Running an iMac and have a HP Deskjet J610a. Just upgraded operating system from Mt Lion to Yosemite. Printer is now off line and I can't bring it up. Downloaded Apple upgrade for printer with no results.
You are right. The drivers for printers are provided through the Apple Update. However, you can download and manually install the drivers for supported printers. The package is available for Mac OSX Lion or later.
The driver supports HP Deskjet J610a Series device.