Looking for some computer/GPS help

As you may have heard, your older GPS may have "issues" starting tomorrow:

https://arstechnica.com/information...vent-on-april-6-could-have-some-side-effects/

I have several Garmin units and in speaking with Garmin today my two older Rino 530HCXs are affected. Since I've recently switched to an iMac I no longer have the option to d/l the software updates. (it doesn't work on Macs)

Anyone out there with a (preferably Windows 7 OS) willing to help a guy out ?

Mahalo