a7800DS v4.2 is released. a7800DS is an Atari ProSystem 7800 console emulator for the DS/DSi. a7800DS is based on ProSystem. To use this emulator, you must use compatibles rom with a78/bin format.

a7800DS v4.2 changelog:
Added support for bankswitched RAM (32K of RAM switched in 16K chunks). This makes the Ex version of 1942 playable.
Added alternate way of handling bankswitched RAM the same way as the DragonFly cart or SN board: via writes to 0xFFFF.
Fix graphical glitch for Ballblazer (just hiding it off screen).
Numerous small updates to the internal cart database to ensure game run with the proper settings (mostly High Scores)
New 8x density on the High Score Cart - transparent to the user but provides more slots so the HSC won't fill up.
Flat 32K plus RAM cart type supported.
Pokey @800 supported for upcoming homebrews.

Download: a7800DS v4.2
Source: Here