Files with g1m file extension can be found as program sources for Casio 9860 family of graphics calculators.
G1M file extension - Casio Model 9860 BASIC program
What is g1m file? How to open g1m files?
File type specification:
The g1m file extension is mainly related to Casio Model 9860, a graphical calculator introduced with 2005.
The g1m file contains program source files for the device. Used for example for UBS transfers.