Open 11 a.m. to 9 p.m. daily. No credit cards. Personal checks accepted. Accessible to the handicapped. Parking in lot in front of restaurant.

We were debating what restaurant to go to for dinner one night when our son, 9, piped up with his preference: "Wherever I have to get dressed up the least."

O'Brien's Pit Barbecue definitely fit that order. The flat, squat restaurant doesn't look like much from the outside, or even from the inside, and any attire fancier than jeans would be out of place. For those who like to eat hickory-smoked barbecue, the setting and dress code are beside the point. Hearty, inexpensive meals, smelling of hickory and touched up with barbecue sauce are what attract customers to this remote setting on Gude Drive in Rockville.

This was our first taste of hickory barbecue, and we weren't sure what to expect. We had visions of a big open pit, lots of smoke and sizzling meat. Instead, the barbecuing pits, if pits there be, are hidden from view. The cooked meats are presented cafeteria style.

It didn't take us long to make up our minds about what to order. There were six dinner choices: branded beef, $3.75; sausage, $3.40; pork, $3.75; smoked ham, $3.40; ribs, $4.75; and chicken, $2.88. A mixed corral, for $4.25, was an adult combination plate; the yearling special, for $2.75, was for children under 12. Dinners came with a choice of two of three side dishes - baked beans, cole slaw or potato salod. In addition, those who ordered a dinner had unlimited access to the salad bar. Sandwiches, priced from $1.70 to $1.40 and made of ham, sausage, or sliced beef, were also available.

The beans, cole slaw, potato salad and a deep trough of barbecue sauce were within self-service reach. A young man behind the counter filled the meat orders.

We had to ask what branded beef was. It sounds like a steak with seared markings on top. It is not. It's a hickory smoked brisket, sliced to order.

Our son asked for ribs, and the young man behand the counter reached for a rack of them and quickly hacked them into individual ribs. My husband asked for the mixed corral and saw branded beef sliced to order, sausage and ribs heaped on his plate. I asked for chicken. It fell apart as the young man attempted to cleave half a chicken into three parts. He apologized, saying that three hours of slow cooking over the hickory fire makes the chicken very tender.

We helped ourselves to the cole slaw, potato salad, beans and extra sauce. At the end of the cafeteria line, we chose our beverages - milk, soft drinks or beer by the pitcher or mug.

We paid our tab and headed for the dining room. There were only three or four families there the night we went so we had our choice of tables.

There wasn't a tough piece of meat on any of our plates. Everything had been cooked perfectly - no grease and rich seasoning, very definitely hickory.

I had tried a light sprinkling of extra barbecue sauce for my chicken and had to return to the line to douse it with more. The chicken came off the least well among the meats we tasted. First place was a tie between the branded beef and the sausage.

The cole slaw was adequate, the potato salad and beans good. Our dinners also came with huge slabs of what O'Brien's calls toast. It's thick bread, fried on one side, hot but untoasted on the other side. It's just what we needed to mop up extra barbecue sauce.

Given the large portions of meat, the side dishes and toast, we never did make it to the salad bar.

The beer, was another highlight of dinner. Budweiser and Michelob are served on tap ($.55 to $.65 a mug; $2.50 to $2.60 a pitcher).My huyband's beer came in an ice-cold glass mug, filled with ice cold beer - so cold he swears there were tiny bits of ice on the top.

Desserts did not look appetizing - squares of cake in plastic wrap for 50 cents. Besides, we were too full to even consider it.

The tab for dinner was $12.45 for three of us (Our son was charged as a yearling). We were in and out of O'Brien's in 45 minutes; it took that long because we lingered over a second mug of beer.