Translation:He played with the computer all afternoon.
no, because I seem not to be able to access them. Your link works, but if I simply press the "discuss" button, I land here, on a page where even my original question wasn't there, so I repeated it. That happens quite often, btw.: even when it shows a number of discussion entries in brackets the link goes to an empty page!
"He played all afternoon with the computer" I would suggest is right in UK English despite mr bass' explanation. I would here similar constructions quite often with the placement of "all afternoon" at the end of a sentence. I am pressing, again, the my answer should be right button.