diff --git a/PDP11/pdp11_io_lib.c b/PDP11/pdp11_io_lib.c
index fdbb6cd9..7e7e566f 100644
--- a/PDP11/pdp11_io_lib.c
+++ b/PDP11/pdp11_io_lib.c
@@ -352,7 +352,7 @@ AUTO_CON auto_tab[] = {
     { { NULL }, 1, 2, 8, 8 },                           /* DU11 */
     { { NULL }, 1, 2, 8, 8 },                           /* DUP11 */
     { { NULL }, 10, 2, 8, 8 },                          /* LK11A */
-    { { "DMC" }, 1, 2, 8, 8 },                          /* DMC11 */
+    { { "DMA", "DMB", "DMC", "DMD" }, 1, 2, 8, 8 },     /* DMC11 */
     { { "DZ" }, DZ_MUXES, 2, 8, 8 },                    /* DZ11 */
     { { NULL }, 1, 2, 8, 8 },                           /* KMC11 */
     { { NULL }, 1, 2, 8, 8 },                           /* LPP11 */
@@ -369,7 +369,7 @@ AUTO_CON auto_tab[] = {
     { { "RX", "RY" }, 1, 1, 8, 4, {IOBA_RX} , {VEC_RX} }, /* RX11/RX211 */
     { { NULL }, 1, 1, 8, 4 },                           /* DR11W */
     { { NULL }, 1, 1, 8, 4, { 0, 0 }, { 0 } },          /* DR11B - fx CSRs,vec */
-    { { NULL }, 1, 2, 8, 8 },                           /* DMP11 */
+    { { "DMP" }, 1, 2, 8, 8 },                          /* DMP11 */
     { { NULL }, 1, 2, 8, 8 },                           /* DPV11 */
     { { NULL }, 1, 2, 8, 8 },                           /* ISB11 */
     { { NULL }, 1, 2, 16, 8 },                          /* DMV11 */