Background color, 46 Barrel Shifter, 179 BBUSY, 222 Beam comparator, 124 Beam position, --> Beam position counter, 216 BEAMCON0, 298 , 305 Bitplanes, --> Blitter, --> Blitter Busy, 186 Blitter registers - in line-drawing mode, 189 Blitter shifting, 179 BLTAxWM, 180 BLTCON0, --> BLTCON0L, 298 BLTCON1, --> BLTEN, 222 BLTPRI, 222 BLTSIZE, 169 , 171-173 , 186-187 , 191 , 308 BLTSIZH, 298 BLTSIZV, 298 , 308 BLTxDAT, 170 BLTxMOD, 172 BLTxPTH, 170 , 298 BLTxPTL, 170 BPL1MOD, 62 , 64 BPL2MOD, 62 , 64 BPLCON0, --> BPLCON1 - setting scrolling delay, 85 BPLCON2, --> BPLCON3, 298 BPLCONx, 90 , 307 BPLEN, 222 BPLxMOD, 84 , 91 BPLxPT, 91 BPLxPTH, 52 , 54 , 61 , 74 BPLxPTL, 52 , 54 , 61 , 74 BPUx, 48 , 87 , 90 Bridgeboard, 7 BZERO, 222