ACCESS_PORT
bpck6_send_cmd(pi, port | ACCESS_PORT | ACCESS_READ);
bpck6_send_cmd(pi, port | ACCESS_PORT | ACCESS_WRITE);
bpck6_send_cmd(pi, ATA_REG_DATA | ACCESS_PORT | ACCESS_WRITE);
bpck6_send_cmd(pi, ATA_REG_DATA | ACCESS_PORT | ACCESS_READ);