I'm a semi-retired graphic artist. I'm currently running MAC OS X 6.6.8 but internet issues are forcing me toward Yosemite. I know I will have to upgrade my Quark Xpress to the latest version but I'm not sure about Photoshop CS5.1. Please advise. Thanks ahead of time.
Photoshop CS5 will work, but you'll need to reinstall Photoshop after installing the MacOS 10.10 update to replace files damaged by the OS installer, and install the JAVA version that Apple tells you to install.