Two of my favorite bartenders were Tim Costello and Jimmy Glennon. The two Irishmen owned and worked their places on Third Avenue in New York.

Like West Pointers at attention, these old bartenders had a stance of their own. During lulls, they would lean an arm on the bar, the other hand on the hip, cross one foot over the other and stare through a smudge-smeared window bearing their names in reversed lettering.

They were proud of the drinks they dispensed, and they were great sources of information.

You could find out who was working and who wasn't and where a job might be.

They knew all the latest gossip and only told you what they thought you could handle.

Problems were listened to on a slow night with a look of commiseration, but never a solution offered.

Now comes New Technology. The bartender we've come to know and depend on could be an endangered species. The computerized bar has arrived. It's here and there, around town. Just a few places, so far. I heard about it from a friend, a retired sportswriter. On a recent afternoon he found himself with time to kill, and so repaired to a certain saloon. He sat at the bar, ordered a dry Manhattan and, to his surprise, watched a young man go to a computer and punch out his drink.

"I never saw it before," he said. "This nice clean-cut kid pressing buttons and then he brings me my drink . . . I didn't know what kind of whiskey went into it."

It sounded ominous.

Bartenders have long been a part of history and have managed to survive even during 13 years of Prohibition. In fact, they thrived during Prohibition.

It was 1920 when every establishment in the United States selling alcoholic beverages was told to cork its bottles and turn off the taps. But by 1922, New York City police commissioner Grover Cleveland estimated the number of illegal drinking places to be about 32,000, more than doubling the legal spots before Prohibition. A politician closer to the taps placed the number at about 100,000. When FDR signed a proclamation ending Prohibition in 1933, there was wild celebrating in many cities, and in Baltimore one of the great drinkers, H.L. Mencken, stood at a bar and toasted the occasion by lifting a glass of water and saying, "My first in 13 years."

The barroom as we know it in America was a transplant from the tavern in England, a place to meet, sip ale and toss ideas around. There is no university in the world that could match the learning experience of an afternoon at the Falcon Tavern when Shakespeare, Ben Johnson and Kit Marlow (who was later killed in a tavern brawl at a young age) would sit and exchange wit before moving over to the Mermaid Tavern and again trying to outdo one another.

George Washington made his headquarters in Fraunces Tavern in lower Manhattan, the Marines were born in the Tun Tavern in Philadelphia, and it has been said that Thomas Jefferson spent long hours in the Indian Queen Tavern, also in Philadelphia, writing and rewriting the Declaration of Independence.

I doubt if any of this would have happened had there been push-button bars back then. Would the men of history have frequented a place without a certain ambiance, without the familiar innkeeper wiping the bar clean and greeting his customers with their favorite drinks?

As for Costello and Glennon, they would have closed the doors before allowing any kind of a dispenser in the place except for one that sold cigarettes.

They never heard of the "Happy Hour," or serving women drinks for a penny from 5 to 7 to attract business.

The customers were regular and that's all they wanted in their saloons.

Glennon never served food and skirted a N.Y.C. ordinance that stated establishments selling liquor had to sell food by having a huge bowl of hard-boiled eggs on the bar, a jar of pickled pigs' feet and another of kielbasa.

The drinks were mixed in front of the customers as part of the ritual of preparation; the eyes did the measuring, and how long the wrist was bent while pouring was the barometer.

These, of course, were the days before "I'll have a white wine" replaced greetings across the bar; if someone ordered wine they would have had to send out for it.

Drinks ran in a range of about five: martinis, Manhattans, straight whiskey, a shot and a beer chaser, or a tall glass of cold beer or ale from a fresh keg in the cool cellar and run through clean pipes.

There were a few fights, too, and if one happened it was over with quickly, because the bartenders of those days were stern, and the man causing the trouble was thrown out for the night, and maybe many nights to follow, depending on the extent of the crime.

Unruly patrons were unceremoniously shut off, and if they couldn't make it home, a cab was called--all courtesy the bartender.

Phones were always answered with a hand over the receiver and the guy getting the call was always asked if he was there.

They loaned money, though not a lot, ran tabs until they became high, cashed checks and knew the latest daily double or the early number pool.

Costello could keep every glass filled at his long bar, even when it was two deep.

Glennon loved to mix his martinis or Manhattans in a big metal container, stirring with a long spoon and pouring them out right to the brim of the glass every time.

I decided to invite a friend to join me in checking out the computerized bar. He had 20 years in the bar and restaurant business, but was surprised to hear of the spreading automation.

During the cab ride over he was agitated and said, "Men have invented the iron maiden, the rack, and someone created the Denver boot, maybe the guy who thought up the computer bar should win a place alongside these nameless shadows of history."

When we got to the place we found a flat keyboard of 96 buttons. One of the guys in charge said, "Ninety percent of the customers' reaction is psychological . . . But the complaints disappear after several drinks."

It turned out that the computer was developed and produced by the American Beverage Control Co. of Akron, Ohio.

"We have been in business since 1974 and have from 250 to 300 customers throughout the United States, mostly in motels, military bases and larger type bars," said Larry McKay, vice president of finance for the company.

"To install a pouring station in a bar, the cost would run roughly $25,000 for equipment, installation and tubing," McKay said. "The system can pay for itself very quickly. An owner can increase his sales volume by l0 percent without adding extra people or purchasing more liquor for his stock. There is no way for a bartender to give away free drinks to a pal, absolutely no spillage or overpouring. The computer can dispense 1,200 varieties of drink from 64 different brands of liquor."

Any smart businessman would install a computerized bar, I suppose, but what about that personalized service only an old-fashioned bartender can provide. Like Costello, who would listen to a steady customer's complaint about an ulcer giving him trouble and mix him a Scotch and milk for a little coating of the stomach on the way down. Would there ever be a computer programmed to serve Scotch and milk, with tenderness?