return n;
 }
 
+static int vmk80xx_di_bits(struct comedi_device *cdev,
+                          struct comedi_subdevice *s,
+                          struct comedi_insn *insn, unsigned int *data)
+{
+       struct vmk80xx_usb *dev = cdev->private;
+       unsigned char *rx_buf;
+       int reg;
+       int retval;
+
+       dbgvm("vmk80xx: %s\n", __func__);
+
+       retval = rudimentary_check(dev, DIR_IN);
+       if (retval)
+               return retval;
+
+       down(&dev->limit_sem);
+
+       rx_buf = dev->usb_rx_buf;
+
+       if (dev->board.model == VMK8061_MODEL) {
+               reg = VMK8061_DI_REG;
+               dev->usb_tx_buf[0] = VMK8061_CMD_RD_DI;
+       } else {
+               reg = VMK8055_DI_REG;
+       }
+
+       retval = vmk80xx_read_packet(dev);
+
+       if (!retval) {
+               if (dev->board.model == VMK8055_MODEL)
+                       data[1] = (((rx_buf[reg] >> 4) & 0x03) |
+                                 ((rx_buf[reg] << 2) & 0x04) |
+                                 ((rx_buf[reg] >> 3) & 0x18));
+               else
+                       data[1] = rx_buf[reg];
+
+               retval = 2;
+       }
+
+       up(&dev->limit_sem);
+
+       return retval;
+}
+
 static int vmk80xx_di_rinsn(struct comedi_device *cdev,
                            struct comedi_subdevice *s,
                            struct comedi_insn *insn, unsigned int *data)
        return n;
 }
 
+static int vmk80xx_do_bits(struct comedi_device *cdev,
+                          struct comedi_subdevice *s,
+                          struct comedi_insn *insn, unsigned int *data)
+{
+       struct vmk80xx_usb *dev = cdev->private;
+       unsigned char *rx_buf, *tx_buf;
+       int dir, reg, cmd;
+       int retval;
+
+       dbgvm("vmk80xx: %s\n", __func__);
+
+       dir = 0;
+
+       if (data[0])
+               dir |= DIR_OUT;
+
+       if (dev->board.model == VMK8061_MODEL)
+               dir |= DIR_IN;
+
+       retval = rudimentary_check(dev, dir);
+       if (retval)
+               return retval;
+
+       down(&dev->limit_sem);
+
+       rx_buf = dev->usb_rx_buf;
+       tx_buf = dev->usb_tx_buf;
+
+       if (data[0]) {
+               if (dev->board.model == VMK8055_MODEL) {
+                       reg = VMK8055_DO_REG;
+                       cmd = VMK8055_CMD_WRT_AD;
+               } else { /* VMK8061_MODEL */
+                       reg = VMK8061_DO_REG;
+                       cmd = VMK8061_CMD_DO;
+               }
+
+               tx_buf[reg] &= ~data[0];
+               tx_buf[reg] |= (data[0] & data[1]);
+
+               retval = vmk80xx_write_packet(dev, cmd);
+
+               if (retval)
+                       goto out;
+       }
+
+       if (dev->board.model == VMK8061_MODEL) {
+               reg = VMK8061_DO_REG;
+               tx_buf[0] = VMK8061_CMD_RD_DO;
+
+               retval = vmk80xx_read_packet(dev);
+
+               if (!retval) {
+                       data[1] = rx_buf[reg];
+                       retval = 2;
+               }
+       } else {
+               data[1] = tx_buf[reg];
+               retval = 2;
+       }
+
+out:
+       up(&dev->limit_sem);
+
+       return retval;
+}
+
 static int vmk80xx_cnt_rinsn(struct comedi_device *cdev,
                             struct comedi_subdevice *s,
                             struct comedi_insn *insn, unsigned int *data)
        s->n_chan = dev->board.di_chans;
        s->maxdata = 1;
        s->insn_read = vmk80xx_di_rinsn;
+       s->insn_bits = vmk80xx_di_bits;
 
        /* Digital output subdevice */
        s = cdev->subdevices + VMK80XX_SUBD_DO;
        s->n_chan = dev->board.do_chans;
        s->maxdata = 1;
        s->insn_write = vmk80xx_do_winsn;
+       s->insn_bits = vmk80xx_do_bits;
 
        if (dev->board.model == VMK8061_MODEL) {
                s->subdev_flags |= SDF_READABLE;