Item description:

ZXDS is an emulator of Sinclair ZX Spectrum for Nintendo DS, written by Patrik Rak. It is steadily reaching a mature stage of development, and it already has some noteworthy features, like accurate emulation of Spectrum 48k, 128k and Pentagon models (including sound), or support for TAP/TZX/PZX tape files, TRD/SCL disk files and RZX playback files.
Download and installation

Just download the archive using the link below, unpack it and copy the entire ZXDS directory (not just its content, but the directory itself) to the root of whatever device you use to run homebrew on your DS. Make sure that even the empty subdirectories are copied properly (in particular, make sure the /ZXDS/Saves directory is created, otherwise the save slots won't be saved permanently to your card). If you wish so, you may then relocate the ZXDS.nds to elsewhere on the card, like to the root itself, to make it more accessible.

ZXDS 0.8.1 beta 1 (27.11.2008)

+ RZX playback (no SZX snapshot support yet, though).
+ Files stored in ZIP archives can be browsed and loaded directly.
+ Support for poke cheats in POK file format, including autoload.
+ Added log screen for better problem diagnostics, especially those RZX related.
+ Turn off the bottom screen backlight after configurable timeout.
+ Automatically save state and enter sleep mode when the lid is closed.
* Alternatively boot from saves/boot.z80 instead of last session state.
* Skip loading of either state upon startup when L/R buttons are held.
* Replaced few busy loops with inactive waits to further improve battery life.
* Improved the last menu action to cycle through all recently used views.
* Extended the range of both AY and speaker samples to make the sound louder.
* Tweaked the Z80 snapshot loading code to support some less conformant files.

ZXDS 0.8.0 beta 1 (19.6.2008)

+ TR-DOS emulation, allowing loading of TRD/SCL disks (including autoboot).
+ For/next loops in TZX files are now supported.
+ Screenshot support, for SCR/BMP saving and SCR loading.
+ Color/grayscale palette toggle for more nostalgic look.
+ Mode for black and white display of ink/paper only, without attributes.
+ AY ACB and ABC stereo modes and narrow/wide stereo separation.
+ Choice of three relative AY and speaker volume levels.
* Changed AY volume tables to match the real machine more closely.
* Implemented fake low-pass AY filter to avoid aliasing issues in some tunes.
* Fixed setting of AY envelope register even if it doesn't change, fixes few sound effects.
* Fixed sound clamping when all AY channels played at full volume and speaker was off.
* Few other subtle changes (initial config autosave, even more safe shutdown).