gb/gbc
 

if u replace this file <SPMP_N1.bin> by this file <SPMP_G1_12M.bin> ,by renaming , u can use gb/gbc on your pmp (which can be programmed with C# :D ) i did it and it works like , ok a few graphic glitches in a few roms but emulates pretty good ;)
and then you can get the gbdk (game boy development kit) and it's tile builder and map builder and good to go with C#
& notepad :D (yeah i signed up only to post this and help you all :) in the little ways i can )