The phrase "a time when computer" is not correct as it is incomplete and lacks a noun or context to make it usable in written English.
You can use it when referring to a specific period related to computers, but it needs to be completed for clarity.
Example: "There was a time when computers were not as advanced as they are today."
Alternatives: "an era when computers" or "a period when computers".
Their moves come at a time when computer sales have slowed from their heady days of the '90s and the market is becoming increasingly saturated.
As brain researcher and Palm inventor, Jeff Hawkins, at Numenta pointed out, there was a time when computer scientists thought they could create artificial intelligence algorithmically.
At a time when computer science enrollments are declining in some developed nations and students don't see technology as being as cool as it once was, these students go back to their countries and get the reception that even rock stars would be jealous of.
It was not until the late 1960s, at a time when computer scientists had started to consider whether programs could be proved correct, that On Computable Numbers came to be widely regarded as the seminal paper in the theory of computation.
Samples and loops played a key part at a time when computer programs could not yet adequately perform such functions.
Stories make games compelling, and interactive fiction is an old, old genre born in a time when computers were barely more functional than staplers.
At a time when computers were still relatively unknown in regular homes, the Nicholses had several, lined up in a room off the living room where Mr. Nichols also kept a police and fire scanner running at all times.
The mid-nineties were a time when computers and the Internet still felt exhilarating and a little bit dangerous, mostly because nobody could predict what the revolution that they represented might beget.
Films that used cutting edge special effects to imagine advanced technologies in distant galaxies at a time when computers were still in their infancy, yet still looked more realistic than many of today's pixel-fests.
The imprecation on its home page, "don't touch the mouse!", gives one some immediate understanding that Xanadu isn't intended to be like just another webpage.Xanadu's singular genius, Ted Nelson, who turned 77 today, began work on it at a time when computers were scarce, expensive and capable only of simple tasks.
