University of Maryland
Trace Research & Development Center


Boy in wheelchair using sliding hand-piece to point to letters on an aluminum communication board wired to a typewriter.

Ludell tries out his first Autocom prototype – made with military surplus parts

The Trace R&D Center has been a leader in the field of Information and Communication Technology for 49 years, and in 2021, will be celebrating its 50th anniversary. By contributing to cutting-edge industry and policy standards, as well as by innovating through research and development, Trace has helped millions of people interact with the world using common, everyday devices like telephones and computers.

Trace researched and developed tools and accessibility features are now found in billions of devices used by people with disabilities every day internationally including every computer and mobile device using Windows, MacOS, iOS, and Android operating systems, and are incorporated into every accessibility standard internationally.

The Trace R&D Center was originally formed in 1971 to address the communication needs of people who are nonspeaking and have severe disabilities. The Center was an early leader and innovator in the field that came to be known as “augmentative communication” (a term first coined by the Trace Center), co-founding the Waisman Center’s Communication Aids & Systems Clinic (CASC) at the University of Wisconsin-Madison.

Picture of software on an Apple IIe computer

Early writing program on an Apple IIe

As the personal computer emerged, the Trace Center became a leader in making computers accessible to people with all types of disabilities. In 1984, the Center served as a coordinator for the nationwide Industry-Government Initiative on Computer Accessibility. The computer design guidelines developed through this effort were used as the basis for many industry guidelines and accessibility standards.

During the 1980s and 1990s, the Trace Center worked directly with the computer companies to integrate disability access features into their standard, mass-market products. As a result of this work, disability access features are incorporated directly into most operating systems and environments today.

As technology became more pervasive in the workplace, education, entertainment, and daily living, Trace’s research and development focused on universal design of information and communication technologies, so that they are more accessible and usable by elders and people with disabilities.

Trace developed the first set of accessibility guidelines for Web content, as well as the Unified Web Access Guidelines, which became the basis for the World Wide Web Consortium’s Web Content Accessibility Guidelines 1.0.

Man standing next to a seated blind person using a EZ Access to access a touchscreen computer

Director Gregg Vanderheiden looks on as fellow Trace Center member Neal Ewers operates IBM Kiosk with EZ Access.

The Center’s EZ Access® techniques have been implemented directly in public information systems and have influenced the development of more accessible ATMs, electronic voting systems, and phones.

The Trace Center developed the accessibility features like Sticky Keys and Screen Magnification, and worked with Microsoft, Apple, and others to build these features into Windows, Mac, and Linux operating systems.

The Trace Center moved to the University of Maryland in 2016, joining the College of Information Studies, and broadening its research and development work through new partnerships and collaborations. In 2021, the Trace Center will celebrate its 50th anniversary.

Here are some of the key success stories from the 50 years of the Trace Center:

The purpose of this page is to briefly describe some of the contributions of Trace R&D Center researchers and engineers over the years.

Auto-Com P – First Portable User Programmable and Correctable Communication Aid

The Auto-com was the first portable communication aid that allowed the user to program their own vocabulary and sentences. It also allowed them to correct their output before printing it on the built-in or external printer. Forty units were distributed nationally by the Trace Center in a cost-recovery program. It was then commercially transferred to Tele-Sensory Systems.

TRINE – First portable communication writing and computer access aid

The TRINE, based on a small HX20 computer, provided multiple innovations including providing the first integrated communication, writing, and computer access interface. Its modular approach allowed different versions of the product to be offered including different versions for keyboard, switch (scan), and head pointing users. The built-in notebook functionality and special features allowed use of the TRINE interfaces to control computers transparently. It was commercially transferred simultaneously to both Adaptive Communications Systems and Words Plus.

Simple Electronic Transducer standard (SET)

In the 1970s there were 15 vendors distributing communication control devices, no two of which even accidentally used the same connector and printouts. Under funding from the National Science Foundation, Trace Center developed standards for simple electronic transducer (single and dual switches, etc) and worked with the vendors to change their products so as to allow interfaces between companies to be interchangeable (something not viewed as being necessarily to their benefit). With the leadership of key vendors, we were able to move the field to the use of the common mono and stereo eighth-inch (3.5mm) phone plugs that are now ubiquitously used in AAC, computer access, and environmental control.

Keyboard Emulating Interface standard (KEI)

The Trace Center pioneered the concept in the late 70s of using one computer or device to control another in a fashion that made input from these adaptive devices indistinguishable from input coming from the standard keyboard of the target computer. This was formalized into the Keyboard Emulating Interface standard, which was adopted as the standard and used by the Adaptive Firmware Card from Adaptive Peripherals Incorporated, the Keyboard Emulating Interface from Prentke Romich and in several augmentative communication aids. (See also GIDEI and SerialKeys for further uses of this standard.)

Portable DecTalk – First “portable” (wheelchair mountable) synthesizer

Working with the Digital Equipment Corporation (DEC) we developed a version of the DecTalk (then designed to only run on AC power) that could work off batteries and could be mounted on the back of a wheelchair. This required modification to the main circuitry of the DecTalk system board and firmware to allow this high power device to do instant and silent startup up and shut down between uses. Transferred to Digital Equipment Corporation (DEC), this was the first portable speech output device for disability.

Ten Branch, QuickKey and SpeedKey

Ten Branch, a simple acceleration routine for computers and communications aids, was developed by the Trace Center and commercially transferred to Words Plus. Variations of it have also appeared in products from many other companies. QuickKey/SpeedKey is an abbreviation expansion program developed by Trace to provide accelerated input speeds. This software was distributed free from the Trace Center. The techniques introduced in this software are in common use today. The program itself was known to be still in use as late as 2004.


StickyKeys is a program that allows individuals with one finger or a head stick, etc. to be able to successfully type, press multiple keys “simultaneously” including Shift, Control, Alt, etc. It was first developed for DOS and then early Windows programs. In 1987 it was transferred to Apple Computer who built it directly into the MacOS and later IIgs and IIe. Trace built it into the Trace Access Pack for Windows 3.0 that Microsoft distributed on its supplemental driver disk. In 1991 Trace created ACCESSDOS for IBM that contained StickyKeys and 7 other features. StickyKeys was also built into OS/2 v2 and X Windows vX11,R6, and subsequent Unix based systems. In 1995 Microsoft licensed StickyKeys from the Trace Center and included it as a standard part of Windows 95 and all subsequent versions of Windows. It has now been released into the public domain and is included in several international standards.


MouseKeys allows individuals to be able to control the mouse from keyboard keys. It followed StickyKeys by a year but followed the same trajectory of commercial transfer as StickyKeys above, including adoption, licensing, and release, and can be found in every copy of MacOS, Windows and other operating systems. It is also widely cited in non-disability related user manuals particularly graphic programs because of the added control it provides over positioning as compared to using the mouse.

Long Range High Resolution Optical Head Pointer (LROP)

The LROP allowed individuals with control only of their head to be able to control computers. It was patented in 1986 and commercially transferred to Words Plus.

One Screen

One Screen, a “terminate-and-stay-resident” program provided a full screen keyboard and transparent computer access with a single computer. It was successfully transferred to Words Plus and allowed people using head pointing to use the same screen for both input and output rather than needing two computers as with previous systems. This was the first non-screen reader program to work simultaneously with mainstream software.

The Trace Resource Book

The Trace Center compiled a book listing all of the internationally known communication, interface and (in later editions) computer access products, with pictures and descriptions provided. This was successfully published and it continued with periodic revisions by Trace for 10 years. It then was converted into electronic form and merged with ABLEDATA (see ABLEDATA).


The Trace Center merged its data with the ABLEDATA database of 20,000 existent technologies and then developed Hyper-ABLEDATA, a HyperCard version of the database that was cross-disability accessible and extraordinarily simple to use. It was so successful that many clinical programs purchased a Macintosh simply to run this one program.


After much work, a method was found to replicate much of the friendliness of Hyper-ABLEDATA in a DOS based program that could run in 640k of memory, including space for screen readers. The Hyper-ABLEDATA CD was then mastered to boot on either Macintosh or DOS computers. This dual version continued up until we migrated ABLEDATA to the Web in the 1990s.


Continuing our work with ABLEDATA originator Marian Hall, the Trace Created the first version of ABLEDATA that was freely available to everyone via the web. This version included all 20,000+ records including pictures, descriptions, do-it-yourself entries and both active and discontinued products.

Service Delivery Directory

To support information and referral personnel, and give them a better mechanism for sharing information and locating resources, a service delivery directory was developed that could run graphically both on Macintoshes and Windows. It allowed personnel to enter the types of services desired and any zip code and it would provide a map (and text listing) showing the location of all of the different possible service providers in order by distance from the client. This directory was added to the CONET CD along with the ABLEDATA information and distributed nationally. About a dozen states and 3 national programs used the SDD for their data.


SlowKeys slows down keyboard response and allows some individuals with cerebral palsy and other disorders with choreatic movements to be able to use the standard keyboard. Developed in 1990 it was commercially transferred to IBM for ACCESSDOS, to the MacOS, and to Windows.


BounceKeys allows individuals with tremor to be able to use keyboards without accidental double strokes. It was also developed in 1990 and transferred first via Trace Access Pack for Windows 3.0 and then to IBM in ACCESSDOS. It was built in as a standard feature in the Windows operating system starting with Windows 95.


ToggleKeys provides an auditory indication of the status of the locking keys on a keyboard for individuals who cannot see. It was also developed in 1990 and transferred first via Trace Access Pack for Windows 3.0 and then to IBM in ACCESSDOS. It was built in as a standard feature in the Windows operating system starting with Windows 95.


SoundSentry is designed for individuals who are hard of hearing or deaf. SoundSentry monitors the speaker drivers and provides a visual indication any time a sound is created. SoundSentry was first introduced under the name ShowSounds. It followed the same adoption pattern as BounceKeys and ToggleKeys.

ShowSounds, Show Captions

ShowSounds is a more advanced form of SoundSentry. When it was developed, it assumed the name ShowSounds and the older version was renamed SoundSentry. ShowSounds consist of a system level flag which could be used to control a wide variety of different types of features for individuals who are deaf including indicators of sound, automatic turn down of captions, etc. The first appearance of it was in Windows 95.

General Input Device Emulating Interface standard (GIDEI)

As mice came into common use in computer systems the Keyboard Emulating Interface standard was extended to provide coverage for mice and other devices. The expanded standard was titled the General Input Device Emulating Interface (GIDEI) standard. This GIDEI standard was commercially implemented in adaptive devices such as the Trace Transparent Access Module (TTAM) from Prentke Romich, and was built into the Windows operating systems as (SerialKeys) starting with Windows 95.

Trace Transparent Access Modular (TTAM)

TTAM was developed to provide special input systems with the ability to transparently control mainstream computers and operating systems. The TTAM supported IBM PC computers, Macintosh computers and other computers running the operating systems in existence at that time (1990) including DOS, Windows, OS/2, AIX, UNIX, Mac OS, AUX, Pro-DOS and GS/OS. The TTAM was commercially transferred to Prentke Romich and Adaptive Communication Systems and was still in use 15 years later.

Disability Access Committee for X (DACX)

The Trace Center coordinated an industry-consumer-researcher working group, which developed a set of access features for the X-Window System used on UNIX. It resulted in a number of access features based on the Trace Center work described above. These have also evolved into modern UNIX and Linux based operating systems.

Serial Wheelchair Control Interface Standard

This standard was developed to create a common protocol for the connection of communication aids and control devices to wheelchairs. Manufacturers became interested in expanding the number of devices that could be connected and used to control different wheelchairs. This standard was picked up by ISO/TC 173/SC1 WG7 and subsequently evolved into a more sophisticated standard called the M3S standard and was implemented in several control devices for wheelchairs.


SerialKeys is the name given to the software that implements the Trace Center’s GIDEI keyboard and mouse emulating standard. SerialKeys allows users to connect special communication and control aids to the serial port of a computer, and send in signals that will be interpreted as standard keyboard and mouse input by the computer. SerialKeys was first transferred to industry in hardware as part of the Trace Transparent Access Module (TTAM). It was part of the Trace Access Pack for Windows 3.0, IBM’s ACCESSDOS, and Microsoft Windows.

EZ Access 1

A package of accessibility strategies for touch screen kiosks was developed and dubbed “EZ Access.” Its first commercial transfer was to public service kiosks located in the Mall of America and other locations in Minnesota. (See EZ Access 2, below.)

Wireless Remote Console Communication Protocol

To facilitate the connection of assistive technologies to mainstream products, a wireless remote communication protocol was developed in connection with the RDA industry consortium. The Trace Center worked with IBM and other groups to evolve this work into the universal remote console standards by ANSI and ISO/IEC (ISO/IEC-25752).

Cross disability accessible electronic voting prototype

The Trace Center developed a series of voting prototypes starting in 1999. The prototypes were highlighted in demonstrations both on Capitol Hill and the White House as well as in Steve Balmer’s keynote speech at FOSE where it was demonstrated. Features from the prototypes have been commercially transferred to Elections Systems and Software (ES&S) voting systems and other voting systems.

First cross disability accessible web kiosk

Partnering with NCR and Productivity Works, a cross disability accessibility web kiosk was created. It was highlighted in the Smithsonian exhibit on disability rights. Other Web kiosks using EZ access included the World War II and Korean War Memorials in Washington DC.

EZ Access 2

An advanced version of EZ Access was developed that eliminated the need for multiple different accessibility modes by creating a single hybrid approach. This new cross-disability mode-less version of EZ Access has been transferred to multiple companies. It is present in 20,000 automated postal systems, all of the latest generation of Amtrak ticketing machines, Phoenix Sky Harbor airport and IBM’s airport and hotel check-in kiosk designs, and Homeland Security GOES passport control kiosks throughout the country, as some examples.

Viking cross disability building security and door control system

Working with Viking Industries in Wisconsin and Smith-Kettlewell Institute in California, the Trace Center developed a cross-disability accessible entrance intercom and door control system, which is now deployed in public housing complex in California. The system is accessible to people with manipulation, vision, and hearing disabilities.

Cross disability accessible ATM

Trace Center developed a prototype cross-disability accessible ATM as well as worked with ATM vendors, banks, consumers and the American Bankers Association to address accessibility concerns. Over 60,000 talking ATMs can be linked directly back to the efforts of the Trace Center working with the disability community around this issue.

T-Trans – Locally Editable Remote Transcription

Under funding from the National Science Foundation, the Trace Center developed the first locally editable remote transcription technology. The local editing capability allows remote transcription to be used for the first time with scientific and other conferences where transcriptionists may not be familiar with the terminology. Any local participant can correct errors, names etc, on the fly. The system was used with NSF’s Access Grid. This was later updated with new web technologies and released as open source Consumer Caption Correction software. This was used by Telecommunication for the Deaf and Hard of Hearing (TDI) and IDEAL Group in creating their uCaption service.

Trace Center Ideas Browser

This is the first online design tool to assist product designers in making mass-market products cross-disability accessible. This free tool provided access to techniques and strategies that are compiled from over 1,000 individual guidelines.

MAGPie Free Captioning Tool

The Trace Center secured funding to develop a free captioning tool. When Trace consulted WGBH’s National Center on Accessible Media as part of development, it found that NCAM was interested in doing such a tool itself. We figured they would be better positioned to do and distribute such a tool, so, with the funding agency’s permission – Trace sent the funds to NCAM who developed the tool and dubbed it MAGPie by NCAM. It is now available from them. MAGPie has now evolved into the WGBH Caption and Description Editing Tool (CADET).

A-Prompt Web Accessibility Verifier Tool

This tool, developed by the University of Toronto’s Adaptive Technology Resource Center, was also supported through the Trace Center’s accessible tool development program for the Web. Other tools supported in their early stages by Trace were the Accessibility Wizard, developed by the University of Illinois, and improvements in the “Bobby” web accessibility and verifier tool.

Photosensitive Epilepsy Analysis Tool (PEAT)

In order to make it practical to use the new W3C Web Content Accessibility Guidelines (WCAG), the Trace Center, in conjunction with Dr. Graham Harding and Cambridge Research Systems, developed a new free web tool for evaluating Web content and software. Previously, the only tool capable of doing the analysis cost approximately $30,000, which put it beyond the reach of most web authors or evaluators. PEAT is now available as a free tool and has enabled more flexible accessibility guidelines as a result. It is cited as the test tool WCAG, Section 508 and the European accessibility standard EN 301 549.

Color Contrast Analyser

To facilitate evaluation, adoption and use of quantitative contrast measures in WCAG, the Trace Center worked with Web tool developers to ensure that free evaluation tools were available. These include tools that can evaluate all of the text on the page at once, and an eyedropper-like tool that provides instant evaluation and pass/fail indication of any two locations. These tools are now widely available and being incorporated into other tool sets, including accessibility toolbars for common browsers. It has been ‘commercially’ transferred to The Paciello Group who makes it available free of charge.

AOL Real Time Text/Instant Messaging

The Trace Center and its partner, Gallaudet University, have worked with AOL to implement RERC-developed hybrid real time text/instant messaging capability. This gave the AOL IM client real time text as a standard feature, allowing individuals who are deaf to carry out real-time conversation using AIM. Since AIM is used by several IP relay operators, this feature has instantly promulgated to the relays, facilitating real-time speech and text translator work of the operators.

Real Time Text CODECs

To support text conversation in next generation telecommunication systems, the RERC has developed a number of open source CODECs that can be used to add text to Voice over IP (VoIP) systems. In addition, Trace worked with one of the major VoIP reference platform manufacturers, and real-time text is now available as a standard component in their reference design. A VoIP phone manufacturer is also releasing mainstream phones with native real-time text capability based on these CODECs.

Trace Center and Accessibility Guidelines

The Trace Center has long been a focus and resource for work on accessibility design guidelines. Most of the early accessibility guidelines inside information and communication technology companies were developed either by or in conjunction with the Trace Center.

Trace Center Consumer Access Guidelines

These were the first cross-disability access guidelines that sought to bring together input from multiple researchers and publications and combine it with new original guidance based upon the work at Trace. Their impact on other guidelines can be seen through the similar and often verbatim provision in other access guidelines. They’ve also been used in developing industry guidelines and in the Handbook of Human Factors and Ergonomics (Gavriel Salvendy, Ed.).

Apple Accessibility Guidelines and Intern Report Cards

All of the initial accessibility guidelines and accessibility “report cards” at Apple Computer were developed by or in collaboration with the Trace Center.

Trace Center Software Accessibility Guidelines

These guidelines, first developed by the Trace Center for the Information Technology Foundation, were later adopted by Microsoft and distributed to all of its Windows developers as part of their developer’s kit. The guidelines were also used as the starting point for the development of Microsoft’s own internal Windows-specific accessibility design guidelines.

IBM Accessibility Guidelines

Based upon our work, the Trace Center was commissioned in 1987-88 to develop the first set of internal IBM accessibility guidelines, which were then used by IBM’s developers and engineers to increase the accessibility of their mainstream products.

Microsoft Intel PC system guidelines

In the 1990s, Microsoft and Intel jointly put out the “PC System design guidelines”, an annual reference which was used as the industry blueprint for the design of desktop and portable computers. It became the bible for the industry, since conformance to the guidelines was required for any “Windows Ready” computers. Trace was asked to add accessibility information to all of the relevant chapters in 1998. In 1999, a special chapter was added to bring the information together.

First Web Accessibility Guidelines

The Trace Center developed the first set of web accessibility guidelines after the second Worldwide Web conference (WWW2). The guidelines were released in January 1995.

Unified Web Content Accessibility Guidelines

After a proliferation of web accessibility guidelines flooded and confused the web development community, the Trace Center gathered other key accessibility guidelines authors and created the Unified Web Guidelines. Version 8 of these guidelines was adopted in 1998 by the World Wide Web Consortium and used as the foundation for developing the current W3C’s Web Content Accessibility Guidelines version 1.0, released in 1999. The Trace Center Director and Chuck Letourneau were asked to co-chair and Trace Center alumnus Wendy Chisholm (then of the W3C) was the staff liaison and a co-editor.

The JAVA Accessibility Report

SUN Microsystems commissioned the Trace Center to create a JAVA accessibility report based upon the Center’s work. This report was then used by SUN as the foundation for initiating their accessibility work around JAVA.

New VoIP Accessibility Recommendations

The Trace Center, as part of the work on the Access Board’s TEITAC Advisory Committee, brokered a consensus agreement between consumers and industry on access to next generation telecommunication (VoIP) systems. The recommendations relieved industry from some current regulations around TTY support on IP systems in exchange for agreement to provide a text conversation option, wherever there were voice conversation options in IP communication systems. Further, any devices with multi-line displays would support the text conversation natively on the receive side and systems with keyboards would support it on the send side. In this fashion, individuals who are deaf could use mainstream products rather than having to buy special assistive technology when they need to communicate in text. Mainstream users would also be able to supplement any voice conversation with text as desired. This work has culminated in the commitment of AT&T to build real-time text into all of its VoIP infrastructure by 2017, and in the real-time text requirements coming out of standards for next generation 911, and the Access Board and the Federal Communication Commission (FCC) requirements for all VoIP telecom.

New Guidelines for Photosensitive Seizure Disorders

In the past, accessibility guidelines have forbidden any rapidly flashing content, even if it was so small or dim as to not provoke seizures. Working with Dr. Graham Harding and Cambridge Research Systems Ltd, the Trace Center developed a new measure for Web content and computer software that allows manufacturers to either use the older, simpler, but more restrictive rules, or new guidelines, which provide additional flexibility for some critical types of web content and computer software. These guidelines have been adopted by the World Wide Web Consortium in their new guidelines, which will have worldwide application. They have also been adopted by the US Access Board’s Advisory Committee and are used in the revised 508 regulations.

Quantitative Color Vision and Sensitive Contrast Guideline

Previous access guidelines simply required that “sufficient contrast” be used, making it impossible for developers to conform or know what was sufficient. Working with vision researchers and standards, the Trace Center developed quantitative measure for contrast based on research results and current standards. The standard is based on luminance, making it work for individuals with widely varying color vision deficits and visual abilities. These measures have been adopted by the World Wide Web Consortium for use in its guidelines. They’ve also been adopted by the Access Board in its revised 508 guidelines.