* Fix: Version 0.2.5 (first 64-bit Mac OS version) does not work on Mac OS El Capitan and Sierra.
    NOTE: 0.2.6 should work on Mac OS 10.11 through 10.15 (El Capitan, Sierra, High Sierra, Mojave, and Catalina). It will NOT work on Mac OS 10.10 (Yosemite) or earlier. Unfortunately, in order to support Catalina we had to switch to the 64-bit Metal graphics framework that became available in Mac OS 10.11 (El Capitan).
* Fix: Persistence on the ED1 got broken in VM v66.
* Revised the "reserved pin" list for ED1 to avoid accidental conflict between GPIO and internal components such as the TFT display and motor controller. It is safe to use MicroBlocks to read or write any pin; the reserved pins simply don't do anything. Use pin numbers 1-4 with the pins marked D1-D4 and A1-A4 on the board.