The Securities and Exchange Commission yesterday accused Tandem Computers Inc. and three of its officers of fraud for materially overstating its sales and profits in 1982.

The Cupertino, Calif., manufacturer of multiple processor computer systems, its president and founder James G. Treybig, chief operating officer Robert C. Marshall and Vice President Henry V. Morgan allegedly counted as revenue contingent orders and equipment shipments although there was no record of signed customer purchase orders, the SEC said. Also, shipments that occurred after the end of the fiscal year were counted in 1982 figures, the agency said.

The company and the principals have consented to the order without admitting or denying guilt.

According to the complaint, Tandem had 20 consecutive quarters of growth through the second quarter of fiscal 1982. In the third quarter, its revenue declined. In the fourth quarter, management told its sales staff that it was imperative that profitability be increased.

On Nov. 1, 1982, Tandem issued a press release announcing revenue for the quarter ended Sept. 30 of $91 million, up 41 percent from the same period in 1981, and that revenue for the fiscal year was up 61 percent. The SEC alleges that in that release, Tandem overstated revenue for the fourth quarter by $13.5 million. Furthermore, it said that second-quarter revenue was overstated by $6.8 million, and the third quarter's by $5.4 million.

On Oct. 29, Arthur Andersen & Co., Tandem's auditor, had recommended that the company adjust its fourth-quarter revenue downward by $18 million because it had recognized contingent orders as sales. It also found that the company lacked a centralized documentation of customer sales and had an improper shipping cutoff date.

On Dec. 8, 1982, Tandem publicly announced a restatement of its fiscal year 1982 revenue to $312 million from $336 million. After the announcement, the stock fell $5.75, the most actively traded stock over the counter on that and the next day.

The SEC also accused Tandem of failing to devise and maintain an adequate system of internal accounting controls. In the settlement, Tandem's officials agreed to an annual review for the next three years by independent accountants to assure the adequacy of its internal controls for accurately counting sales.