int n_aichan;           /*  num of A/D chans */
        int n_aichand;          /*  num of A/D chans in diff mode */
        int n_aochan;           /*  num of D/A chans */
-       int ao_maxdata;         /*  resolution of D/A */
        const struct comedi_lrange *rangelist_ai;       /*  rangelist for A/D */
        const char *rangecode_ai;       /*  range codes for programming */
        const struct comedi_lrange *rangelist_ao;       /*  rangelist for D/A */
                .n_aichan       = 16,
                .n_aichand      = 8,
                .n_aochan       = 2,
-               .ao_maxdata     = 0x0fff,
                .rangelist_ai   = &range_pci1710_3,
                .rangecode_ai   = range_codes_pci1710_3,
                .rangelist_ao   = &range_pci171x_da,
                .n_aichan       = 16,
                .n_aichand      = 8,
                .n_aochan       = 2,
-               .ao_maxdata     = 0x0fff,
                .rangelist_ai   = &range_pci1710hg,
                .rangecode_ai   = range_codes_pci1710hg,
                .rangelist_ao   = &range_pci171x_da,
                .cardtype       = TYPE_PCI171X,
                .n_aichan       = 16,
                .n_aochan       = 2,
-               .ao_maxdata     = 0x0fff,
                .rangelist_ai   = &range_pci17x1,
                .rangecode_ai   = range_codes_pci17x1,
                .rangelist_ao   = &range_pci171x_da,
                .name           = "pci1720",
                .cardtype       = TYPE_PCI1720,
                .n_aochan       = 4,
-               .ao_maxdata     = 0x0fff,
                .rangelist_ao   = &range_pci1720,
        },
        [BOARD_PCI1731] = {
                s->type = COMEDI_SUBD_AO;
                s->subdev_flags = SDF_WRITABLE | SDF_GROUND | SDF_COMMON;
                s->n_chan = this_board->n_aochan;
-               s->maxdata = this_board->ao_maxdata;
+               s->maxdata = 0x0fff;
                s->len_chanlist = this_board->n_aochan;
                s->range_table = this_board->rangelist_ao;
                switch (this_board->cardtype) {