Nevada residents became the first in the nation to vote on computers that leave a paper trail, taking part in a primary that produced scattered reports of delays — though none of the serious problems that have cast doubt upon electronic voting systems in other states.

A delegation of federal election officials monitored the equipment's debut Tuesday in the state capital as voters cast ballots for congressional candidates, state legislators, school officials and judges. Results matched expectations.

Scattered reports of problems — including in Nye, Washoe and Pershing counties — delayed vote tabulation, but didn't throw election results into question.

Officials in Nye County couldn't read the data on one computer but weren't overly worried. If they couldn't tease the results out of the machine — which held an unknown number of votes — they could count paper ballots by hand instead.

"If we can't ever read it, we'll use the paper trail as the backup," said Nye County deputy clerk Laura Zubia, who helped recover the data shortly after midnight. "That's the whole point of the paper trail, isn't it?"

Pershing and Washoe counties reported delays in vote totals because election officials were unfamiliar with the equipment. Poll workers' training was limited to one three-hour class.

Nevada's $9.3 million voting system — which includes more than 2,600 computers and printers deployed in every county — could become a model for other states. California, Washington and Illinois recently passed laws requiring a paper trail for electronic ballots, and at least 20 others are considering similar legislation.

Nevada Secretary of State Dean Heller said the system represented a "huge leap forward" for Nevada, where seven of 17 counties used old-fashioned punch card machines in the previous election.

"From what I've seen, voters seem to enjoy the experience," said DeForest B. Soaries Jr., chairman of the U.S. Election Assistance Commission, who traveled through Nevada on Tuesday with out-of-state voter registrars and other federal officials. "There hasn't been frustration or confusion."

The printers, developed by Oakland, Calif.-based Sequoia Voting Systems Inc., address some concerns of computer scientists and voting activists. Critics say paperless touchscreens — which as many as 50 million Americans will use Nov. 2 — cannot be properly audited or recounted, and votes can be altered or deleted.

Voter advocates praised Nevada's system, which requires county registrars to randomly select a small percentage of machines — from 1 percent to 3 percent of a county's total — and compare printed records with the vote totals taken from computers' memory cartridges after polls close. The paper records — which voters can see through a plastic window but cannot touch or take home — will be kept in county election offices for 22 months and used in case of a recount.

"It's no panacea, but it's a huge improvement over paperless systems because there will be a paper record of every electronic ballot," said Kim Alexander, president of Davis, Calif.-based California Voter Foundation.