Shop for smart card reader for mac best buy at Best Buy. Find low everyday prices and buy online for delivery or in-store pick-up. I recently bought a CAC reader so I could log into AKO and I have no idea how to use it. I use a MacBook pro so I'm not sure if I need software or what but i'm doing something wrong. MacBook Pro (Retina, 15-inch, Mid 2015) macOS Sierra 10.12.2. What is interesting is that I'm getting the same message whether the CAC reader is plugged in or not when trying to access these sites. But, I can see the proper CAC Keychain and certificates when the CAC reader is plugged in with the CAC inserted. Best Regards, Albert. Nov 01, 2006 I would check to make sure you have a process named 'CAC' running - this is the software that talks to the card. If you don't have a process named CAC, your card reader firmware may be out of date. You should update the firmware (using a PC works best). A lot of old SCR331 readers need a firmware update. The steps involved to electronically sign a PDF using Preview on Mac are quite simple and will save you valuable time, especially if you have multiple documents, contracts, forms or other.