Premier/Diebold (Dominion) AccuVote OS

The AccuVote-OS is a precinct and central accumulation optical scan voting system. The AccuVote is a small system, and can be transported without excessive difficulty. When using the AccuVote-OS as a precinct based optical scan unit, ballots are processed in the polling place, not transported to a central location. Only the voter touches the ballot between the time it is cast and the time it is counted. The AccuVote-OS integrates the vote tabulation and recording process into one unit. The unit is powered with both an internal battery source and an external source. The AccuVote-OS is currently in use in 900 jurisdictions.

Note: The AccuVote OS was marketed, first by Unisys and then by Global Elections Systems as the ES 2000 and is still referred to by that name in some jurisdictions. When Diebold acquired Global in 2002, the name was changed to AccVote OS. (See Background below)

Premier Election Solutions, formerly Diebold Election Systems, was purchased in 2009 by Election Systems and Software (ES&S) and was subsequently sold to Dominon Voting following a 2010 antitrust settlement.

AccuVote OS Voting Instructions

1. After you check in at the polling place, a poll worker will give you a paper ballot, which you will mark with the pen provided. Be sure to verify with the poll worker that you are using the correct pen for the machine used in your polling place.

2. Mark your choice on the ballot by darkening the oval (above right) next to your candidate’s name or selection. Follow the directions carefully to be sure your mark will count.

3. To cast a write-in vote, there are two steps: first, darken the oval for the Write-In position in that contest. Second, write the name of the person you are voting for on the line next to the Write-In oval. You must complete both steps to be sure your write-in vote will be counted!

4. When you have made all the choices you wish to make, review your ballot carefully. If you have made a mistake marking your ballot, ask a poll worker for another ballot.

5. When done voting, take the ballot to the scanning machine and insert it face up. If you have voted for more candidates for a race than can be elected (“over voted”), the machine may reject your ballot and will offer you the opportunity to correct your mistake. You may choose to submit your ballot as is, or correct the over-vote by marking a new ballot. (If you submit as is, your votes will be counted for all races except the over-voted race.) If the scanner is not working, your ballot will be secured to be scanned later.

A Voting Demo from the CT Secretary of State:

A Pollworker Training Video from Fairfax County VA:

Security Concerns

Security Seals Ideally, the OS’s exposed ports, memory card access areas, ballot box doors and case seams would be covered with tamper-evident security seals. The integrity of these seals should be maintained at all times, and only breached under controlled, explained circumstances. Seals should be logged to maintain chain of custody of sensitive materials.

Keys The keys for the AccuVote-OS are the same for all AccuVote-OS machines and are easily pickable with readily available tools. Care should be observed around the ballot box lock and the scanner key lock (turns the system off and on).

Ballot Box Access Optical scan systems have at least one and possible more ballot boxes. Each ballot box should be inspected by a voter at the beginning of voting to make sure that they are empty. These ballot boxes should locked and/or be sealed with tamper-evident tape.

Memory Card is Sensitive Corrupt memory cards may be able introduce viruses, cause the main election server to crash and falsify votes. Access to the memory card should be controlled, monitored and logged at all times.

Correct Inks Some Optical Scan systems have trouble reading red inks or inks with red in them. Voters should use the writing instrument provided at the polling place or, if voting at home, black ballpoint pen that does not bleed through paper.


In 1989, a precinct-count voting system emerged in the marketplace, the Unisys ES-2000. This was built under license from Data Information Management Systems of Ventura, California. DIMS held a patent granted to Kenneth D. Webb for a precinct-count voting system similar to the MTB-2 in that it used a long narrow single-column ballot. The ES-2000 was a vast improvement on Webb’s system in that it used standard-sized paper with a very flexible layout of rows and columns. Unisys Corporation was the result of the merger of two old computer giants, Burroughs and Sperry-Univac. The Unisys press release announcing the ES-2000 emphasized that voters could insert their ballots directly into the scanner and that, at the end of the day, the scanner would automatically upload the results into a Unix-based server at election headquarters.

By the Spring of 1990, Anoka County Minnesota had permission to use the ES-2000 in their primary and general elections that year. Unisys was now selling the ES-2000 under the trade-name Accu-Vote.

The ES-2000 was actually developed by another company, North American Professional Technologies. NAPT was founded by Clinton H. Rickards in 1983, and began development of the ES-2000 in 1986. Development of a new voting system is expensive, and by the time the ES-2000 came to market, NAPT was a subsidiary of Macrotrends International Ventures Inc. of Vancouver. Macrotrends was a venture capital firm with a sometimes questionable reputation. How did Unisys get involved? The answer is simple: marketing and service. Unisys computer systems were still widely used by governments at all levels in the 1980s, so the Unisys sales and service organization had good connections with people who might be willing to try a new computerized voting system.

The relationship with Unisys did not last. In late 1991, NAPT merged with Macrotrends to form Global Election Systems Inc. The corporation was technically Canadian, but the executive offices were in McKinney, Texas. Global immediately purchased a share in the patent rights of Data Information Management Systems. Through the decade of the 1990s, Global would grow to become a major force in the election equipment marketplace, largely on the strength of the AccuVote ES-2000.

In 2002, Diebold Inc., a well established manufacturer of bank vaults, automatic teller machines and other security-related products, bought Global to create Diebold Election Systems Inc. Global and Diebold continued to make the AccuVote ES-2000, although the name changed to the Accuvote OS, standing for Optical Scan, to distinguish it from the AccuVote TS, the touch-screen voting system that Global acquired with the purchase of I-Mark Systems.

  1. Douglas W. Jones and Barbara Simons, Broken Ballots, 2012