I have been using my IDE 1.6.4 to program Adafruit Trinkets. I installed their board drivers from github using the IDE board manager. Yesterday I successfully programmed an ATTiny85 using my Uno as the ISP and Dave Mellis' board driver from Github. I am excited about this.
My problem is in installing Dave's drivers it removed my Adafruit drivers from the board list. Fortunately I had WiFi available when I discovered this and I was able to reinstall Adafruits drivers. I do not always have a network available to access github to swap drivers.
At this point all I can do is enter the githib address in the Additional Board Manager URL found in Preferences. How do I get around this? I assume these files still reside on my hard drive. How do I identify them and direct IDE to use them as needed?