Houston ? Voting in the nation’s third-largest county is going high tech. Instead of punch cards, voters here will use one-inch-thick, 5.2-pound electronic machines.

Harris County, Tex., will be the largest county to completely switch to an electronic voting system, county officials say.

Los Angeles County, the nation’s largest, has used touch-screen technology for pre-election day voting, while Cook County, which includes Chicago, still uses punch cards.

Voting booths in Harris County will have a device about the size of a legal pad, with a color screen. A gray dial at one corner will let voters maneuver through the ballot in English or Spanish, and beginning next year in Vietnamese, too.

Choosing a candidate will involve simply highlighting a name with the dial and pushing “enter.” The machine then reviews selections and permits corrections.

Voters in Harris County, Tex., are going high tech. Instead of perforating punch cards, voters will use electronic machines when they go to the polls Nov. 5.

Around the country, more counties are switching to electronic systems.

But that hasn’t ended vote-tallying difficulties. During Florida’s primaries last month, many touch-screen machines malfunctioned and poll workers were insufficiently trained.

Harris County Clerk Beverly Kaufman believes the county should be able to avoid those problems, having conducted test runs since last year during early voting.