The core changes in detail:

Differences from Beta-7a to Beta-7b
- Fixed REU, transfer length register is 1 after a transfer completes.
- Fixed REU 512K wrap around
- Fixed cache controller preventing corruption when accessing 0x1FFFF0000 - 0x1FFFFFFFF
- Faster SDRAM controller. More memory bandwidth for turbo.
- Added slowdown modes to the Turbo settings. Offering CPU speeds of 25%, 50%, 75% and 100%.

Differences from Beta-7 to Beta-7a
- Emulated REU can write to I/O area (color-RAM)

Differences from Beta-6g to Beta-7
- Support for the docking-station.
- Fixed cpu-speed readout problem on VGA (since beta-6g)
- Fixed NMI issue in cartrigde mode (Sample playback in Ghostbusters and Imp.Mission)
- Fixed lot of REU issues (code corruption, BA, FF00 flag). The REU can now also be used in turbo mode.
- Fixed detection of long press (timeout is now the documented 0.8 sec)
- Added Turbo I/O. Speeds up certain I/O accesses in turbo mode.
- Complete new mixer stage in the SID emulator. Less artifacts on low volume and louder/clearer sound.
- Added small DC offset in mixer stage to improve sample playback on emulated SID.
- Improved envelope generator of the SID emulator.
- MMU improved to speed-up turbo (slightly)

Differences from Beta-6f to Beta-6g
- Implemented bit-fade in SID when no waveform is selected.
- Implemented bit-fade in SID when reading write-only registers.
- Added bits to detect in menu when disk-images need update after write actions by the emulated drives.
- Implemented "door" on emulated drive, when open drive will read dummy bytes.
- Fixed CPU instruction timing bugs discovered when comparing emulated 6510 against real 6510.
- CPU irq/nmi timing fixes.
- Implemented bit-fade on I/O port of emulated 6510.
- Fixed SID stereo mapping for D500 and D700.
- Four timers added at addresses D0AA to D0AD for menu (it can't use CIA timers when freezing).

Differences from Beta-6d to Beta-6f (includes 6e changes):
- Improved emulation of illegal opcodes SHX and SHY.
- Support backwards reading of the PS/2 keyboard matrix.
- VIC-II emulation fix for line 0x138 which does not exist on PAL (line 0x137 is 1 cycle longer).
- Implemented lightpen trigger from emulated CIA for stable rasters effects.
- Fixed vertical sprite stretching bug in VIC-II emulation.
- Preliminary docking station support. 

Differences from Beta-6c to Beta-6d:
- Cartridge emulations
        Business Basic, S'More, Prophet-64, Capture, Mach-5, Westermann Learning,
        Epyx Fastload, Easy-flash, PageFox
- Turbo speed increase: Eliminated one clock cycle from critical path
- Turbo speed increase: Writes to memory concurrent with next instruction fetch
- Turbo speed increase: MMU caches last used CPU slot

Differences from Beta-6b to Beta-6c:
- Auto speed option for turbo feature. Slows down on IEC bus accesses - GEOS works now!
- PS/2 Page up/Page down alias for F1, F7. Easier navigation in the File-Browser.

Differences from Beta-6 to Beta-6b:
- 1541 emulation: fixed IEC timing. All known speedloader problems are gone now.
- 1541 emulation: VIA6522 timer fixes
- 1541 emulation: VIA6522 register r/w fixes
- new cartridge emulations: Mikro Assembler, StarDOS

Differences from Beta-5b to Beta-6:
- Fixed RAM mirrors for 1541 drive emulation
- Fixed reading from emulated SID
- cartridge emulations
        KCS power, SSv5, C64GS, Comal-80, Zaxxon, Ocean type 1,
        Simons Basic, Fun play, Super Games, Warp Speed,
        Dinamic and Magic Desk.
- Disk track lengths set to 6256, 6672, 7144 or 7696 bytes.
- Implemented disk-change with button.
- Input latch emulation in VIA emulation
- Implemented SDR register in CIA
- Implemented real IEC bus disable bit.
- VIC-II timing fixed for mode bits (MCM, BMM and ECM)

Differences from Beta-5a to Beta-5b:
- Eliminate spurious resets by masking reset line in standalone mode.
- Fix keyboard matrix so joysticks are properly emulated (IR, numpad) in standalone mode.
- Block normal button functions in menu mode (only exception is reboot by pressing 0.7s on right button)

Differences from Beta-5 to Beta-5a:
- Fix crash when turbo limit is set in menu without activating turbo.
  (or when disabling active turbo with button while a limit is set)
- Fix D030 mirror of the turbo bit emulating C128 2Mhz mode with Chameleon turbo.

Differences from dev-5 to beta-5:
- Speedup of turbo (MMU caches most recent used value)
- Speedup of turbo by eliminating one clock cycle from critical path
- I/O port status added to VGA debug bar
- Hard-reset in menu forces reboot to prevent possible MMC cart curruption
- Left button can perform various functions (menu, expert cartridge switch, turbo)
- TOD clock fixes. Support 50Hz and 60Hz depending on VIC-II type.
- Turbo has configurable speed limit (2x, 3x.. 6x)
- Button debounce improved (less likely to see multiple presses).
- non-turbo CPU speed in standalone mode more accurate: 
  Switches depending on VIC-II type between 0.985 and 1.022 Mhz
- VGA output is double-buffered to eliminate tearing effects when picture is scrolling.
- Memory areas can be made read-only with highest bit of MMU.

Differences from beta-4 to dev-5:
- Framebuffer writes now use MMU.
- Framebuffer writes can be switched off (buffer can be used by software)
- Cartridge buttons emulated on PS/2 keyboard (F11,F12 and PrintScreen)
- Chameleon can use real BASIC and Kernal ROMs in machine in cartridge mode.
- Emulated IEC bus can be disconnected from C64 (Chameleon is drive emu)
- FLI bug fixed
- Added Stereo SID support
- Turbo feature added
- Relative CPU speed displayed in VGA debug bar.
 
