A new version of Kat5200 has been released so I thought I'd add a thread about this emulator for this Atari 5200 (as well as the Atari 8-bit computers [800/XL/XE]) here.  Here are the notes for the current version (0.7.1): 

This release contains the following bug fixes and changes:

  * Fixed: Xbox360 style controllers cause Auto-Detect exit in GUI
  * Fixed: GUI Stick Left not set on first try
  * Fixed: Controls can get fixed up when setting up multiple players
  * Fixed: Keyboard setup for keys with Up/Down/Left/Right in name
  * Fixed: Screen colors in video config preview window
  * Update: Mouse Wheel in GUI lists works
  * Fixed: Check for SDL2 version 2.0.5 and disable function if older (SDL_SetWindowResize)
  * Fixed: multiple controllers control player 1 on startup
  * Fixed: Player 3/4 keypad not working
  * Fixed: Player 3/4 axis weirdness (Simulate Analog forced on)
  * Fixed: Bounty Bob works again (and works for 8-bits)
  * Fixed: Unified Win32 release (XP and above works with one build)

Download Here