All the Bible websites that I know of have updated their NIV Bibles to the 2011 version. I used to use biblestudytools.com to access the 1984 version, but it now looks like it also has been updated to the 2011 version.
Can anyone point me to a site that still hosts the 1984 version? Or perhaps an eBook or other electronic means of accessing it? Whether free or for a price.