diff --git a/VAX/vax630_sysdev.c b/VAX/vax630_sysdev.c
index 3e04b2cd..3160b4ec 100644
--- a/VAX/vax630_sysdev.c
+++ b/VAX/vax630_sysdev.c
@@ -756,7 +756,9 @@ struct reglink regtable[] = {
     { ROMBASE, ROMBASE+ROMSIZE+ROMSIZE, &rom_rd, NULL },
     { NVRBASE, NVRBASE+NVRASIZE, &nvr_rd, &nvr_wr },
     { KABASE, KABASE+KASIZE, &ka_rd, &ka_wr },
+#if !defined(VAX_620)
     { QVMBASE, QVMBASE+QVMSIZE, &vc_mem_rd, &vc_mem_wr },
+#endif
     { QBMBASE, QBMBASE+QBMSIZE, &qbmem_rd, &qbmem_wr },
     { 0, 0, NULL, NULL }
     };
diff --git a/VAX/vax_lk.c b/VAX/vax_lk.c
index 29b6ef58..60782078 100644
--- a/VAX/vax_lk.c
+++ b/VAX/vax_lk.c
@@ -28,6 +28,8 @@
    11-Jun-2013  MB      First version
 */
 
+#if !defined(VAX_620)
+
 #include "vax_defs.h"
 #include "sim_video.h"
 
@@ -826,3 +828,5 @@ switch (mode) {
         break;
     }            
 }
+
+#endif /* !VAX_620 */
diff --git a/VAX/vax_vc.c b/VAX/vax_vc.c
index 8bc721a0..8e45e4de 100644
--- a/VAX/vax_vc.c
+++ b/VAX/vax_vc.c
@@ -31,6 +31,8 @@
    11-Jun-2013  MB      First version
 */
 
+#if !defined(VAX_620)
+
 #include "vax_defs.h"
 #include "sim_video.h"
 #include "vax_2681.h"
@@ -897,3 +899,5 @@ char *vc_description (DEVICE *dptr)
 {
 return "VCB01 Monochrome Graphics Adapter";
 }
+
+#endif /* !VAX_620 */
diff --git a/VAX/vax_vs.c b/VAX/vax_vs.c
index 234b2344..a8a55d71 100644
--- a/VAX/vax_vs.c
+++ b/VAX/vax_vs.c
@@ -29,6 +29,8 @@
    11-Jun-2013  MB      First version
 */
 
+#if !defined(VAX_620)
+
 #include "vax_defs.h"
 #include "sim_video.h"
 
@@ -223,3 +225,5 @@ if (vs_state == VSXXX_IDLE) {
         vs_sendupd ();
     }
 }
+
+#endif /* !VAX_620 */