Multnomah County Library has about 1000 public PCs at its 19 neighborhood locations as well as laptops to use within each library. Learn more about the library's computer services and policies. With a library card or current, valid photo ID, all patrons and visitors can use library computers for 4 hours per day. Computers can be used from opening until 10 minutes before closing. Mobile / wireless printing from almost any internet-enabled mobile device.