Z64K Beta (2018/07/31) is released. Pixel exact emulation of the Commodore 64, VIC 20 and Atari 2600 written entirely in Java. The emulators should run on any platform with an updated java runtime environment installed.

Z64K Changelog:
Add command line options for selecting 80 column mode and dual screen for c128 at startup.
-80
-dualscreen
eg. java -jar Z64K.jar c128 -80 -dualscreen will start the C128 emulator with dual screens with 80 column mode enabledin the main screen.
repositioned disk preview window to right side of file chooser.

Download: Z64 Beta (2018/07/31)
Source:Here