MMIO register table/DMA

See: DMA registers

Name	Address	Bits	Type	Notes
DMAPn	$43n0	DI.A APPP	RW8	Direction (D), indirect HDMA (I), address increment (A), transfer pattern (P).
BBADn	$43n1	AAAA AAAA	RW8	B-bus address.
A1TnL A1TnH A1TnB	$43n2 $43n3 $43n4	LLLL LLLL HHHH HHHH BBBB BBBB	RW24	DMA source address / HDMA table address.
DASnL DASnH DASnB	$43n5 $43n6 $43n7	LLLL LLLL HHHH HHHH BBBB BBBB	RW24	DMA byte count (H:L), HDMA table address (B:H:L).
A2AnL A2AnH	$43n8 $43n9	LLLL LLLL HHHH HHHH	RW16	HDMA table current address within bank (H:L).
NTRLn	$43nA	RLLL LLLL	RW8	HDMA reload (R) and scanline counter (L).
UNUSEDn	$43nB $43nF	DDDD DDDD	RW8	Unused shared data byte (D).