The phrase "a computer on a" is correct and usable in written English.
It can be used when referring to a specific context involving a computer and another object or situation that follows the phrase.
Example: "I found a computer on a desk in the corner of the room."
Alternatives: "a computer at a" or "a computer in a".
As Benjamin Moser noted in his post about the Susan Sontag archives, the influx of digital written material has presented a challenge to archivists: Outside of just setting a computer on a table like some sort of oversized paperweight, how does one present a writer's computer to the public?
Beyond the desk, out of sight, is a computer on a trolley, and there's a swivelling stool between the two - one of those kneeling stools for people with back trouble.
If you have to use a computer on a gig you need to consider machines that are made for only one purpose, playing back music.
If you need a computer on a particular date and time, please call (360) 442-2571.
The box will be powered by the National Semiconductor Corporation's GX processor, a computer on a single chip.
Products that let you play video from a computer on a TV have also been around for a while.
2012: COMPUTER ON A CHIP "The high-end microprocessor of 2020 will be an entire computer on a single chip: processor and main memory versus the many processor chips and DRAM chips of today".
Listen from a computer, on an iOS device or on an Android device.
Below the level of the governor, I never saw a computer on an official's desk.
Sitting in front of a computer on an elevated stage, Mr. Jobs seemed to strike the pose of a concert pianist as he showed a series of new computers and programs.
Web designers and theorists have long talked about the democratization of publishing on the Internet, the fact that the web puts anyone with a computer on an equal footing with the elite that traditionally has owned the printing presses.
