The old IDE’s are 16 bit, meaning the commands that use timing are in mS resolution. The new IDE’s are 32 bit, meaning the commands are in uS resolution. Note: There really isn’t any incompatibility between 16bit and 32bit. What did change however were almost all timing arguments are now in microseconds instead of milliseconds. The only ones that did NOT change are, pause and pauseus (since it was already in microseconds). All other functions which had a timing argument in milliseconds is now in microseconds.