With a final push from news from the Gulf that the US had bombed an Iranian oil platform, the London market outdid Wall Street’s Friday tumble in spades yesterday, and by 2pm the FT30 index was off 207 points at 1605.90 – but Wall Street was in no mood to play second fiddle and itself plunged another 201 points mid-morning on top of its Friday fall of 108.35 points to 2246.74, before recovering to stand 118 off at lunchtime, New York time. In London the carnage was across the board, and the FT30 index closed down 207.1 at 1,605.8 while the FTSE 100 shed 273.1 points to close at 2,028.8. In the computer sector, Ferranti showed one of the biggest falls, off 24 pence to 109; Racal dipped 35p to 295 pence, GEC fell 36 pence to 196 pence and Plessey was off 22p at 194p. Despite its good news on the Hong Kong reorganisation, Cable & Wireless slumped 60 pence to 437p. STC was off 37p at 307p and Thorn EMI was off 56 pence at 659p. Atlantic Computers fell 31 to 638, and in the systems house sector, Logica shed 39p to 338p, Systems Designers 12p to 73p. Amstrad lost 28p to 141p and Apricot shed 28p to 109p. Maintainer DDT Plc was one of the few shares to be unmoved – but it’s anyway at an all-time low.The New York market was still open when we closed for press, but was clearly headed for its fourth consecutive decline; the previous record point drop was last Wednesday’s 95.46 point fall. For the week, the Dow index fell a total of 235 points, or 9.5%. Since the average’s peak on August 24 at 2,722.42 points, it has dropped 475.5, or almost 17.5%. On Friday, one of the big losers in the computer industry was Compaq, which lost more than 8.5% of its value on the day; it closed down $5.875 at $62.25. Also falling sharply was Microsoft, which dropped $5.75 to close at $64.75. Possibly feeling the crunch of ETA Systems’ new low-end supercomputers, Cray Research fell $4.25 to finish the day at $85. The giants of the industry also did not escape unscathed: IBM fell $5.125 at $135 even – and continued on down to shed another six bucks by midday yesterday, while Digital Equipment dropped $5.50 to $172.25 – and fell another $12 by mid-morning yesterday. Among the chipmakers, elated by their newly-pronounced recovery, the rout also made its mark: Intel fell $2.50 points at $52, Texas Instruments dropped $1.50 at $67.25, and National Semiconductor posted a $1.75 point drop to $17.25. Despite its decent earnings report on Wed-nesday, Apple also felt the heat, losing $4 to end at $48. Telex slipped below the $65 a share offer from Asher Edelman, dropping $5.50 to $62.125.