SHADDR
data_addr = ahd_inq(ahd, SHADDR);
ahd_outq(ahd, SCB_DATAPTR, ahd_inq(ahd, SHADDR));
ahd_inl(ahd, SHADDR+4),
ahd_inl(ahd, SHADDR),
data_addr = (ahc_inb(ahc, SHADDR + 3) << 24)
| (ahc_inb(ahc, SHADDR + 2) << 16)
| (ahc_inb(ahc, SHADDR + 1) << 8)
| (ahc_inb(ahc, SHADDR));