Agnus/ Read/ Denise/ Register Address Write Paula Function -------- ------- ----- ------- -------- DSKPTH 020 W A( E ) Disk pointer (high 3 bits, high 5 bits if ECS) DSKPTL 022 W A Disk pointer (low 15 bits) This pair of registers contains the 18-bit address of disk DMA data. These address registers must be initialized by the processor or Copper before disk DMA is enabled.