Before you post a question, try SEARCHING for an answer within this site. Look in this forum for the postings on Driver for Canon I850. There you will find an entire string of information. One posting in this thread has a link to a Canon Japan FTP site with many drivers for Linux.
Another possible source is Turboprint.
Turbo print says it supports the ip1500 you could download the free version and try it. The site also has a feedback form for when they don't support a printer. It is well worth the effort to try.