Saturday morning Intel and Google said hundreds of employees based in Japan are safe, and the damage to their facilities there is not significant.
Microsoft and Panasonic are still assessing damages.
But at least one Sony factory has been damaged by flooding.
A California industry analyst says the biggest impact will be felt in chip manufacturing especially the flash memory chips used to for storage of photos in cameras and cell phones, plus music in iPods and MP3 players.
Analysts say it could be weeks before the real impact is sorted out.