New command line switch allows defining a system logical device that will be searched ahead of SYS:, CMD:, and BAS:

-mntsys dev:=path

For example:

ashell -i /vm/miame.ini -mntsys asr63:=/vm/miame63/dsk0 log sys:

Assuming the specified path /vm/miame63/dsk0 existed and contained 001004, 002002, and 007006 directories, these would be search prior to the corresponding dsk0:[1,4], dsk0:[2,2] and/or dsk0:[7,6] directories.

This can be useful in situations where you want to test a new version of A-Shell without overwriting your existing DSK0: directories.