bitbltbuf.dbw == 0:
-------------------
colors15
funslower
plasmadream
ps2mame
...

TEXA:
*****

RGBA16
		A=0		A=1
	AEM=0	TA0		TA1
	AEM=1	R=G=B=0>0	TA1
		R|G|B!=0>TA0

RGBA24
	AEM=0	TA0
	AEM=1	R=G=B=0>0
		R|G|B!=0>TA0

About the frame buffer and the dispfb "buffer"

Sometimes the application will use some 'double buffering' when he write on screen, and will specify different
frame buffer memory space (with the same context or differents contexts) to draw in. Then the plugin must take
care of these "different" frame buffer else it will cause flickering (psms, pillgen, p51, ...).
