engineering work to help with the porting of the kernel.  David Rusling wrote a Free Software bootloader for the Alpha called "Milo", because the boot-loader that came with the Alpha was not Free Software.   Jon_Hall_(programmer) also arranged for the Digital Semiconductor group to have access to another DEC Alpha processor for their work. DEC Alpha machines were very expensive in 1994, not as inexpensive as many computers are today, and many DEC engineers did not have access to an Alpha for their own use on operating systems like VMS and DEC Unix.  In addition, DEC helped the port by making technical documentation available to members of the Linux community.  In November of 1995 Digital sponsored the production of 4000 CDs of Red Hat 2.1, the first version of Red Hat to run on the Alpha, and gave these away at trade shows and conferences around the world.  Many engineers in the Digital Unix Group of DEC were already using Linux on their laptops to do work, and contributed to the port.  This port was also the first that Linus Torvalds actively participated in.  Before this the ports to other processors were forks copied off the Linux kernel tree that other people were porting.  For this port, Linus created an "N" way (as opposed to two-way) source code tree so other ports in the future would not be as difficult.  It was also the first time that Linux was positioned as either a 32-bit or 64-bit kernel. Later, after distributions of "Alpha/Linux" started to stabilize, DEC also formed a group called "Computer Special Systems" that sold Beowulf Clusters made of DEC Alpha Systems.  This was a fairly successful business.  It was January of 1998 when Compaq announced it was buying Digital Equipment Corporation, and fully a year after that before Digital was assimilated.  During that time we found that some Compaq engineers and groups were also supporting Linux. Maddoghall (talk) 23:05, 20 November 2015 (UTC)

DEC
Dec is a corporation that died and merged with other corporations. — Preceding unsigned comment added by 75.114.77.38 (talk) 17:26, 19 April 2017 (UTC)

 * Yup. What's your point? Garchy (talk) 17:29, 19 April 2017 (UTC)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Talk:Digital Equipment Corporation


text:
Diamagnetism

Diamagnetism is the property of materials that are repelled by a magnetic field; an applied magnetic field creates an induced magnetic field in them in the opposite direction, causing a repulsive force. In contrast, paramagnetic and ferromagnetic materials are attracted by a magnetic field. Diamagnetism is a quantum mechanical effect that occurs in all materials; when it is the only contribution to the magnetism, the material is called diamagnetic. In paramagnetic and ferromagnetic substances, the weak diamagnetic force is overcome by the attractive force of magnetic dipoles in the material. The magnetic permeability of diamagnetic materials is less than the permeability of vacuum, μ0. In most materials, diamagnetism is a weak effect which can be detected only by sensitive laboratory instruments, but a superconductor acts as a strong diamagnet because it entirely expels any magnetic field from its interior (the Meissner effect).

Diamagnetism was first discovered when Anton Brugmans observed in 1778 that bismuth was repelled by magnetic fields. In 1845, Michael Faraday demonstrated that it was a property of matter and concluded that every material responded (in either a diamagnetic or paramagnetic way) to an applied magnetic field. On a suggestion by William Whewell, Faraday first referred to the phenomenon as diamagnetic (the prefix dia- meaning through or across), then later changed it to diamagnetism.

A simple rule of thumb is used in chemistry to determine whether a particle (atom, ion, or molecule) is paramagnetic or diamagnetic: If all electrons in the particle are paired, then the substance made of this particle is diamagnetic; If it has unpaired electrons, then the substance is paramagnetic.

Materials

Diamagnetism is a property of all materials, and always makes a weak contribution to the material's response to a magnetic field. However, other forms of magnetism (such as ferromagnetism or paramagnetism) are so much stronger such that, when different forms of magnetism are present in a material, the diamagnetic contribution is usually negligible. Substances where the diamagnetic behaviour is the strongest effect are termed diamagnetic materials, or diamagnets. Diamagnetic materials are those that some people generally think of as non-magnetic, and include water, wood, most organic compounds such as petroleum and some plastics, and many metals including copper, particularly the heavy ones with many core electrons, such as mercury, gold and bismuth. The magnetic susceptibility values of various molecular fragments are called Pascal's constants (named after Paul Pascal (physicist)).

Diamagnetic materials, like water, or water-based materials, have a relative magnetic permeability that is less than or equal to 1, and therefore a magnetic susceptibility less than or equal to 0, since susceptibility is defined as. This means that diamagnetic materials are repelled by magnetic fields. However, since diamagnetism is such a weak property, its effects are not observable in everyday life. For example, the magnetic susceptibility of diamagnets such as water is. The most strongly diamagnetic material is bismuth,, although pyrolytic carbon may have a susceptibility of  in one plane. Nevertheless, these values are orders of magnitude smaller than the magnetism exhibited by paramagnets and ferromagnets. Because χv is derived from the ratio of the internal magnetic field to the applied field, it is a dimensionless value.

In rare cases, the diamagnetic contribution can be stronger than paramagnetic contribution. This is the case for gold, which has a magnetic susceptibility less than 0 (and is thus by definition a diamagnetic material), but when measured carefully with X-ray magnetic circular dichroism, has an extremely weak paramagnetic contribution that is overcome by a stronger diamagnetic contribution.

Superconductors
Superconductors may be considered perfect diamagnets, because they expel all magnetic fields (except in a thin surface layer) due to the Meissner effect.

Curving water surfaces
If a powerful magnet (such as a supermagnet) is covered with a layer of water (that is thin compared to the diameter of the magnet) then the field of the magnet significantly repels the water. This causes a slight dimple in the water's surface that may be seen by a reflection in its surface.

Levitation

Diamagnets may be levitated in stable equilibrium in a magnetic field, with no power consumption. Earnshaw's theorem seems to preclude the possibility of static magnetic levitation. However, Earnshaw's theorem applies only to objects with positive susceptibilities, such as ferromagnets (which have a permanent positive moment) and paramagnets (which induce a positive moment). These are attracted to field maxima, which do not exist in free space. Diamagnets (which induce a negative moment) are attracted to field minima, and there can be a field minimum in free space.

A thin slice of pyrolytic graphite, which is an unusually strongly diamagnetic material, can be stably floated in a magnetic field, such as that from rare earth permanent magnets. This can be done with all components at room temperature, making a visually effective and relatively convenient demonstration of diamagnetism.

The Radboud University Nijmegen, the Netherlands, has conducted experiments where water and other substances were successfully levitated. Most spectacularly, a live frog (see figure) was levitated.

In September 2009, NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California announced it had successfully levitated mice using a superconducting magnet, an important step forward since mice are closer biologically to humans than frogs. JPL said it hopes to perform experiments regarding the effects of microgravity on bone and muscle mass.

Recent experiments studying the growth of protein crystals have led to a technique using powerful magnets to allow growth in ways that counteract Earth's gravity.

A simple homemade device for demonstration can be constructed out of bismuth plates and a few permanent magnets that levitate a permanent magnet.

Theory
The electrons in a material generally settle in orbitals, with effectively zero resistance and act like current loops. Thus it might be imagined that diamagnetism effects in general would be common, since any applied magnetic field would generate currents in these loops that would oppose the change, in a similar way to superconductors, which are essentially perfect diamagnets. However, since the electrons are rigidly held in orbitals by the charge of the protons and are further constrained by the Pauli exclusion principle, many materials exhibit diamagnetism, but typically respond very little to the applied field.

The Bohr–Van Leeuwen theorem proves that there cannot be any diamagnetism or paramagnetism in a purely classical system. However, the classical theory of Langevin for diamagnetism gives the same prediction as the quantum theory. The classical theory is given below.

Langevin diamagnetism
Paul Langevin's theory of diamagnetism (1905) applies to materials containing atoms with closed shells (see dielectrics). A field with intensity $B$, applied to an electron with charge $e$ and mass $m$, gives rise to Larmor precession with frequency $ω = eB / 2 m$. The number of revolutions per unit time is $ω / 2\pi$, so the current for an atom with $Z$ electrons is (in SI units)

 * $$ I = -\frac{Ze^2B}{4 \pi m}.$$

The magnetic moment of a current loop is equal to the current times the area of the loop. Suppose the field is aligned with the $z$ axis. The average loop area can be given as $$\scriptstyle \pi\left\langle\rho^2\right\rangle$$, where $$\scriptstyle \left\langle\rho^2\right\rangle$$ is the mean square distance of the electrons perpendicular to the $z$ axis. The magnetic moment is therefore

 * $$ \mu = -\frac{Ze^2B}{4 m}\langle\rho^2\rangle.$$

If the distribution of charge is spherically symmetric, we can suppose that the distribution of $x,y,z$ coordinates are independent and identically distributed. Then $$\scriptstyle \left\langle x^2 \right\rangle \;=\; \left\langle y^2 \right\rangle \;=\; \left\langle z^2 \right\rangle \;=\; \frac{1}{3}\left\langle r^2 \right\rangle$$, where $$\scriptstyle \left\langle r^2 \right\rangle$$ is the mean square distance of the electrons from the nucleus. Therefore, $$\scriptstyle \left\langle \rho^2 \right\rangle \;=\; \left\langle x^2\right\rangle \;+\; \left\langle y^2 \right\rangle \;=\; \frac{2}{3}\left\langle r^2 \right\rangle$$. If $$n$$ is the number of atoms per unit volume, the volume diamagnetic susceptibility in SI units is

 * $$\chi = \frac{\mu_0 n \mu}{B} = -\frac{\mu_0e^2 Zn }{6 m}\langle r^2\rangle.$$

In atoms, Langevin susceptibility is of the same order of magnitude as Van Vleck paramagnetic susceptibility.

In metals
The Langevin theory is not the full picture for metals because there are also non-localized electrons. The theory that describes diamagnetism in a free electron gas is called Landau diamagnetism, named after Lev Landau, and instead considers the weak counteracting field that forms when the electrons' trajectories are curved due to the Lorentz force. Landau diamagnetism, however, should be contrasted with Pauli paramagnetism, an effect associated with the polarization of delocalized electrons' spins. For the bulk case of a 3D system and low magnetic fields, the (volume) diamagnetic susceptibility can be calculated using Landau quantization, which in SI units is

 * $$\chi = -\mu_0\frac{e^2}{12\pi^2 m\hbar}\sqrt{2mE_{\rm F}},$$

where $$E_{\rm F}$$ is the Fermi energy. This is equivalent to $$-\mu_0\mu_{\rm B}^2 g(E_{\rm F})/3$$, exactly $-1/3$ times Pauli paramagnetic susceptibility, where $$\mu_{\rm B}=e\hbar/2m$$ is the Bohr magneton and $$g(E)$$ is the density of states (number of states per energy per volume). This formula takes into account the spin degeneracy of the carriers (spin-1/2 electrons).

In doped semiconductors the ratio between Landau and Pauli susceptibilities may change due to the effective mass of the charge carriers differing from the electron mass in vacuum, increasing the diamagnetic contribution. The formula presented here only applies for the bulk; in confined systems like quantum dots, the description is altered due to quantum confinement. Additionally, for strong magnetic fields, the susceptibility of delocalized electrons oscillates as a function of the field strength, a phenomenon known as the De Haas–Van Alphen effect, also first described theoretically by Landau.

title: Diamagnetism


text:
Duke of Marlborough (title)

Duke of Marlborough ( pronounced ) is a title in the Peerage of England. It was created by Queen Anne in 1702 for John Churchill, 1st Earl of Marlborough (1650–1722), the noted military leader. In historical texts, unqualified use of the title typically refers to the 1st Duke. The name of the dukedom refers to Marlborough in Wiltshire.

The earldom of Marlborough was held by the family of Ley from its creation in 1626 until its extinction with the death of the 4th earl in 1679. The title was recreated 10 years later for John Churchill (in 1689).

History of the dukedom
Churchill had been made Lord Churchill of Eyemouth (1682) in the Peerage of Scotland, and Baron Churchill of Sandridge (1685) and Earl of Marlborough (1689) in the Peerage of England. Shortly after her accession to the throne in 1702, Queen Anne made Churchill the first Duke of Marlborough and granted him the subsidiary title Marquess of Blandford.

In 1678, Churchill married Sarah Jennings (1660–1744), a courtier and influential favourite of the queen. They had seven children, of whom four daughters married into some of the most important families in Great Britain; one daughter and one son died in infancy. He was pre-deceased by his son, John Churchill, Marquess of Blandford, in 1703; so, to prevent the extinction of the titles, a special Act of Parliament was passed. When the 1st Duke of Marlborough died in 1722 his title as Lord Churchill of Eyemouth in the Peerage of Scotland became extinct and the Marlborough titles passed, according to the Act, to his eldest daughter Henrietta (1681–1733), the 2nd Duchess of Marlborough. She was married to Francis Godolphin, 2nd Earl of Godolphin and had a son who predeceased her.

When Henrietta died in 1733, the Marlborough titles passed to her nephew Charles Spencer (1706–1758), the third son of her late sister Anne (1683–1716), who had married the 3rd Earl of Sunderland in 1699. After his older brother's death in 1729, Charles Spencer had already inherited the Spencer family estates and the titles of Earl of Sunderland (1643) and Baron Spencer of Wormleighton (1603), all in the Peerage of England. Upon his maternal aunt Henrietta's death in 1733, Charles Spencer succeeded to the Marlborough family estates and titles and became the 3rd Duke. When he died in 1758, his titles passed to his eldest son George (1739–1817), who was succeeded by his eldest son George, the 5th Duke (1766–1840). In 1815, Francis Spencer (the younger son of the 4th Duke) was created Baron Churchill in the Peerage of the United Kingdom. In 1902, his grandson, the 3rd Baron Churchill, was created Viscount Churchill.

In 1817, the 5th Duke obtained permission to assume and bear the surname of Churchill in addition to his surname of Spencer, to perpetuate the name of his illustrious great-great-grandfather. At the same time he received royal licence to quarter the coat of arms of Churchill with his paternal arms of Spencer. The modern Dukes thus originally bore the surname "Spencer": the double-barrelled surname of "Spencer-Churchill" as used since 1817 remains in the family, although many members have preferred to style themselves simply as "Churchill".

The 7th Duke was the paternal grandfather of the British Prime Minister Sir Winston Churchill, born at Blenheim Palace on 30 November 1874.

The 11th Duke, John Spencer-Churchill died in 2014, having assumed the title in 1972. The 12th and present Duke is Charles James Spencer-Churchill.

Family seat
The family seat is Blenheim Palace in Woodstock, Oxfordshire.

After his leadership in the victory against the French in the Battle of Blenheim on 13 August 1704, the 1st Duke was honoured by Queen Anne granting him the royal manor of Woodstock, and building him a house at her expense to be called Blenheim. Construction started in 1705 and the house was completed in 1722, the year of the 1st Duke's death. Blenheim Palace has since remained in the Churchill and Spencer-Churchill family.

With the exception of the 10th Duke and his first wife, the dukes and duchesses of Marlborough are buried in Blenheim Palace's chapel. Most other members of the Spencer-Churchill family are interred in St. Martin's parish churchyard at Bladon, a short distance from the palace.

Succession to the title
The dukedom can theoretically pass through a female line. However, unlike the remainder to heirs general found in most other peerages that allow male-preference primogeniture, the grant does not allow for abeyance and follows a more restrictive Semi-Salic formula designed to keep succession wherever possible in the male line.

Succession to the title under the first and second contingencies has lapsed; holders of the title from the 3rd Duke trace their status from the third contingency.

It is now very unlikely that the dukedom will be passed to a woman or through a woman, since all the male-line descendants of the 1st Duke's second daughter Anne Spencer, Countess of Sunderland—including the lines of the Viscounts Churchill and Barons Churchill of Wychwood and of the Earl Spencer and of the entire Spencer-Churchill and Spencer family—would have to become extinct.

If that were to happen, the Churchill titles would pass to the Earl of Jersey, the heir-male of the 1st Duke's granddaughter Anne Villiers (born Egerton), Countess of Jersey, daughter of Elizabeth Churchill, Countess of Bridgewater, the fourth daughter of the first Duke.

Line of succession

 * Coronet of a British Duke.svg John Churchill, 1st Duke of Marlborough (1650–1722)
 * Coronet of a British Duke.svg Henrietta Churchill, 2nd Duchess of Marlborough (1681–1733)
 * Anne Churchill, Countess of Sunderland (1683–1716)
 * Coronet of a British Duke.svg Charles Spencer, 3rd Duke of Marlborough (1706–1758)
 * Coronet of a British Duke.svg George Spencer, 4th Duke of Marlborough (1739–1817)
 * Coronet of a British Duke.svg George Spencer-Churchill, 5th Duke of Marlborough (1766–1840)
 * Coronet of a British Duke.svg George Spencer-Churchill, 6th Duke of Marlborough (1793–1857)
 * Coronet of a British Duke.svg John Spencer-Churchill, 7th Duke of Marlborough (1822–1883)
 * Coronet of a British Duke.svg George Spencer-Churchill, 8th Duke of Marlborough (1844–1892)
 * Coronet of a British Duke.svg Charles Spencer-Churchill, 9th Duke of Marlborough (1871–1934)
 * Coronet of a British Duke.svg John Spencer-Churchill, 10th Duke of Marlborough (1897–1972)
 * Coronet of a British Duke.svg John Spencer-Churchill, 11th Duke of Marlborough (1926–2014)
 * Coronet of a British Duke.svg James Spencer-Churchill, 12th Duke of Marlborough (born 1955)
 * (1) George Spencer-Churchill, Marquess of Blandford (b. 1992)
 * (2) Lord Caspar Spencer-Churchill (b. 2008) $2$
 * (3) Lord Edward Spencer-Churchill (b. 1974) $2$
 * Lord Charles Spencer-Churchill (1940–2016)
 * (4) Rupert Spencer-Churchill (b. 1971) $2$
 * (5) Dominic Spencer-Churchill (b. 1979) $2$
 * (6) Ivor Spencer-Churchill (b. 2014)
 * (7) Alexander Spencer-Churchill (b. 1983) $2$
 * Lord Ivor Spencer-Churchill (1898–1956)
 * (8) Robert Spencer-Churchill (b. 1954)
 * (9) John Spencer-Churchill (b. 1984)
 * (10) Ivor Spencer-Churchill (b. 1986)
 * Lord Randolph Spencer-Churchill (1849–1895)
 * Sir Winston Churchill (1874–1965)
 * Randolph Spencer-Churchill (1911–1968)
 * Winston Spencer-Churchill (1940–2010)
 * (11) Randolph Spencer-Churchill (b. 1965)
 * (12) John Spencer-Churchill (b. 2007)
 * (13) John Spencer-Churchill (b. 1975)
 * (14) Edward Spencer-Churchill (b. 2008)
 * (15) Alexander Spencer-Churchill (b. 2014)
 * Coronet of a British Baron.svg Francis Spencer, 1st Baron Churchill (1779–1845)
 * Augustus Spencer (1807–1893)
 * Augustus Spencer (1851–1912)
 * Richard Spencer (1888–1956)
 * Coronet of a British Baron.svg Richard Spencer, 6th Baron Churchill (1926–2020)
 * (16) Coronet of a British Baron.svg Michael Spencer, 7th Baron Churchill (b. 1960)
 * (17) David Spencer (b. 1970)
 * (18) Thomas Ellison-Spencer (b. 2006)
 * William Spencer (1810–1900)
 * William Spencer (1838–1923)
 * John Spencer (1881–1952)
 * John Spencer (1917–1967)
 * (19) John Spencer (b. 1957)
 * (20) Charles Spencer (b. 1990)
 * Charles Spencer (1824–1895)
 * Charles Spencer (1848–1922)
 * Francis Spencer (1881–1972)
 * Francis Spencer (1917–1989)
 * (21) Philip Spencer (b. 1966)
 * Lord Charles Spencer (1740–1820)
 * John Spencer (1767–1831)
 * Frederick Spencer (1796–1831)
 * Charles Spencer (1827–1898)
 * Sir Charles Spencer (1869–1934)
 * John Spencer (1907–1977)
 * (22) Robert Spencer (b. 1944)
 * (23) Edmund Spencer (b. 1991)
 * Charles Spencer (1909–1963)
 * (24) Piers Spencer (b. 1963)
 * John Spencer (1708–1746)
 * Coronet of a British Earl.svg John Spencer, 1st Earl Spencer (1734–1783)
 * Coronet of a British Earl.svg George Spencer, 2nd Earl Spencer (1758–1834)
 * Coronet of a British Earl.svg Frederick Spencer, 4th Earl Spencer (1798–1857)
 * Coronet of a British Earl.svg Charles Spencer, 6th Earl Spencer (1857–1922)
 * Coronet of a British Earl.svg Albert Spencer, 7th Earl Spencer (1892–1975)
 * Coronet of a British Earl.svg John Spencer, 8th Earl Spencer (1924–1992)
 * (25) Coronet of a British Earl.svg Charles Spencer, 9th Earl Spencer (b. 1964)
 * (26) Louis Spencer, Viscount Althorp (b. 1994)
 * (27) Edmund Spencer (b. 2003)
 * George Spencer (1903–1982)
 * George Spencer (1932-2023)
 * Lady Elizabeth Churchill (1687–1714)
 * Lady Anne Egerton (1705–1762)
 * Coronet of a British Earl.svg George Villiers, 4th Earl of Jersey (1735–1805)
 * Coronet of a British Earl.svg George Child Villiers, 5th Earl of Jersey (1773–1859)
 * Coronet of a British Earl.svg George Child Villiers, 6th Earl of Jersey (1808–1859)
 * Coronet of a British Earl.svg Victor Child Villiers, 7th Earl of Jersey (1845–1915)
 * Coronet of a British Earl.svg George Child Villiers, 8th Earl of Jersey (1873–1923)
 * Coronet of a British Earl.svg George Child Villiers, 9th Earl of Jersey (1910–1998)
 * George Child-Villiers, Viscount Villiers (1948–1998)
 * Coronet of a British Earl.svg (?) William Child-Villiers, 10th Earl of Jersey (b. 1976)$2$
 * (?) George Child-Villiers, Viscount Villiers (b. 2015)
 * (?) Jamie Child-Villiers (b. 1994)$3$
 * Edward Child-Villiers (1913–1980)
 * (?) Edward Child-Villiers (b. 1935)
 * (?) Alexander Child-Villiers (b. 1961)
 * (?) Frederick Child-Villiers (b. 1990)
 * (?) William Child-Villiers (b. 2003)
 * (?) George Child-Villiers (b. 1947)

Subsidiary titles
The Duke holds subsidiary titles: Marquess of Blandford (created in 1702 for John Churchill), Earl of Sunderland (created in 1643 for the Spencer family), Earl of Marlborough (created in 1689 for John Churchill), Baron Spencer of Wormleighton (created in 1603 for the Spencer family), and Baron Churchill of Sandridge (created in 1685 for John Churchill), all in the Peerage of England.

The title Marquess of Blandford is used as the courtesy title for the Duke's eldest son and heir. The Duke's eldest son's eldest son can use the courtesy title Earl of Sunderland, and the duke's eldest son's eldest son's eldest son (not necessarily the eldest great-grandson) the title Lord Spencer of Wormleighton (not to be confused with Earl Spencer).

The title of Earl of Marlborough, created for John Churchill in 1689, had previously been created for James Ley, in 1626, becoming extinct in 1679.

Foreign titles
The 1st Duke was honoured with land and titles in the Holy Roman Empire: Emperor Leopold I created him a Prince in 1704, and in 1705, his successor Emperor Joseph I gave him the principality of Mindelheim (once the lordship of the noted soldier Georg von Frundsberg). He was obliged to surrender Mindelheim in 1714 by the Treaty of Utrecht, which returned it to Bavaria. He tried to obtain Nellenburg in Austria in exchange, which at that time was only a county ('Landgrafschaft'), but this failed, partially because Austrian law did not allow for Nellenburg to be converted into a sovereign principality. The 1st Duke's princely title of Mindelheim became extinct either on the return of the land to Bavaria or on his death, as the Empire operated Salic Law, which prevented female succession.

Original arms of the Churchill family
The original arms of Sir Winston Churchill (1620–1688), father of the 1st Duke of Marlborough, were simple and in use by his own father in 1619. The shield was Sable a lion rampant Argent, debruised by a bendlet Gules. The addition of a canton of Saint George (see below) rendered the distinguishing mark of the bendlet unnecessary.

The Churchill crest is blazoned as a lion couchant guardant Argent, supporting with its dexter forepaw a banner Gules, charged with a dexter hand appaumée of the first, staff Or.

In recognition of Sir Winston's services to King Charles I as Captain of the Horse, and his loyalty to King Charles II as a Member of Parliament, he was awarded an augmentation of honour to his arms around 1662. This rare mark of royal favour took the form of a canton of Saint George. At the same time, he was authorised to omit the bendlet, which had served the purpose of distinguishing this branch of the Churchill family from others which bore an undifferenced lion.

Arms of the 1st Duke of Marlborough
Sir Winston's shield and crest were inherited by his son John Churchill, 1st Duke of Marlborough. Minor modifications reflected the bearer's social rise: the helm was now shown in profile and had a closed grille to signify the bearer's rank as a peer, and there were now supporters placed on either side of the shield. They were the mythical Griffin (part lion, part eagle) and Wyvern (a dragon without hind legs). The supporters were derived from the arms of the family of the 1st Duke's mother, Drake of Ash (Argent, a wyvern gules; these arms can be seen on the monument in Musbury Church to Sir Bernard Drake, d.1586).

The motto was Fiel pero desdichado (Spanish for "Faithful but unfortunate"). The 1st Duke was also entitled to a coronet indicating his rank.

When the 1st Duke was made a Prince of the Holy Roman Empire in 1705, two unusual features were added: the Imperial Eagle and a Princely Coronet. His estates in Germany, such as Mindelheim, were represented in his arms by additional quarterings.

Arms of the Spencer-Churchill family
In 1817, the 5th Duke received Royal Licence to place the quarter of Churchill ahead of his paternal arms of Spencer. The shield of the Spencer family arms is: quarterly Argent and Gules, in the second and third quarters a fret Or, over all on a bend Sable three escallops of the first. The Spencer crest is: out of a ducal coronet Or, a griffin's head between two wings expanded Argent, gorged with a collar gemel and armed Gules. Paul Courtenay observes that "It would be normal in these circumstances for the paternal arms (Spencer) to take precedence over the maternal (Churchill), but because the Marlborough dukedom was senior to the Sunderland earldom, the procedure was reversed in this case."

Also in 1817, a further augmentation of honour was added to his armorial achievement. This incorporated the bearings from the standard of the Manor of Woodstock and was borne on an escutcheon, displayed over all in the centre chief point, as follows: Argent a cross of Saint George surmounted by an inescutcheon Azure, charged with three fleurs-de-lys Or, two over one. This inescutcheon represents the royal arms of France.

These quartered arms, incorporating the two augmentations of honour, have been the arms of all subsequent Dukes of Marlborough.

Motto
The motto Fiel pero desdichado is Spanish for 'Faithful but unfortunate'. Desdichado means without happiness or without joy, alluding to the first Duke's father, Winston, who was a royalist and faithful supporter of the king during the English Civil War but was not compensated for his losses after the restoration. Charles II knighted Winston Churchill and other Civil War royalists but did not compensate them for their wartime losses, thereby inducing Winston to adopt the motto. It is unusual for the motto of an Englishman of the era to be in Spanish rather than Latin, and it is not known why this is the case.

Earls of Marlborough, first creation (1626–1679)
The earldom of Marlborough was held by the family of Ley from 1626 to 1679. James Ley, the 1st Earl (c. 1550 – 1629), was lord chief justice of the King’s Bench in Ireland and then in England; he was an English member of parliament and was lord high treasurer from 1624 to 1628. In 1624 he was created Baron Ley and in 1626 Earl of Marlborough. The 3rd earl was his grandson James (1618–1665), a naval officer who was killed in action with the Dutch. James was succeeded by his uncle William, a younger son of the 1st earl, on whose death in 1679 the earldom became extinct.

Earls of Marlborough, second creation (1689)

 * Other titles: Lord Churchill of Eyemouth, in the county of Berwick (Scotland 1682) and Baron Churchill of Sandridge, in the county of Hertford (England 1685)

 * John Churchill, 1st Earl of Marlborough (1650–1722), became Duke of Marlborough in 1702

Dukes of Marlborough (1702)

 * Other titles: Marquess of Blandford (England 1702), Earl of Marlborough, in the county of Wiltshire (En 1689) and Baron Churchill of Sandridge, in the county of Hertford (England 1685)
 * Other titles (1st Duke): Lord Churchill of Eyemouth, in the county of Berwick (Scotland 1682)

 * John Churchill, 1st Duke of Marlborough (1650–1722), soldier and statesman
 * John Churchill, Marquess of Blandford (1686–1703), elder son of the 1st Duke, died unmarried
 * Henrietta Godolphin, 2nd Duchess of Marlborough (1681–1733), eldest daughter of the 1st Duke, succeeded her father by Act of Parliament (1706)
 * William Godolphin, Marquess of Blandford (1700–1731), elder son of the 2nd Duchess, predeceased his mother without issue
 * Anne Spencer, Countess of Sunderland (née Lady Anne Churchill; 1683–1716), second daughter of the 1st Duke, married Charles Spencer, 3rd Earl of Sunderland, predeceased her elder sister, leaving male issue
 * Other titles (3rd Duke onwards): Earl of Sunderland (England 1643) and Baron Spencer of Wormleighton (England 1729)

 * Charles Spencer, 3rd Duke of Marlborough (1706–1758), 5th Earl of Sunderland, second son of Anne Spencer, Countess of Sunderland
 * George Spencer, 4th Duke of Marlborough (1739–1817), elder son of the 3rd Duke
 * George Spencer-Churchill, 5th Duke of Marlborough (1766–1840), elder son of the 4th Duke
 * George Spencer-Churchill, 6th Duke of Marlborough (1793–1857), eldest son of the 5th Duke
 * John Winston Spencer-Churchill, 7th Duke of Marlborough (1822–1883), eldest son of the 6th Duke and paternal grandfather of Winston Churchill
 * George Charles Spencer-Churchill, 8th Duke of Marlborough (1844–1892), eldest son of the 7th Duke
 * Charles Richard John Spencer-Churchill, 9th Duke of Marlborough (1871–1934), only son of the 8th Duke
 * John Albert William Spencer-Churchill, 10th Duke of Marlborough (1897–1972), elder son of the 9th Duke
 * John George Vanderbilt Henry Spencer-Churchill, 11th Duke of Marlborough (1926–2014), elder son of the 10th Duke
 * Charles James Spencer-Churchill, 12th Duke of Marlborough (b. 1955), eldest surviving son of the 11th Duke

The heir apparent to the dukedom is George John Godolphin Spencer-Churchill, Marquess of Blandford (b. 1992), eldest son of the 12th Duke.

Family trees

title: Duke of Marlborough (title)


text:
Talk:Dairy product

Wiki Education Foundation-supported course assignment
This article was the subject of a Wiki Education Foundation-supported course assignment, between 13 February 2019 and 3 May 2019. Further details are available on the course page. Student editor(s): Paigebrazil.

Consumption per capita (150kg/330lb) questionable
Please correct (or confirm?) the per capital consumption of cheese that seems awfully high. (possibly a decimal point math error/order of magnitude typo).

Under consumption patterns:

"High-consumption countries consume more than 150 kilograms (330 lb) per capita per year."

That's all. I hope this post is an acceptable way to bring attention to this. 74.58.197.62 (talk) 19:03, 25 February 2023 (UTC)

Wiki Education assignment: English 102 Section 6
— Assignment last updated by DoctorBeee (talk) 19:54, 11 March 2024 (UTC)

title: Talk:Dairy product