The Nasdaq composite index fell a scant 0.24 to close at 3,205.11, and the Standard & Poor's 500 index dropped 3.50 to 1,378.02.
The Dow Jones industrial average fell 24.68 to 10,299.24, led by Alcoa.
For the week, the Nasdaq lost 5.9 percent, the fourth consecutive week it has lost ground. The S&P 500 slipped 2.1 percent, and the Dow lost 3 percent. The Nasdaq is off 21 percent so far this year, and the Dow is down 10 percent.
At the end of regular trading, Intel was up $2.38 at $117.56. Two weeks after recalling nearly 1 million computer motherboards because of a faulty component, Intel is telling computer makers that a revamped part should be ready next quarter.
Shares of Microsoft dipped 6 cents to $61.44. The government refiled its proposal to break Microsoft in two pieces, clearing the way for a final ruling in the antitrust case as early as next week.
The CNET tech index gained 4.19 to 2,452.31, led by shares of Adaptec. Losers and winners were balanced, with 47 of the 99 stocks in the index falling, 44 rising and eight remaining unchanged.
Of the 18 sectors tracked by the index, computer distributors posted the sharpest decline, falling 3 percent. Telecommunications equipment makers were the largest gainers, climbing a slim 1 percent.
Laser-vision company Summit Autonomous was the biggest percentage gainer on the Nasdaq Stock Market. The shares jumped $5.81, or 46 percent, to $18.50. Volume topped 13.8 million shares, more than 13 times the stock's daily average. Alcon Laboratories agreed to buy Summit for $894 million.
Among members of the CNET tech index, Adaptec rose $1.88, or 11 percent, to $18.50, and Lucent Technologies rose $3.50 to $56.
DoubleClick fell $4.44, or 10 percent, to $41.13. Ciena dropped $4.81 to $99.69.
The Philadelphia semiconductor index inched up 7.95 to 909.66, led by chip designer Rambus, which gained $9.25 to $163.
Baan fell 6 cents to $2.72 on a volume of 2.1 million shares, more than twice the stock's daily average.
As Baan's troubles have escalated over the past month, so has speculation that the company is a buyout target, with one more suitor's name added to the pool today.