WD_DATA
lun = read_wd33c93(regs, WD_DATA);
read_wd33c93(regs, WD_DATA);
x = read_wd33c93(regs, WD_DATA);
*buf++ = read_wd33c93(regs, WD_DATA);
write_wd33c93(regs, WD_DATA, *buf++);