ASIDE FROM selling 3 million volumes of poetry, directing a movie starring Bette Midler, creating a line of fabulously unsuccessful greeting cards, coauthoring a book on transcendental meditation that reached the top of The New York Times' trade paperback list, as well as the million-copies-in-print "How to Survive the Loss of a Love," Peter A McWilliams now enjoys the distinction of writing the two most popular books on personal computers, titled "The Word Processing Book" and "The Personal Computer Book."

The books have sold a combined 360,000 copies in a single year, and have been called "sprightly, clear, funny" (Newsweek), "just what the consumer needs" (The New York Times), and "pleasant and reassuring" ("All Things Considered")--all of this prompting the 33-year-old McWilliams to be dubbed "the Dr. Spock of computers" (The Houston Post).

High praise for a guy who says, "I really don't know that much about computers; I have no idea how to program them. The whole idea is to show people that they don't have to be afraid of computers, that they can in fact live up to the term 'user-friendly' that's bandied about so much now."

McWilliams seems quite friendly himself. He lists his phone number in the back of his books, and offers readers free updates of his recommendations on computers for the price of a self-addressed, stamped envelope. He laughs a lot--both at himself and at others--and smiles a big smile that is located beneath two green eyes and a fairly short crop of curly blond hair. As a joke, he distributes yellow pencils labeled "McWilliams II Word Processor." He wears no jewelry, not even a wristwatch, which prompts him to admit that the lack of gold chains around his neck has destined him to leave California soon--specifically in September, when he will move to an apartment in Greenwich Village. He does not smoke, take drugs, drink alcohol or eat liver and says, "What people see in papaya I'll never understand."

His audience, he notes in the introduction to "The Personal Computer Book," is "people who don't know the difference between a microprocessor and a micro-organism--who think a 'Pac-Man' is a member of the Sierra Club." His books, he says, are written for people watching TV commercials who "have asked themselves, 'Dick Cavett?' 'George Plimpton?' 'Charlie Chaplin?' " His explanations of the history and internal functioning of computers are equally offbeat. What makes the personal computer so powerful, he writes, is not so much its high level of intelligence; no, "a computer is very simple-minded. It knows only two things: Yes and No." But it can make these decisions with lightning speed: "One of these little yes/no circuits can say 'no' faster than Debby Boone."

This is not to imply that McWilliams sees the computer as the panacea of modern man and woman. He is the first to admit that some tasks--including balancing the checkbook, scheduling appointments, filing recipes and reading the newspaper--are better done manually. He knows. He's tried. And he's hardly an antirevisionist sort, save perhaps in one area: He puts no period after his middle initial because "whenever I see a period I pause. If I'd known what a commotion and how many typos the A for Alexander without a period was going to cause, I never would have used it, although I think it adds a bit of formality, as in Harry S Truman and David O Selznick."

Formality aside for a moment, that McWilliams came to write about computers is almost as inexplicable as his very vocation as a writer. He grew up in a lower-middle-class family in the Detroit suburb of Allen Park. His father, who died in 1971, was the supervisor of the cigar and candy department at Cunningham Drugs. "He never made more than $7,000 a year in his entire life," McWilliams says, "and nobody in our family ever read. There were a few books in the house, but they were enshrined, out of reach, behind glass doors.

"I discovered writing when I was in Allen Park High School. I'd fallen in love for the first time, and I asked my sociology teacher to let me write poems instead of term papers. He was a very liberal guy, sort of like Donald Sutherland in 'Animal House.' He came back the day after I handed in the first one, and said his girlfriend wanted a copy. Then his girlfriend's girlfriend wanted a copy. Well, this was at a time when photocopies cost 50 cents each, and it was getting expensive. Eventually I did a volume of them, 'Come Live With me and Be my Life,' on a mimeograph machine. I went through two 75-cent editions of that, and then had them printed, and charged $1.75. Now they cost $3.95. I went off to college at Eastern Michigan University, to study drama. For all of 1968 I went to work from 11 at night to 7 in the morning as a short-order cook at Biff's in Detroit. I can still flip eggs in a pan. Then I'd go to class from 8 to noon. I'd sell poetry books to stores until about 6 at night and then sleep until 10:30."

A sample McWilliams verse, from one of his 17 volumes respectively titled "Come Live with me and Be my Life," "Come to my Senses," "For Lovers and No Others," "The Hard Stuff: Love," "I Love Therefore I Am," "Love . . . An Experience of," "Love is Yes," "Evolving at the Speed of Love," "Love and all the other Verbs of Life," "Love Poems," "Catch me with Your Smile" "Nice to Know Someone Like You," "This Longing May Shorten my Life" and four others whose titles even McWilliams, who still writes these things, cannot recall: And through all the tears and the sadness and the pain comes the one thought that can make me internally smile again: I have loved.

"I can knock my poems as well as anybody else," McWilliams says. "Actually I was shocked that people would pay for them, but I became the paperback Rod McKuen. I used to tell people that I was the best-selling poet under the age of 30, until I discovered two years ago that Richard Thomas, who plays John-Boy Walton, was outselling me. So then I'd say, 'I'm the second best-selling poet under the age of 31.' It's something I can live with."

Within three years, McWilliams was making a fairly comfortable living as Detroit's most successful poet. At night, he would often drive over the Canadian border into Windsor, Ontario, to visit the Top Hat Supper Club, where he met a singer named Bette Midler. "She was very bored during the day," he says, "so I paid her $250 to star in a film I had written."

The movie, written, produced, directed and edited by McWilliams, was given the incredibly original title "The Greatest Story Ever Told." Midler was cast as the Virgin Mary. McWilliams moved to Los Angeles to finish editing the movie, and found a distributor, who retitled the work "The Divine Mr. J." The film is rarely seen, and its major accomplishment was to have consumed virtually all of the money that McWilliams had earned as a poet. "I used to think it was the worst movie ever made," he says, "and then I saw 'Eating Raoul.' "

But living in the land of dreams--actually, in an apartment once inhabited by Ginger Rogers--McWilliams managed to come in contact with an individual who convinced him that there was a unique financial opportunity available for someone who could write a book about transcendental meditation, a discipline McWilliams had first come in contact with in 1969. In 1975, in conjunction with Denise Denniston, he saw the publication of his first hardback work, characteristically titled "The TM Book."

"I wrote it to let people know about TM," McWilliams says. "TM promised cosmic consciousness in five to eight years. I did it twice a day for eight years. At five years I decided I was on the eight-year plan. At eight years I realized that I hadn't achieved cosmic consciousness and I stopped."

However successful his poems and "The TM Book" were, McWilliams was hardly prepared for the astounding impact of his next project, a little book called "How to Survive the Loss of a Love," written in collaboration with Melba Colgrove, a friend who had once been his psychologist, and a psychiatrist named Harold Bloomfield. The book began as a written response to a woman who had sent a letter to McWilliams about one of his volumes of poetry. "She was distraught, and I wasn't sure I knew what to write to her," he says. "So I wrote something called 'Thirteen Things to do When there's Nothing to be Done,' and later expanded it into a book of 58 things with two people who understood the psychological aspects of the problem. It's very thin, not many words on a page, not many pages in the book, but it's exactly what people need when they're depressed and can't read." The sections of the book have titles like "Recognize the Loss" and "Be Gentle with Yourself" and "There is Beauty in Sadness."

Merv Griffin called it "one of the loveliest books ever written." Others have said less lovely things. "There was one guy," says McWilliams, "who referred to it as my 'So Your Love Is Dead' book." Nonetheless, it has sold over a million copies, an achievement noted recently in a commencement address at American University given by the writer Ann Beattie, who observed that while 8,000 copies of "How to Survive the Loss of a Love" (which includes many of Peter A McWilliams' poems) are sold every month, perhaps 2,000 copies of the collected poems of William Butler Yeats are sold each year.

"Which just shows," says McWilliams, "that people lose loves more than they need Yeats. Besides, this Ann Beattie woman makes up stories; I tell people how to do things."

Through all his writing, the one thing that McWilliams never could stand was sitting down and hitting the keys. "I am incompetent at the typewriter," he says, "and I am the world's worst speller. Do you have any idea how it affects your style when you have to consult a dictionary three times for every sentence?"

In 1980, a friend familiar with McWilliams' love of gadgets mentioned to him that there now existed computers that not only could eliminate the need for retyping, but also were capable of checking for spelling errors. "This was beyond my wildest dream," says McWilliams. "I got to try a spell-checking program called 'The Word' that cost $75, and it was the answer to one of my most serious problems. I knew that I had to have it. There were two problems. One was that I had to have a computer, which was easier said than done in 1980. Do you realize that there were no computer stores three years ago? The other problem was that I had almost no money. I had blown most of the profit from the books on a very unsuccessful line of greeting cards.

"I spent eight years researching word processors. I had to pose as a dealer just to see them at the distributors. I even had to get a business license. Eventually I bought a Northstar Horizon, a Televideo 950 terminal, a NEC 5510 Spinwriter and 'WordStar' and 'WORD Plus' programs. The first thing I wrote was a review of 'The Word,' and I sent it around to all the computer magazines that existed in 1981. There were four: Byte, Compute, Killobaud Microprocessing and Personal Computing. Killobaud Microprocessing just printed it. I never heard from them. Personal Computing called me up and commissioned a 3,000-word article on word processing. They said, 'Assume the reader doesn't know what a personal computer is,' and by the time I was done explaining what a computer was, and what word processing was, I had 16,000 words. Then I realized what I had was a book. I had never written so many words so effortlessly and I wanted to let other writers know that computers were not something they needed to be worried about.

"One of the best things about word processing is that it makes publishing so easy. The first two editions of 'The Word Processing Book' were actually set on the Spinwriter, with the plates made right from the typewritten pages. It looked horrible, but the book was done and out there in a matter of two months. The first printing was 3,000 copies. Ingram, the book distributors, took 1,500 and gave me a check in 15 days so I could pay the printer. I spent $4,000 on a direct-mail campaign to the subscribers to Writer's Digest. That turned out to be a waste of money, and these were the people who should have been reading the book. Then I took out an ad in The New York Times Book Review, two columns next to the trade paperback list, for $4,000, and that sold 1,000 books by mail. With that $10,000 I printed another 3,000 and they sold. Then I bit the bullet and dumped all the copy over the telephone line to a typesetting house and had real type set and printed 10,000 copies.

"By now 'The Word Processing Book,' which came out in April of '82, is in its sixth edition, 12th printing, with 170,000 sold. 'The Personal Computer Book,' published in November of '82, is in its third edition, 11th printing, with 190,000 sold. These are the only two books in history to go through a new edition every two months, to try to keep them current. After I wrote 'The Word Processing Book,' I thought it just wasn't fair to take people this far and leave them hanging there. I wanted to warn people about specific things. So I added a buyer's guide at the end, but I recognized that it would be outdated when it came out. So I instituted the idea of updates. You send me an envelope and postage, and I'll let you know what's happened in the last couple of months."

Here's an example of McWilliams updating "The Personal Computer Book," reviewing a little $1,790 number called the Morrow Micro Decision:

"My only complaint, as a user, is the noise the disc drives make. Sometimes they sound like a subway breaking, and at other times they sound like Darth Vader breathing . . ."

McWilliams gets about 40 letters a day from his readers. "It taught me a lot, and consoled me that I could go on typing with two fingers and get somewhere in life," a professor wrote from Eugene, Ore. A writer in Santa Monica, Calif., said, "While reading 'The Word Processing Book' I laughed often to the great annoyance of those around me."

Some of these letters, with responses, will make up McWilliams' next book: "Questions and Answers on Word Processing." Also in the works is "The Personal Computer in Business Book," something McWilliams is aware of since he now employs 10 people and owns three computers. There is also The McWilliams Letter, a $100-a-year newsletter with 250 subscribers, and a weekly column on computers that is syndicated to newspapers.

Right now, McWilliams is very high on the Epson QX-10 computer system, the IBM personal computer and the Kaypro II. He is much less high on Atari and Apple computers, and most versions of the Radio Shack TRS-80, although he thinks the new model IV is pretty good. It is the Apple, however, that receives the brunt of McWilliams' criticism--including 11 anti-Apple cartoons in "The Personal Computer Book"--partly because he feels it hasn't made any significant technological advances since its introduction, and partly because McWilliams considers it overpriced.

"Steven Jobs, the chairman of Apple, just hired a very high-level executive away from Pepsi-Cola," McWilliams says. "The guy was making $500,000 a year, and Jobs gave him $2 million a year, a $1 million golden parachute and stock options. Imagine if Joan Crawford were still around, what she would have gotten!"

Although these numbers are still out of his league--"I'm nowhere near a millionaire yet," he says--McWilliams has been enjoying life a little more now as the middle-class maven of the microprocessor. Recently he came to New York to have a musical portrait written by Virgil Thomson, the 86-year-old critic and composer who was a good friend of Gertrude Stein, one of McWilliams' favorite characters.

"I had read his books and wrote to him and he invited me to visit him at the Chelsea Hotel where he lives," McWilliams says. "I asked him a lot of questions: How was Stein's apartment laid out, what was it like taking peyote, what did one do back then if one got VD, how does one get a musical portrait written? And he said, 'You pay $1,000 and you come and sit.' "

And so McWilliams, bearing gifts, comes and sits. The gadget nut brings a microphone and an amplifier and a set of headphones, in the hope that this will help mitigate Thomson's hearing problem. He sits at Thomson's feet and talks into the microphone. Thomson says, "Put it on mono. Stereo's just a word. It doesn't mean a goddam thing." Then Thomson says, "Put away the toys. I want to get on with the portrait." McWilliams sits in a chair. He reads a book. He falls asleep. For an hour and a half Thomson makes notes on music paper. Afterward, McWilliams says, "I have no idea what this thing sounds like; I have to find somebody who can play the piano."

A few days later, McWilliams flies down to Miami to see Christo's "Surrounded Islands." He actually gets to meet Jeanne-Claude Christo, the artist's wife, who tells him that she and her husband have been using a computer for years and it is nothing but a headache. They talk about some programs, and various pieces of hardware, and when he is about to leave, McWilliams says he is going to send them a copy of his newest book.

"Is it about computers?" asks Jeanne-Claude. "Then please, don't send it."

And without a pause, Peter A McWilliams leaves the Surrounded Islands behind. In another week they will be gone, and he will be sitting at the keyboard of his Horizon, getting new editions of his books ready for the typesetter.