Los Angeles — In the 19th-floor, Century City offices of Embassy Pictures Edward James Olmos leans over a typewriter, pecking away, as well-dressed young staff members bustle up and down the halls.
He is the star in what he hopes soon will be a major Embassy release.
If ''The Ballad of Gregorio Cortez'' succeeds at the box office, he says, ''it will change the course of history in our country.''
That's why he has spent well over a year hustling to get the film released in major movie theaters around the country.
Mr. Olmos is a true believer in the power of the big screen and a true believer in what this film -- originally aired on PBS in the spring of 1982 -- can do for Latinos in this country.
Above all, he hopes it can break ground for more Hispanic heroes on the American screen.
Projects like ''Gregorio Cortez'' are in the foreground of a churning, still largely unformed Mexican-American culture. In the background are writers and playwrights working to make sense of the Mexican-American experience and create a new literary genre.
As this culture takes shape, and helps to form the Mexican-American conscience, what will be its language? Will it be the Spanish tongue of the Mexican's Latin inheritance or the English of America's Anglo-Saxon ideals?
Here, ''Gregorio Cortez'' reflects the language mix in the literature.
The hero of the movie is a turn-of-the-century ethnic Mexican living in Texas. Olmos speaks only Spanish in the role. No subtitles. Yet there is nothing about him or what he says that is hard for an English-speaking audience to understand.
The most common attitude among Mexican-American writers is that English is their primary language, while Spanish is used to lend authenticity to characters and scenes, especially in dialogue.
About 60 percent of Mexican-American literature has been in English, says Gary Keller, editor of the Bilingual Review/Press. The rest is in Spanish or in both languages.
''I used to worry about that,'' says Luis Valdez, who writes mostly in English. ''I don't worry about it any more.'' There is such a rich and complicated combination of languages in the Hispanic past -- from Indian tongues to the Arabic of the Moors -- that he quit worrying about which language he was using, he explains. ''I just had to admit to myself that I felt quite comfortable in English.''
Mr. Valdez, the hearty artistic director of El Teatro Campesino (The Farmworker Theater) since 1965, has written the most popular Mexican-American work to date -- the 1978 play and 1981 movie ''Zoot Suit.''
Eddie Olmos played El Pachuco in ''Zoot Suit'' on both stage and screen, speaking Calo, a sophisticated slang blend of English and Spanish.
Valdez tries to write for what he calls the ''new American'' audience -- English-speaking, European-based, middle-class America, together with the growing Hispanic- and Asian-Americans -- ''acknowledging, of course, that English is the lingua franca of the US and a large part of the world.''
These new Americans, he hopes, will come to be newly cosmopolitan and sophisticated, handling cultural differences with a new sense of ease.
Virtually all Mexican-American writers are writing about life at the philosophical and literal meeting ground of two major cultures: the Latin, Roman Catholic culture of southern Europe and Latin America; and the Anglo-Saxon, Protestant culture of northern Europe and North America.
''We're working in the crux of those two cultures,'' Valdez says.
''What Latin American art has to offer American art has yet to be defined. But it's there. It has to do with dreams, the wild imagination. I see American art straining toward that,'' he says.
Mexican-American poets have been especially free about combining the cultures line by line, switching from one language to the other from word to phrase. The bilingual poet Alurista is one of the most noted. Valdez, for one, finds Alurista's use of two languages beautifully done, ''But it's sort of a mule in a way, a cultural mule.''
In other words, heavily bilingual work has limited its audience too much -- to those literate in both languages -- to father a prospering bilingual literature.
Short-story writer Genaro Gonzalez, an American now teaching psychology at the University of the Americas in Mexico, says he originally wrote his stories in English, but kept the dialogue in the authentic Calo of the characters.
But he had trouble reaching a wide audience, even with publishing houses that catered to Hispanic readers, he says. After reading some excellent English translations of Latin American authors, he decided he could write English dialogue without weakening his stories' impact.
Becoming more relaxed and sure as a writer was part of it. ''There seems to be a stage many of us go through where we are posturing more and tend to write more in Spanish.''
Still, Dr. Gonzalez notes that some words have more powerful associations for him in Spanish, his first language at home, and don't translate well, such as ''madre'' vs. ''mother.''
Overall, most Mexican-Americans -- readers and writers -- are more literate in English than Spanish. ''There is more language loss among Chicanos than many like to admit,'' notes editor Keller.
It is in English that Mexican-Americans are beginning to penetrate the American culture. Keller notes a growing number of requests from publishers to reprint stories by Mexican-Americans in school textbooks. ''It's almost impossible for kids to get through school now without reading at least one Chicano writer.''
Some of the stars on the Mexican-American literary horizon:
* Nash Candelaria, a northern Californian who writes historical novels about the old Southwest, most recently, ''Not by the Sword.''
* Rudolfo Anaya, a novelist in New Mexico, author of ''Bless Me, Ultima.''
* Ron Arias, a southern California novelist who wrote ''The Road to Tamazunchale.''
* Alberto Alvaro Rios, an Arizona poet who recently won the Walt Whitman Prize for his collection ''Whispering to Fool the Winds.''
* Alejandro Morales, a southern California novelist who writes in Spanish, most recently, ''Reto en el Paraiso.''
Meanwhile, Luis Valdez is working on a Columbia Pictures screenplay for actress Jane Fonda based on a book by Mexican novelist Carlos Fuentes, and Eddie Olmos has his young son and a cousin helping set up screenings for ''The Ballad of Gregorio Cortez.''