What's New? 2.6.6

Released -- 26 August 2023

The 2.6.6 release is mainly a maintenance update for the mappers and emulation core with a few new features added in. Some of these new features apply only to the Qt/SDL version of the GUI.



  • Minor refactor of the save game RAM code. Fixes UNROM-512 flash clearing bug during movie play.
  • Mapper 354: Add CHR-RAM protect.
  • Mapper 78: Add submapper support.
  • Added mapper 174 support.
  • Move mapper 205 to mapper 361/366, added proper mapper for 205.
  • Mapper 205: Fix for split-rom variant (UNIF)
  • Changed UNROM-512 to use 8kB of CHR-RAM memory by default.
  • Mapper 342 memory optimization.


  • Implemented LUA function memory.registerread.


  • Memory initialization settings are now also applied to nametable, palettes, and sprites.
  • Fixed bug were write instructions didn't always update the databus.



  • Added ld65 debug file symbol loader feature.
  • Added checkbox to Qt debugger menu to control trace logger auto start function on debugger open.
  • Added code to stop the trace logger on debugger close if it was the debugger who started it in the first place.
  • Added address validity checking to the breakpoint editor dialog entry fields.


  • Added a third video driver option that uses a QPainter object to render QImages to the viewport (uses a pure Qt API).
  • Fixed video transparency issue that has been seen on some platforms (Wayland) by forcing alpha bits to be set to full opaque.


  • Added state recorder feature, periodically saves time history of game play states that can be recalled and played out from.
  • Fixed bug regarding force grayscale or use custom palette settings change not updating PAL 3x filter appropriately.
  • Added feature that allows loading of save state files via drag n drop file dialog operations.
  • Fixed redundant window focus bug that would occur when attempting to open a pre-existing window.
  • Added optional cross-platform libarchive interface to allow Qt GUI to open ROMs from 7zip archives.
  • Minor improvements to the ROM selection from archive dialog.
  • Improved frame scheduling timing precision.


  • Build fixes for GCC 13.

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