Currently Being ModeratedApr 8, 2013 11:14 AM (in response to ralphiedee)
Over 20 views and no response which means I should know this?
It means a) 20 people needed to read your message to find out your question was about the Viewport, since you did not mention that in your title, and b) none of them knew the answer.
You're not talking to Apple here, just other users like yourself who volunteer to help where they can. There is no guarantee any of them will know more about viewports than you do.
I'd suggest searching google on "fixed layout epub viewport" and see if you find something userful there.