FluBBa has released an updated version of his Master System emulator SMSAdvance for Gameboy Advance. Most games are running in full speed now!

Changes:

*Added copying of first 32kB ROM to VRAM for faster execution.
*Added selection of machine.
*Added correct noise generation for SG-1000 emulation.
*Added correct palette in TMS9918 modes on SMS machines.
*Added different vdp capabilities depending on selected machine.
*Added some very basic Mode5 support when Machine=MegaDrive.
*Added different io maps depending on selected machine.
*Added support for the SMS1 tilemap address masking (Ys(J)).
*Added support for turning on/off internal RAM.
*Added auto save of SRAM (if it’s allready present) when entering menu.
*Added auto turn off of Bios when no header found (on machine=Auto).
*Added auto region (Pop Breaker GG (J)).
*Fixed support for Dodgeball King (KR).
*Fixed pushing and poping of AF register (Adventure of Batman GG).
*Fixed sprite bugs in unscaled mode on Codemasters games.
*Fixed initializing of all CPU regs on reset.
*Fixed timing of HALT instruction.
*Fixed palette setting for TMS9918 modes on GG.
*Fixed noscrolling for TMS9918 modes.
*Fixed up Mode1 graphics a bit.
*Fixed correct HCounter and latching.
*Better switching between TMS9918 and SMS video modes.
*More info shown from the game header.
*Optimised tile rendering for mode 0 & 2 (for real this time).
*Optimised all Z80 memory reads, one instruction and cycle shorter.
*Optimised DAA opcode.
*Optimised DEC opcodes.
*Optimised SBC A/HL opcode.
*Optimised one of the SRA opcodes.
*Optimised CPI, CPD, CPIR & CPDR opcodes.

http://www.ndsretro.com/