Milestone-Proposal:Universal Serial Bus (USB)

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Docket #:2020-07

This proposal has been submitted for review.

To the proposer’s knowledge, is this achievement subject to litigation? No

Is the achievement you are proposing more than 25 years old? Yes

Is the achievement you are proposing within IEEE’s designated fields as defined by IEEE Bylaw I-104.11, namely: Engineering, Computer Sciences and Information Technology, Physical Sciences, Biological and Medical Sciences, Mathematics, Technical Communications, Education, Management, and Law and Policy. Yes

Did the achievement provide a meaningful benefit for humanity? Yes

Was it of at least regional importance? Yes

Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)? Yes

Has the IEEE Section(s) in which the plaque(s) will be located agreed to arrange the dedication ceremony? Yes

Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated? Yes

Has the owner of the site agreed to have it designated as an IEEE Milestone? Yes

Year or range of years in which the achievement occurred:


Title of the proposed milestone:

Universal Serial Bus (USB), 1996

Plaque citation summarizing the achievement and its significance:

An industry consortium published the first Universal Serial Bus (USB) specification in January 1996. Initially intended to simplify attaching electronic devices to a PC, USB became a very successful low-cost, high-speed interface for home and business use. Its ability to support new device classes and functionalities, including data storage, power delivery, and battery charging, has made USB's cabling, connectors, and logo recognizable worldwide.

200-250 word abstract describing the significance of the technical achievement being proposed, the person(s) involved, historical context, humanitarian and social impact, as well as any possible controversies the advocate might need to review.

IEEE technical societies and technical councils within whose fields of interest the Milestone proposal resides.

In what IEEE section(s) does it reside?


IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:

IEEE Organizational Unit(s) paying for milestone plaque(s):

Unit: Oregon Section
Senior Officer Name: Paulo Vasconcelos

IEEE Organizational Unit(s) arranging the dedication ceremony:

Unit: Oregon
Senior Officer Name: Paulo Vasconcelos

IEEE section(s) monitoring the plaque(s):

IEEE Section: Oregon
IEEE Section Chair name: Paulo Vasconcelos

Milestone proposer(s):

Proposer name: Brian A. Berg
Proposer email: Proposer's email masked to public

Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.

Street address(es) and GPS coordinates in decimal form of the intended milestone plaque site(s):

Intel Corporation, 2111 NE 25th Ave, Hillsboro, OR 97124 (Intel Jones Farm Campus) 45.543941 122.962248

Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.

Please give the address(es) of the plaque site(s) (GPS coordinates if you have them). Also please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need. In the lobby of the Jones Farm Conference Center (JFCC) on the Intel Jones Farm Campus

Are the original buildings extant?


Details of the plaque mounting:

On a wall in the lobby of the JFCC

How is the site protected/secured, and in what ways is it accessible to the public?

There is a security guard, and the lobby is open to the public during normal business hours

Who is the present owner of the site(s)?

Intel Corporation

What is the historical significance of the work (its technological, scientific, or social importance)? If personal names are included in citation, include justification here. (see section 6 of Milestone Guidelines)

The key initial importance of USB was its impact on transforming the task of attaching and removing devices from computers from a process that required technical skills and patience into one that was as easy as inserting or removing a cable – a process dubbed as “Plug and Play.” USB thereby made computers more user friendly, whether it be at home, in an office setting, or in a data center. USB’s popularity led to other uses such charging batteries in cell phones and becoming the power connector for computers. As a result, USB has become ubiquitous on most computerized devices, and its logo and cabling are recognized worldwide.

Expanding the capabilities PC-class computers was difficult before the mid-1990s
Until the mid-1990s, it was difficult for anyone without some technical skills to significantly expand the capabilities of IBM PC-class computers. For the general consumer world, such a task was practical only for “hobbyists.” For the business world, an IT department whose staff could configure and support system reconfigurations or expansions was generally required.

The means by which new hardware could be added to PCs was usually by using one or more of the following: the serial port, the parallel port (which sometimes adhered to the IEEE 488 standard), and an expansion board that was installed in an open slot in the computer’s internal motherboard. For example, adding a new device such as a digital scanner typically required opening up the PC and installing an expansion board that used either SCSI or some proprietary protocol. Such a task could include unscrewing and uncabling some existing components, manipulating jumpers and/or dip switches to configure DMA channels and IRQ request lines, and often much trial and error while having to power the PC on and off each time a change was made before the scanner could operate.

Many of the problems encountered were due to the lack of standard practices amongst the many suppliers in the industry, and thus the difficulty of describing the necessary steps for adding the new hardware because of, for example, the configuration of devices already installed on the PC. As such, adding new hardware and returning the PC to a fully working condition was often a difficult task even for skilled hobbyists and professionals. The non-technical consumer public would either rely on staff at a computer store to undertake such a task, or they would not even consider adding a new device such as a scanner. Retail computer superstore CompUSA reported that their product return rate for scanners was over 30%, and that the impact of these returns resulted in a net loss for the entirety of their scanner sales at that time.

The Plug and Play Standard
An effort called “Plug and Play” (abbreviated as PnP) began in the 1990s as part of an industry-wide effort to allow a PC to automatically self-configure both its hardware and software in order to accommodate the addition of a new device with little or no effort by the user. PnP was intended to be automatically invoked when new hardware was installed inside the PC, but also to accommodate “hot swapping” a device so as to not require the PC to first be powered off. Thus, the computer would automatically recognize any new device, load new software drivers if needed, and allow the newly-connected device to be usable.

PnP was a collection of methods for determining and controlling system resource usage, and thereby required that a PC’s motherboard, system BIOS and peripherals all be PnP-compliant. A number of hardware and software companies developed the PnP standard for the control of all system resources so that changes could be dynamically performed when the computer was booted after a reconfiguration, as well as by plugging or unplugging a device while the computer was running.

ISA PnP in 1993 defined hardware methods for detecting and configuring ISA bus expansion cards, but typically didn’t expect those cards to be reconfigured during normal operation. A document titled “Plug and Play BIOS Specification Version 1.0A” (Media:PnP-BIOS-Specification-V1.0A.pdf) was published on May 5, 1994 jointly by Compaq Computer Corp., Phoenix Technologies, Ltd. and Intel Corp. to define requirements for the system BIOS aspect of PnP. A document titled "Plug and Play ISA Specification Version 1.0a" (Media:PNP-ISA-v1.0a.pdf) was published on the same day jointly by Intel Corp. and Microsoft Corp. to define motherboard and expansion card hardware requirements in support of PnP. Soon thereafter, Intel started shipping motherboards equipped with PnP BIOS and ISA bus plug-in card slots able to support PnP-capable expansion cards.

Released in August 1995, Microsoft’s Windows 95 operating system’s major architectural changes as compared with its Windows 3.1 predecessor were critical to advancing PnP in the industry. Its System Registry worked with a comprehensive scheme of enumerating hardware at boot time, and the ability to dynamically allocate and deallocate resources as hardware was added or removed from a running PC. An essential Windows 95 PnP component was its "Add New Hardware" wizard which recognized when new hardware was attached, and which would guide the user through any steps necessary to allow its use.

This excerpt from p. 1 of the 1999 book USB Design by Example [Hyde 1999] summarizes the issues solved by USB 1.0 and 1.1, whose "High performance" was the Full-speed rate of 12 Mbits/sec.

Intel initiated the efforts that led to USB’s creation
Intel's Ajay Bhatt was an early advocate of replacing the existing serial and parallel interfaces with a single, universal interface that supported hot swapping. Bhatt helped convince Intel of the feasibility of the idea. After initial work on a spec (initially called the “Serial Bus”) had been completed in early 1994, Jim Pappas (who had been working at Digital Equipment Corp., aka DEC) joined Intel and led the effort for this new bus. Intel invited key industry players to join a working group to further develop the spec, and their first meeting was held in May 1994 at Intel’s Jones Farm Campus in Hillsboro, OR.

The attendees brainstormed about which direction to take and which technical skills to recruit for the effort. This meeting was the birth of what was eventually called the Universal Serial Bus, or USB. This effort resulted in seven companies working together to create USB Specification Revision 1.0 (Media:USB_1.0_Specification.pdf) as released on Jan. 15, 1996: Compaq, Digital Equipment Corp. (DEC), the IBM PC Co., Intel, Microsoft, NEC and Northern Telecom (Nortel). USB embraced PnP's self identification and configuration technologies, and required that all USB devices had to be configured before they could be used.

The introductory chapter of this first USB Specification states that the “motivation for the Universal Serial Bus comes from three interrelated considerations” which it describes as “Connection of the PC to the telephone” (due to “the merge of computing and communication” being “the basis for the next generation of productivity applications”), “Ease of use” (the difficulties resultant from the multiplicity of different means by which a device can be attached to a computer, including the serial/parallel ports discussed above, keyboard/mouse/joystick interfaces, and new interfaces created to accommodate new device types), and “Port expansion” (the limited number of ports in computers). Thus, the “lack of a bi-directional, low-cost, low-to-mid speed peripheral bus has held back the creative proliferation of peripherals.”

The Importance of Intel’s Jones Farm Campus
While the first USB specification was being created, most interactions with outside vendors took place during regularly-scheduled conference calls. Outside vendors such as Microsoft often came to meetings at Jones Farm, and face-to-face meetings were generally hosted by various companies elsewhere. However, the Jones Farm Campus became the "epicenter" of this endeavor as hardware and software was being developed and tested collaboratively.

There is a glass conference room at the entrance of the Jones Farm 3 building (JF3) that was unique since it was accessible prior to reaching the security desk, and it had been a private conference room reserved for the most senior Intel executives. This room was allowed to be converted into a lab for a 3-month period, but it ended up being used for over 3 years by nearly every company working in the ever-growing USB industry. Dubbed the USB Product Integration Lab (PIL), it could be occupied by various companies 24 hours a day, even after the lobby was closed. As there were no USB devices, hubs or hosts in the early days, Intel created debug versions of these devices along with software drivers and test tools. All of the original furniture in the PIL was replaced with several lab benches, and every bench was filled with these debugging tools along with test equipment. Companies developing new USB products were able to use the PIL as a test and debug environment while working with Intel USB engineers in order to get USB signaling, packets and transactions operational. The companies using the PIL were often very secretive about the products that they had under development. Until at least 1996, most industry players involved in early development efforts used the PIL to debug their USB products before they went into production. Key to this effort was the availability of the first USB ICs from Intel in 1995.

This excerpt from p. 14 of the 2015 document How USB Became the Most Successful Interface in Computing History discusses the popularity of USB in 1998 around the time of the release of USB 1.1 and Windows 98.

USB played an essential role in transitioning the PC into a consumer-level device
The USB standard was created by the industry to allow the PC to expand beyond just business applications by enabling a consumer-friendly way to add devices to a computer, and also enabling new usage areas such as digital music and digital photography. Essential to USB was a standard connector on the exterior of the computer which allowed any type of USB device to be dynamically plugged into or unplugged from a running computer. Most computers included at least two such connectors, and a USB hub allowed multiple devices to be supported from a single USB connector.

The fact that PnP was an essential aspect of the new Windows 95 architecture allowed the addition of support for USB by way of OEM Service Release (OSR) 2.1, which became available on August 27, 1997. Nearly every industry player, including Microsoft itself, used the USB PIL to debug and validate their products since Windows 95 was the first operating system to support the new USB standard.

USB reached a critical turning point with the June 1998 release of Windows 98 because of its support of a draft version of the USB 1.1 spec. With Windows being the world’s most popular operating system, the number of USB devices on the market began to grow dramatically. In addtion, Apple's iMac (announced in May 1998 and released in August 1998) replaced its normal mouse and keyboard connectors with a pair of USB connectors. USB Specification Revision 1.1 (Media:Usb11.pdf) was released on September 23, 1998.

This excerpt from pp. 10-11 of the 2015 document How USB Became the Most Successful Interface in Computing History discusses the importance of the 40x performance improvement provided by USB 2.0's High-speed transfer rate, and how this was critical for USB's adoption for data storage, digital imaging and communications applications.
Wikimedia image comparing the size of a USB Flash Drive (UFD) with a floppy disk.

USB 2.0 Enabled USB's Huge Commercial Success and Led to the Obsolescence of the Floppy Disk
Jim Pappas was a key Intel employee, and he became the first Chairman of the non-profit USB Implementers Forum (USB-IF) upon its formation in 1995. He had seen USB's ever-increasing popularity after the release of the USB 1.0 and 1.1 specifications, and these standards supported two data rates: 1.5 Mbits/sec (Low-Speed) and 12 Mbits/sec (Full-Speed). Pappas knew that USB could achieve even broader success with a higher data rate. He led the team that developed the USB Specification Revision 2.0 (Media:Usb_20.pdf) which was released on April 27, 2000.

USB 2.0 added a third data rate of High-Speed, whose 480 Mbits/sec speed was a dramatic 40x improvement over the Full-Speed maximum transfer rate of USB 1.0 and USB 1.1. The throughput enabled by High-Speed opened up new markets for data storage, digital imaging and communications products. With the growing popularity of flash memory, the USB Flash Drive (UFD) as introduced in 1999 became a very compelling application of USB 2.0.

The UFD's popularity grew quickly because of its small size, speed, and ever-increasing capacity, and this led to the obsolescence of the floppy disk. Although a floppy drive had been an essential peripheral since the dawn of the personal computing age in the mid-1970s, the UFD's phenomenal success led Dell Computer Corp. to make the floppy drive optional in some of its home PCs starting in early 2003. Every other personal computer manufacturer followed suit in fairly short order, and thus floppy disks became a thing of the past. As such, USB connectors in effect supplanted floppy disk drives since UFDs were so much more versatile.

Ironically, although Apple was not amongst the companies working on the USB standard, Apple's iMac (released in August 1998, as discussed in the previous section) was the first commercial computer to replace the floppy drive with a pair of USB connectors. Apple thus created an immediate demand for a storage device with a USB interface. A floppy drive with a USB interface quickly filled this void, and UFDs helped fill this demand as well when they became available in 1999. This move to USB allowed manufacturers to produce hardware products that were compatible with both PCs and the iMac, and eventually witl all Apple products. Thus, with only software drivers being needed to allow USB products to be operable throughout the industry, the demand for USB devices further accelerated.

Excerpt from Press Release honoring Intel USB inventors.

European Patent Office Honored Intel Inventor Team with Award for USB in 2013
An Intel team of five inventors was honored by the European Patent Office with its 2013 "Non-European Countries" Award for its work on USB as "one of the most important advances in computing since the silicon chip. An industry standard today, USB not only allows users to more easily connect devices to a computer, it also streamlines work for hardware and software developers. It is found in billions of electronic devices all over the world, from webcams to cell phones and memory sticks."

The five recipients were Ajay V. Bhatt, Bala Sudarshan Cadambi, Jeff Morriss, Shaun Knoll, and Shelagh Callahan. These five, along with Puthiya Kottal Nizar, Richard M. Haslam, and Andrew M. Volk, were the inventors of five patents for technology from the early days of the USB standard's development: US 5,615,404 Media:US5615404.pdf, US 5,623,610 Media:US5623610.pdf, US 5,694,555 Media:US5694555.pdf, US 5,742,847 Media:US5742847.pdf, and US 5,909,556 Media:US5909556.pdf.

What obstacles (technical, political, geographic) needed to be overcome?

Technical Obstacles
USB’s most significant technical challenge was containing costs. The USB design target included the mouse, the single most common pointing device at the time. Microsoft disclosed that the entire electronics budget for their optical mouse was only 50 cents. Using the mouse as the baseline, this design target set up a series of challenges regarding how to keep the design simple and inexpensive, while still allowing it to expand into areas such as imaging, storage, and synchronous applications such as music and digital telephony.

A second significant technical obstacle arose due to the desire to minimize cost. The challenge was how to accomplish all the desired communication and control functionalities using only a single differential signaling pair - essentially one logical wire. In comparison, other popular cabled connections of the time used many wires, with wires dedicated to special signals such as interrupts.

Broad Acceptance Obstacle
USB faced a critical obstacle for its acceptance and success in the marketplace. The industry recognized the need for a simplified low-cost interface that used a single connector to support a variety of hot-swappable devices, and USB’s main competition in achieving this was IEEE 1394/FireWire and ACCESS.bus:
IEEE 1394/FireWire:
  o Like USB, it included both power and data on its cabling, but IEEE 1394 provided more power
  o Like USB, it supported hot-swapping (and hence could potentially be plug-and-play)
  o USB had significantly lower cost than IEEE 1394 because of its simplicity (use of a host master) as compared with 1394’s symmetric and more complex peer-to-peer architecture, as well as because its initial design was as a lower-performance interface than 1394
  o While Steve Jobs was receiving a royalty from PC OEMs of $1 for each IEEE 1394 port, Intel was adding USB to its own processor chipset. Since the resultant PC OEM cost of adding USB was thus little more than the cost of adding a pair of USB connectors, the incentive to include 1394 ports in PCs was greatly diminished.
  o As a result, USB connectors were included on most new PCs near the time of USB’s 1996 introduction, and these USB connectors were supported in Microsoft Windows starting in 1997
  o As USB was thus available on all of the newer PCs, IEEE 1394 was marginalized to a higher-priced echelon of the consumer electronics market
Apple Desktop Bus (ADB):
  o Proprietary to Apple, and so never a direct USB competitor
  o Only ever used for low-speed devices such as keyboards and mice
  o Did not support hot swapping
  o Introduced on the Apple IIGS in 1986, and included in Apple products until the early 2000s
  o Used on some NeXT computers, and some third-party computers
  o Apple replaced ADB with USB starting with the 1998 iMac (which also included IEEE 1394/FireWire)
ACCESS.bus (A.b)
  o Created by Philips and DEC for the PC as a way to reproduce much of what ADB offered
  o Supported hot swapping, but its 10 kbit/sec and 100 kbit/sec speeds were much slower than USB’s speeds of 1.5 Mbits/sec and 12 Mbits/sec
  o ACCESS.bus Industry Group (ABIG) was formed in 1993, and included Microsoft and DEC
  o Interest waned with Intel’s backing of USB, leaving Philips as the prime supporter
  o ACCESS.bus thus never achieved widespread use

In [Axelson 2001], ACCESS.bus is discussed on p. 17, concluding with "ACCESS.bus never caught on with PCs, but is still used in other applications, including smart battery control." A section titled "USB versus IEEE-1394" on pp. 19-20 notes that 1394 "is a more flexible interface, but the peripherals’ electronics are more complex and expensive." These statements were written in 2001, and both ACCESS.bus and IEEE-1394 have fallen by the wayside since that time in the wake of USB's huge success worldwide.

Political Obstacle
A “political” obstacle occurred once it was obvious that USB had broad industry support. A wide variety of requests started to arrive from adjacent markets that wanted to utilize the ubiquity and low cost expected from USB, including numerous requests for additional features which would have expanded the design of USB well beyond its original simple objectives. Examples include (1) fully symmetric and autonomous operation so that devices could communicate even if the PC was powered off, (2) long range cable lengths of up to 1 km, and (3) waterproof connectors for underwater dive computers.

What features set this work apart from similar achievements?

In recognition of the 20th anniversary since work on the USB standard started ramping up, Intel produced How USB Became the Most Successful Interface in Computing History Media:Usb-two-decades-of-plug-and-play-article.pdf in 2015. This document details the history of USB and the reasons for its tremendous success, including how the USB Implementers Forum (USB-IF) as formed in 1995 has ensured industry interoperability of USB hardware and software by way of compliance testing and logo licensing, and whose website maintains information including copies of key USB documents.

USB’s Asymmetric Design Allowed for Simplicity and Lower Cost
USB was based on a strategic design choice of being asymmetric to take advantage of the fact that the host side interface would have the extensive resources available to a full PC, thus allowing design choices for the device side of the wire to be relatively simple. This decision was hugely beneficial as it (1) allowed the capabilities of a USB device to range from ultra-simplistic to highly sophisticated, (2) differentiated USB from the symmetric design and resultant higher cost of IEEE 1394/FireWire, and (3) led to a broad range of types of USB devices being possible, and which was ever-expanding.

In [Garney 1998], this point is discussed on p. 3, "The companies developing the USB bus consciously chose to make the bus definition asymmetric, i.e., the cost/complexity of the host controller would be greater than that of a device. This was done so devices would be easier to create. Even though the host controller was slightly more complicated and expensive, it was expected that it could easily be incorporated in the standard silicon included on every PC." John Garney is lead inventor of numerous patents reading on USB, including US 6,546,018 as filed in 1999, and which is a base USB 2.0 patent describing a transaction translator hub for improving bandwidth Media:US6546018(Garney,et-al).pdf.

USB’s Inclusion of Power in Its Cabling
The early decision to supply power to attached devices was quite controversial as no widely-used computer interface provided power at that time. The main reason for this was to accommodate devices such as keyboards and mice, which could not have a separate power supply connection. Other devices were also envisioned that could be fully powered from the bus.

A big surprise was when Logitech completely re-engineered its prototype portable sheet scanner (including the use of new motors) to operate within USB’s 2.5 Watt limit. The inclusion of power often precluded the need for a wall plug power adapter (often called a “wall wart”), and this also had a huge positive impact since it allowed a single cable to attach a wide variety of devices to a PC.

USB’s Inclusion of Power Allowed it to Eventually Function as a Charger
USB’s inclusion of power proved to be hugely beneficial to USB’s success in ways that were far beyond what anyone had envisioned in the mid-1990s. Starting in around 2006, a number of cell phone suppliers (most notably Motorola and Nokia) developed an ancillary specification for the Micro-USB connector specification that would better serve the mobile phone market. In around 2007, Qualcomm and Nokia led an effort to develop the Battery Charging Specification to enable increasing the 5-volt supply current beyond 500 mA when used for mobile phone charging. Thus, USB ports could offer up to 1.5A (7.5 Watts) when enabled for charging using a standardized discovery technique based on the termination of the USB 2.0 data bus pins, and this scheme served the mobile phone industry for several years.

Starting in 2012, competitive pressures in the explosively expanding cell phone market led to interoperability issues with the standard USB Micro-B connector as proprietary charging techniques that pushed the power boundaries beyond the USB standard's 5V @ 1.5A limitation came into use. One example is Qualcomm’s Quick Charge (QC) technology.

With the introduction of the 2014 specifications for the USB Type-C® connector and USB Power Delivery, delivery of up to 100W of power over the USB Type-C® connector, a fully standardized USB fixed voltage charging solution tailored to a broad range of applications became available. In 2017, USB Power Delivery was enhanced to add dynamic programmable voltage and current modes that targeted newer fast charging methods for mobile phones.

USB’s Simple Design Was Essential to Its Success
The USB standard purposefully defined several standard device classes including mass storage, audio, video and communication. These device classes allowed OS vendors to provide standardized device drivers, and avoided having every device vendor provide their own driver. This further reduced errors in the field due to incorrectly implemented device drivers, and these have proved adequate to support a broad range of device types. It was felt that if USB was allowed to increase in complexity, a lack of focus would prevent it from remaining low-cost and achieving widespread usage. As such, the standard was created with the intent that the feature set and cost were in line with the ability of computer manufacturers to provide USB in every platform, and as part of every base configuration – and this intent has been proven in the marketplace.

This simple design allowed USB to address its targeted applications (which initially were peripherals attached to PC-class computers), and also allowed the vast majority of other device types to find a way to make USB work. Indeed, the different usages of USB have been ever-increasing over the years. Thus, while initially created to ease the difficulties of connecting new hardware to PC-class computers, USB’s simple design philosophy has led to its adoption throughout the computer, consumer electronics and mobile communications industries, into automobiles and industrial automation applications, and for power applications such as recharging batteries as well as providing primary power to computers and many other kinds of devices.

USB’s Universality
There is no other computerized interface in the world that has had anything approaching USB’s widespread acceptance – it is truly ubiquitous, and it has seen a continual increase in usage in an ever-broadening range of product categories since its 1996 introduction. In 2006 alone, over 2 billion USB devices were shipped.

USB Implementers Forum (USB-IF)
Much of USB’s success is due to its having been designed by a broad industry coalition. As key players in that coalition were writing the USB 1.0 Specification, they created the USB Implementers Forum (USB-IF) in 1995 as a nonprofit organization, and whose main activities have been the promotion and marketing of USB, the creation and maintenance of USB ancillary standard specifications, and running a compliance program to ensure adherence to these specifications. Devices proven to comply with the USB-IF certified testing protocol can be sold with a "USB Certified" logo.

The USB “trident” logo

The USB-IF developed its trademark-protected USB "trident" logo as the USB 1.0 Specification was being written. The inclusion of this logo on cabling and adjacent to connectors has led to it becoming USB’s most universally recognized symbol. The different shapes at the tips of the trident’s three prongs represent the multiple device types able to be supported by USB, and on a single port.

USB cables with Type A (above) and Micro-B (below) plugs, each bearing a “trident” logo

USB Timeline
May 1994: Intel invited representatives from major industry players to a meeting at the Intel Jones Farm campus to discuss “Serial Bus,” a new serial protocol that Intel proposed to replace the antiquated serial and parallel interfaces that were then standard on PC class computers. This bus was eventually given the name Universal Serial Bus, or USB.
Sept. 1995: USB was introduced to an industry gathering of about 700 at the Fairmont Hotel in San Jose, CA. When Jim Pappas was introduced, he walked from the back of the room to the stage while dragging behind him a large swath of cables with mice, keyboards and other peripherals attached. He started his keynote address by saying that “all of this can be replaced by just one of these” while holding up a single USB Type A connector. By the time of this event, 160 companies had registered for USB Vendor IDs.
Jan. 15, 1996: Revision 1.0 of the USB Specification as created by seven key industry players (Compaq, Digital Equipment Corporation (DEC), the IBM PC Co., Intel, Microsoft, NEC and Northern Telecom (Nortel)) was made public. It supported speeds of 1.5 Mbits/sec and 12 Mbits/sec. (Media:USB_1.0_Specification.pdf)
August 27, 1997: Windows 95 OEM Service Release (OSR) 2.1 was released with support for USB, and over 1100 companies had registered for USB Vendor IDs around this timeframe.
June 25, 1998: Windows 98 was released with support for a draft version of the USB 1.1 spec.
August 15, 1998: the Apple iMac G3 was released without an integrated floppy drive, but with USB 1.1 support for a pair of USB connectors able to support devices including a keyboard and mouse, and with industry support for a floppy drive.
Sept. 23, 1998: Revision 1.1 of the USB Specification was released with various embellishments and clarifications. (Media:Usb11.pdf)
April 27, 2000: Revision 2.0 of the USB Specification was released, which added high-speed mode @ 480 Mbits/sec (a 40x improvement). (Media:Usb_20.pdf)
Nov. 12, 2008: Revision 3.0 of the USB Specification was released, which added SuperSpeed mode @ 5 Gbits/sec (an over 10x improvement).
July 26, 2013: Revision 3.1 of the USB Specification was released, which added SuperSpeedPlus @ 10 Gbits/sec (a 2x improvement).
August 11, 2014: Revision 1.0 of the USB Type-C® Specification was released, which introduced the USB Type-C flippable and reversable connector.
August 11, 2014: Revision 2.0 of the USB Power Delivery Specification was released, which enabled support of up to 100W of power over the USB Type-C® connector.
January 12, 2017: Revision 3.0 (V1.1) of the USB Power Delivery Specification was released, which enabled support of Programmable Power Supply (PPS) to enable mobile device fast charging.
Sept. 22, 2017: Revision 3.2 of the USB Specification was released, which added a 2nd data lane for a 2x improvement.
August 29, 2019: the USB4™ Specification was released, which expanded data transfer modes, including tunneling.
August 2019: Release 2.0 of the USB Type-C® Specification was released, which added support for USB4™.
August 2019: Revision 3.0 (V2.0) of the USB Power Delivery Specification was released, which added support for USB4™.

Supporting texts and citations to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or chapters in scholarly books. 'Scholarly' is defined as peer-reviewed, with references, and published. You must supply the texts or excerpts themselves, not just the references. At least one of the references must be from a scholarly book or journal article. All supporting materials must be in English, or accompanied by an English translation.

Supporting materials (supported formats: GIF, JPEG, PNG, PDF, DOC): All supporting materials must be in English, or if not in English, accompanied by an English translation. You must supply the texts or excerpts themselves, not just the references. For documents that are copyright-encumbered, or which you do not have rights to post, email the documents themselves to Please see the Milestone Program Guidelines for more information.

  • Plug and Play BIOS Specification Version 1.0A of May 5, 1994 Media:PnP-BIOS-Specification-V1.0A.pdf
  • Plug and Play ISA Specification Version 1.0A of May 5, 1994 Media:PNP-ISA-v1.0a.pdf
  • USB 1.0: USB Specification Revision 1.0 of January 15, 1996 Media:USB_1.0_Specification.pdf
  • USB 1.1: USB Specification Revision 1.1 of September 23, 1998 Media:Usb11.pdf
  • USB 2.0: USB Specification Revision 2.0 of April 27, 2000 Media:Usb_20.pdf
  • How USB Became the Most Successful Interface in Computing History Media:Usb-two-decades-of-plug-and-play-article.pdf
  • [Garney 1998] USB Hardware & Software by John Garney, Ed Solari, Shelagh Callahan, Kosar Jaff, and Brad Hosler, (c) 1998: excerpt
  • [Axelson 2001] USB Complete: Everything You Need to Develop Custom USB Peripherals: Second Edition by Jan Axelson, (c) 2001: excerpt
  • [Hyde 1999] USB Design by Example: A Practical Guide to Building I/O Devices by John Hyde, (c) 1999: excerpt
  • European Inventor Award 2013 for Non-European Countries given to Intel Team of 5 for creating and developing USB technology. Media:EuropeanInventorAward.pdf
  • US 5,615,404: patent for technology from the early days of the USB standard's development Media:US5615404.pdf
  • US 5,623,610: patent for technology from the early days of the USB standard's development Media:US5623610.pdf
  • US 5,694,555: patent for technology from the early days of the USB standard's development Media:US5694555.pdf
  • US 5,742,847: patent for technology from the early days of the USB standard's development Media:US5742847.pdf
  • US 5,909,556: patent for technology from the early days of the USB standard's development Media:US5909556.pdf
  • US 6,546,018: patent whose application can provide a performance improvement for USB, with John I. Garney as lead inventor Media:US6546018(Garney,et-al).pdf

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