Shares of Applied Signal Technology ( APSG) were among the best-performing technology-related stocks Friday, surging 23% after the company's fourth-quarter results easily beat Wall Street estimates. For the quarter ended Oct. 31, the maker of digital-signal processing products earned $3.1 million, or 26 cents a share, up from $2.4 million, or 21 cents a share, a year ago. Revenue rose to $57.6 million from $39.5 million last year. Analysts polled by Thomson First Call expected earnings of 21 cents a share and revenue of $44.4 million. Following the earnings report, Applied Signal was upgraded by Caris & Co. and CE Unterberg. Shares were up $4.51 to $23.85. Shares of Hauppage Digital ( HAUP) slid after the company said it swung to a fourth-quarter loss on a 7% year-over-year decline in revenue. The maker of television parts lost $864,371, or 9 cents a share, in the quarter ended Sept. 30, compared with earnings of $119,261, or 1 cent a share, a year ago. Sales were $15.4 million in the latest quarter compared with $16.5 million a year ago. The company said its gross margin fell from 25.6% to 21.7% in the latest quarter, primarily reflecting higher sales of lower margin OEM products. Hauppage shares fell 84 cents, or 13%, to $5.56. Tech outsourcer Affiliated Computer ( ACS) rose on a report it is discussing a buyout with a group of private equity investors. Bain Capital, Texas Pacific and Blackstone reportedly are mulling a deal that would pay existing holders $62 a share, the New York Times said. The deal could still fall apart, the paper noted, citing people familiar with the matter. Word of the possible takeover comes about two months after Lockheed Martin ( LMT) and two private equity allies reportedly backed away from a deal for Computer Sciences ( CSC), another outsourcing giant. Affiliated Computer's shares were recently up $2.62, or 4.5%, to $60.70 a share.