`Masterpiece Theatre's' masterly new `Mr. Chips'. CBS's bizarre miniseries - `At Mother's Request'

Goodbye Mr. Chips PBS, Sunday and Jan. 11 and 18, 9-10 p.m. Stars: Roy Marsden, Anne Kristen, and Jill Meager. Writer: Alexander Baron, based on the novel by James Hilton. Director: Bary Letts. Host: Alistair Cooke. A BBC/MGM co-production presented by WGBH, Boston. At Mother's Request CBS, Sunday and Tuesday, 9-11 p.m. Stars: Stefanie Powers, E.G. Marshall, Doug McKeon, and Frances Sternhagen. Writer: Richard DeLong Adams, based on the book by Jonathan Coleman. Director: Michael Tuchner. Two miniseries premi`ere at the same time on Sunday - but scheduling is the only thing they have in common. ``Goodbye Mr. Chips'' and ``At Mother's Request'' fall at absolutely opposite ends of the emotional and philosophical spectrum.

``Mr. Chips'' is a sweet, sentimental, loving portrait of a schoolmaster coping with life during the years just prior to World War I, perhaps the last days of innocence in 20th-century society. ``Mother'' is an unremittingly grim tale of evil, madness, and weakness in a sordid and materialistic segment of society, which has made money its major goal. `Goodbye Mr. Chips'

In 1933 James Hilton, author of ``Lost Horizon,'' wrote ``Goodbye Mr. Chips,'' which deals with the life of a schoolmaster in Brookfield, a not quite top-level English public school (the American equivalent is ``private school'').

He based Mr. Chips on his own schoolmaster father. It became an instant success in England, then in America. In 1939 it was made into a lovely movie with Robert Donat and Greer Garson, and 30 years later into a best-forgotten musical film starring Peter O'Toole.

Now ``Chips'' is finally making its appearance in a new, expanded BBC version on ``Masterpiece Theatre,'' which excels in handling such delicate and precious subject matter.

From the moment Roy Marsden (detective Dalgliesh in ``Mystery!'') appears on screen to read from his diary as he looks back over his 63-year career at Brookfield, his projection of real human warmth, lovable ingenuousness, and consistent attention to standards is perfect. Marsden as Chips makes one believe in a world in which uncompromising quality is appreciated and even rewarded, eventually.

Sticklers for accuracy may insist that ``Goodbye Mr. Chips'' is as much fantasy as reality - that the old English public-school system encompassed many negative aspects not touched upon in this three-part miniseries. They may point out that rooms and water supply were often unheated, discipline sadistic, homosexuality rampant, teaching methods outmoded.

But ``Chips'' will have none of that. Just about everybody except the calculating and snobbish young headmaster turns out to be endearing and charming and understanding. The grounds are green and gorgeous. Only World War I breaks into the idyllic life at the school.

``Goodbye Mr. Chips'' makes for three hours of ecstatic nostalgia for a time, a place, and a way of life that few of us - perhaps not any of us - has ever had the good fortune to experience. `At Mother's Request'

If the story on which ``At Mother's Request'' was based were not true, it would be dismissed as badly plotted, improbable, irrational, and unbelievable.

It is all of the above. But it is true. The two people upon whom the principal characters are based - Frances and Marc Schreuder - have been convicted of the crimes they are portrayed as committing.

Two books were written about the case. In addition to this CBS miniseries, NBC is preparing its own six-hour version of the affair, which will air in a few months.

The big question is why.

Anyone who decides to watch this version should be prepared for bizarre relationships and psychological torture: A disturbed mother convinces her disturbed son that he can win her love by murdering her father so she can inherit a fortune.

As skillfully played by Stefanie Powers, the mother is cold, calculating, utterly repressed - ready to explode into full-fledged madness at any moment. The son, as played with chilling believability by Doug McKeon, is slovenly, weak, and by turns pitiful and scheming.

A major weakness of the miniseries is the lack of any attempt to delve into the early life of most of the people involved in order to show how they came to their unbelievable attitudes and actions. Writer Richard DeLong Adams too often uses simplistic voice-overs that turn out to be inadequate to explain what people are thinking or why.

``At Mother's Request'' does have a New York City panache and a Salt Lake City authenticity. But one yearns, if not for a hero, at least one partially admirable main character.

After the first hour, you may be annoyed at yourself for tuning in, though you may find it compelling to watch this whole group of unlikable people follow through on their whole series of incredible actions.

And you may conclude that this is an extreme case of what could happen to people without any real moral base.

``At Mother's Request'' offers no respite from evil. If that's not for you, better stick with the consummate ``Goodbye Mr. Chips'' on PBS.

Arthur Unger is the Monitor's television critic.