CHICAGO (AP) _ Ike is still president and Elvis remains king at a '50s-style diner where ponytails, poodle skirts, burgers and malteds are still the coolest.

There's a silver-plated counter area, miniature tableside jukeboxes that blare golden oldies, and the waitresses, with names like Bubbles and Suzy Q, serve up rib-sticking grub like meat loaf, chili and homemade hamburgers.

Ed Debevic's Short Orders-Deluxe, which opened two months ago, is part of a nationwide trend toward upscale versions of the greasy-spoon restaurant. Even so, most of Debevic's customers think the place is definitely one of a kind.

''I can't really compare it with anything. The closest you could say would be an amusement park,'' said Debevic's regular John Madsen, 22, a Chicago sales consultant.

The waitresses and waiters at Debevic's are required to assume '50s aliases and ''have to lean on the table, be witty with the customers, learn some diner lingo, learn to smack their gum and do the Debevic walk,'' said Steve Ottmann, project coordinator for the restaurant.

That walk is a, ''how would you say, sashay,'' said ''Blondie,'' alias Barb Supple, 23, who's worked at Debevic's since it opened Nov. 14 and has been a waitress since age 16.

''It's about the only restaurant that actually wants you to chew gum,'' said Miss Supple, sporting a roller-skate pin and a button picturing that all- American '50's boy, Beaver Cleaver.

Debevic's, including Ed himself, is the brainchild of Chicago restaurateur Richard Melman, who runs several area restaurants as president of Lettuce Entertain You Enterprises.

''Ed Debevic is made up,'' and is supposed to sound ''like the name of a guy back in the kitchen slinging potatoes,'' Miss Supple said. ''But when people ask, 'Where's Ed?' I usually say 'He's out bowling or playing bingo at the VFW.'''

Melman and business associate Lee Cohen of Phoenix, Ariz., wanted to create a ''back-to-basics'' restaurant with simple American food, Ottmann said. They toured the back roads of America to get ideas for the decor and the eats.

The result was Debevic's, complete with aqua overstuffed vinyl booths, posters for Kayo's ''tops in taste'' chocolate drink, cherry Cokes and pinball bowling games.

About the only contemporary things at Debevic's are the prices: A hamburger goes for $3.35, while a malted milk with whipped cream costs $2.35.

''It's not a serious place, it's a fun place,'' Ottmann said. ''We encourage things that other restaurants don't. If you want to pull up a chair in the aisle, you can. If you want to sit six to a booth, do it. It's like anything goes.''

According to Ottmann, the nostalgic, let-loose atmosphere at Debevic's has drawn patrons of every age and social strata. ''You'll see limos pull up front, and we also have punk rocker-types and working people,'' he said.

For some, a visit to Debevic's is like a trip down memory lane.

''One guy said, 'Hey, I think I worked here in high school,''' said Miss Supple.

Debevic's is ''dynamite,'' said Carlos Hernandez, 29, a businessman who says he likes almost everything about the place. ''I grew up with the music. I love the music of the '50s. The people who serve you are all nuts - and I love it.''