OPL4 External Memory Format
0000h D 1 D 0 S21 S20 S19 S18 S17 S16
0001h S15 S14 S13 S12 S11 S10 S09 S08
0002h S07 S06 S05 S04 S03 S02 S01 S00
0003h L15 L14 L13 L12 L11 L10 L09 L08
0004h L07 L06 L05 L04 L03 L02 L01 L00
0005h E15 E14 E13 E12 E11 E10 E09 E08
0006h E07 E06 E05 E04 E03 E02 E01 E00
0007h 0 0 LF2 LF1 LF0 VI2 VI1 VI0
0008h AR3 AR2 AR1 AR0 D13 D12 D11 D10
0009h DL3 DL2 DL1 DL0 D23 D22 D21 D20
000Ah Rc3 Rc2 Rc1 Rc0 RR3 RR2 RR1 RR0
000Bh 0 0 0 0 0 AM2 AM1 AM0
... til 383.
00 - 8bit 01 - 12bit 10 - 16bit