This is version 0.51d which includes some bugfixes/minor additions (compared to 0.51c):
- Eye of the Beholder: fix for NTSC C64 and C128 incl. turbo mode (might need timing adjustments, look at sidekick64.cfg)
- Tuned Simons Basic (Magic Desk cart) fixed
- SID/FM-emulation HDMI-output fixed
- added support for second FM-digi-channel
Sidekick64 v0.51 features/updates:
- MOD/YM/WAV Player (up to 48kHz stereo with dual SID-setups)
- low-latency HDMI-audio output for SID-/FM-/MIDI-emulation
- added YM3526/OPL sample playing emulation
- user-defined Logos for freezers/kernals
- hiding C128-specific folders on C64
- fixed GeoRAM not-saving-bug
Source: Github