WinUAE v2.4.0 Beta 21 is released. WinUAE is the commodore amiga emulator for Windows. WinUAE is a mostly complete software emulation of the hardware of the Commodore Amiga 500/1000/2000. A Commodore Amiga, for those who don’t know, is a 16/32 bit computer system based on the Motorola 680×0 CPU and a few specially designed custom chips that provide very good graphics and sound capabilities. Its first incarnation, the A1000, appeared in 1985, followed by the highly successful A500 and A2000 models. WinUAE is a port of the originally written for Unixish systems UAE; but over time, it seems the Windows port, WinUAE has become the best version available on any platform. WinUAE is free software: you are welcome to distribute copies of it and/or modify it, under certain conditions. There is no warranty of any kind for UAE. For more details concerning these issues, please read the GNU General Public License, which describes the terms under which WinUAE is distributed.

WinUAE v2.4.0 Beta 21 Changelog:
- Direct3D masks and scanlines fixed, forgotten testing code.. (b20)
- 2.3.2 "stop the cpu and wait until blitter has finished if any blitter register is accessed while blitter is busy and cpu mode is fastest possible" was broken and could cause side-effects in some situations.
- Direct3D to DirectDraw fallback if DirectX is not recent enough crashed. (b5)
- Keyboard lost sync state emulated, needed with some programs that don't handshake all buffered key codes but still clear the CIA keyboard interrupt flag, this caused dead keyboard after b1 update. Now keyboard should be fully emulated.
- Quickstart panel disk insert always reset track position to zero. (forgot to restore old track after checking disk type and bootable state, bug since Quickstart was introduced!) Fixes Wrath of Demon disk swaps.
- Z2 RTG changes broke chip RAM "memory barrier" causing crash if JIT executed code at the very end of chip RAM. (b16)
- Huge improvement in fastest possible CPU (with or without JIT) + low latency vsync performance.
- Fastest possible without JIT performance improved in non-vsync modes. It now executes small chunks of extra code after each scanline instead (as long as there is time, the faster the host CPU, the more extra time there is) of single huge chunk just before vsync. JIT basically does the same but because it has "unknown" timing, it may execute "too much" code first and then skip multiple scanlines until there is enough time again.
- Immediate blitter is now 100% immediate. Fastest possible (with or without JIT) performance greatly improved (10x+ possible!) if program does lots of small blits. Previously, even in immediate blitter mode, blitter wait caused CPU emulator to waste its extra "fastest possible time slot" by doing absolutely nothing else than waiting the blitter that never happened. It can't happen until next scanline, during extra fastest CPU "slots" chipset emulation has to be paused.

Download: WinUAE v2.4.0 Beta 21
Source: Here