Hi,
Do someone know how MGLS24064 with Arduino Mega works?
It might work with the u8g2 constructor
U8G2_T6963_256X64_1_8080
Wiring requires some knowledge and the datasheet http://www.mouser.com/ds/2/422/MGLS24064-239533.pdf does not tell you anything about how to wire this display.
You probably need an external negative voltage supply (somewhere between -10V and -15V) which has to be feed into V0 input through a wiper (if i remember correctly).
Just looking tough the internet, here is an example for the setup: http://www.aasi.net/development/datasheets/LCD_VFD/t6963tst.gif
For u8g2, you must connect FS to GND (8x8 font/memory layout)
Oliver