Jack Tramiel, a hard-driving businessman whose Commodore computers helped establish a mass consumer market for personal computers in the 1970s and 1980s, died April 8 at a hospital in Stanford, Calif. He was 84.

His son Leonard Tramiel verified his father’s death but did not disclose the cause.

Mr. Tramiel, a concentration-camp survivor and tough-talking former typewriter repairman, was an unlikely success story in the high-gloss world of Silicon Valley. Neither an engineer nor a designer, the chubby, cigar-smoking Mr. Tramiel (pronounced tra-MELL) was once considered a computer-industry visionary of the same order as Steve Jobs and Bill Gates.

As much as anyone, Mr. Tramiel transformed the computer market by figuring out how to build dependable home computers at a price that ordinary people could afford.

In 1977, he introduced the Commodore PET, the first personal computer to cost less than $1,000. Two other popular computers from competing companies, the Apple II and Radio Shack TRS-80, came on the market the same year.

Jack Tramiel, in a 1984 photo after buying the computer-games company Atari, died April 8 in Stanford, Calif., at age 84. (SAL VEDER/ASSOCIATED PRESS)

In 1980, Mr. Tramiel’s company brought out the Commodore VIC-20, but he made his most lasting mark two years later, with the Commodore 64. Designed by Mr. Tramiel’s chief engineer, Chuck Peddle, the Commodore 64 was a reliable, easy-to-use computer with a then-unheard-of 64 kilobytes of internal memory. It was one of the first PCs on which games could be played.

As the price dipped below $300, millions of Commodore 64s were sold worldwide, making it one of the most popular — and influential — personal computers in history.

“Commodore was a huge factor in the early days of personal computing,” Paul E. Ceruzzi, a historian of technology at the Smithsonian National Air and Space Museum, wrote in an e-mail. “The big impact of the Commodore 64 was its ability to play games. It had a fanatical customer base, who were also the creative driving force of Silicon Valley.”

By 1984, two years after the Commodore 64 was launched, Mr. Tramiel’s company had sales of $1 billion a year and commanded 42 percent of the U.S. home-computer market.

At the height of his success, the notoriously abrasive Mr. Tramiel had a dispute with other executives and shareholders of Commodore and abruptly quit the company he had founded almost 30 years earlier.

A few months later, he bought Atari, the struggling computer-games company founded by Nolan Bushnell, with hopes of turning it into a home-computer challenger to Commodore, Apple and IBM.

Within a month, Mr. Tramiel laid off almost 90 percent of Atari’s workers and hired a new management team, including all three of his sons. “I’m going to change this company from a democracy into a dictatorship,” he told the Toronto Star at the time.

After a short-lived turnaround, Atari’s fortunes began to falter, and Mr. Tramiel retired in 1996.

Nonetheless, the memory of his contributions, especially with the Commodore 64, remains strong among computer aficionados.

“During the wild-and-woolly early days of the PC,” Time magazine technology correspondent Harry McCracken wrote, “Jack Tramiel helped to define what a PC was.”

Jack Tramiel was born Dec. 13, 1927, in Lodz, Poland. His name at birth has sometimes been given as “Jacek Trzmiel,” but Leonard Tramiel said, “I’m not sure what his first name was. His Jewish name was Yehuda.”

Mr. Tramiel, an only child, went to work in a factory before his 12th birthday, soon after German Nazi authorities took control of Poland at the beginning of World War II.

During the war, he and family were shipped to the Auschwitz concentration camp. He and his father were later transported to a slave labor camp in Germany, where his father died. Mr. Tramiel was liberated by U.S. soldiers in 1945 and reunited with his mother after the war.

He came to the United States in 1947 and served in the Army. He drove a taxi in New York and, in 1953, used a G.I. loan to buy a typewriter repair shop in the Bronx.

He soon progressed from working on office equipment to manufacturing it. In 1955, he moved to Toronto, where he founded Commodore International, which was originally a company that built and imported typewriters and adding machines.

He settled in Northern California in 1968 and entered the electronics business by manufacturing calculators and digital watches. He nearly went bankrupt in 1975, when his primary supplier of microchips, Texas Instruments, began to build its own calculators at a lower price.

In 1976, Mr. Tramiel bought a Pennsylvania microchip company that had developed a landmark microprocessor, the 6502, that powered the early Commodore and other PCs. By controlling every step of the manufacturing, Mr. Tramiel was able to drive down the price of his computers, making the personal computer a product that ordinary people could afford — and ultimately could not live without.

Mr. Tramiel’s survivors include his wife of 64 years, Helen Goldgrub Tramiel of Monte Sereno, Calif.; three sons, Sam Tramiel and Leonard Tramiel, both of Palo Alto, Calif., and Garry Tramiel of Menlo Park, Calif.; and five grandchildren.

Mr. Tramiel was a major donor to the U.S. Holocaust Memorial Museum in Washington. Years after he was freed from the Ahlem labor camp, he was reunited with one of the soldiers who rescued him.

He also spoke of his Holocaust experiences to many school groups.

“I asked him why he didn’t do it more often,” his son Leonard recalled Tuesday. “He said, ‘Because when I do it, I shake for a week afterwards.’ ”