For over a decade, the Town Theatre at 13th Street and New York Avenue NW has been synonymous with low-budget kung fu movies, a place where street bums enterprising enough to scrape up $1.50 could spend an entire day on stained but comfortable seats, munching left-over popcorn as actor Bruce Lee encountered The Deadly Dragons.

Today, the marquee no longer advertises double billings such as "Fists of Fury" and "Blacula." Coming soon, as the sign says, is "Airplane II." Now showing is "The Toy," a soft-shoe PG feature with comedians Jackie Gleason and Richard Pryor. But with the prices suddenly up to $4.50, one regular patron recently backed away from the ticket window and left, grumbling to his buddy, "Ain't nothing that funny, man."

Even the name of the 600-seat theater has changed, reflecting the new economic realities of downtown Washington. Located just two blocks away from the city's spanking-new convention center, which was dedicated in a ribbon-cutting ceremony last week, the Town Theatre was recently sold to Washington's premier movie theater owners, Paul Kirschner and Marvin and Ronald Goldman, of Kogod and Burka Theatres.

The new name: K-B Town.

What is happening at the new K-B Town is what city planners hope will happen throughout the down-at-the-heels neighborhoods around the convention center: improvement, renovation, a general sprucing up to make the area more attractive to conventioneers. But turning "downtown" into "uptown" is not always an easy transition to make.

"We're just trying to become a main-line theater," said Carl Marbury, the 21-year-old manager who started as an usher with the K-B Cerberus in Georgetown. "With the convention center just down the street, we expect this to be a very prominent theater in the city. After all, we're the only 'legit' theater downtown."

As the lights came on during a recent intermission, a squadron of ushers, some dressed in black suits and bow ties, moved through the theater with plastic garbage bags and flashlights.

"Organize it," Marbury commanded. "Work in teams. Top to bottom. Meet in the middle. We're not trying for immaculate, just clean. You know how people are. They don't want to step on a half-empty soda and mess up their good shoes."

A group of men who appeared to be nodding out on the back row with their feet propped up on the seats in front of them slowly began to stir, then finally shuffled down the aisle, adjusting knit hats and buttoning pea coats as they staggered into the lobby.

"It used to be a time when a man could have himself a movie and still have some money left over for refreshments," one of the men complained. A companion chimed in, "Nowadays, they charge you more for less."

On several occasions, police officers have been called in to remove patrons who had become accustomed to idling away the day inside the theater.

The old days are gone, says Ron Goldman, grandson of Fred Kogod and nephew of Fred Burka--the two Russian immigrants who started the 31-movie theater chain in the late 1920s. Goldman promises that the theater will be run just like the chain's theaters in more affluent neighborhoods such as upper Wisconsin Avenue.

The D.C. Pleasure Place, an adult bookstore that has 32 movie booths at 25 cents a reel, is located next door. The manager, who declined to give his name, says he has noticed that the marquee lights at the Town Theatre work now and that ushers regularly sweep the walkway in front of the building.

"It don't bother me," he said. A neighborhood's transition sometimes takes a while.