diff --git a/PDP11/pdp11_stddev.c b/PDP11/pdp11_stddev.c
index 2f92121d..cff7a51e 100644
--- a/PDP11/pdp11_stddev.c
+++ b/PDP11/pdp11_stddev.c
@@ -95,6 +95,7 @@ t_stat tto_wr (int32 data, int32 PA, int32 access);
 t_stat tto_svc (UNIT *uptr);
 t_stat tto_reset (DEVICE *dptr);
 t_stat tty_set_mode (UNIT *uptr, int32 val, CONST char *cptr, void *desc);
+t_stat tty_set_parity (UNIT *uptr, int32 val, CONST char *cptr, void *desc);
 t_stat clk_rd (int32 *data, int32 PA, int32 access);
 t_stat clk_wr (int32 data, int32 PA, int32 access);
 t_stat clk_svc (UNIT *uptr);
@@ -115,7 +116,7 @@ DIB tti_dib = {
     1, IVCL (TTI), VEC_TTI, { NULL }
     };
 
-UNIT tti_unit = { UDATA (&tti_svc, UNIT_IDLE, 0), TMLN_SPD_9600_BPS };
+UNIT tti_unit = { UDATA (&tti_svc, UNIT_IDLE|TT_MODE_7P, 0), TMLN_SPD_9600_BPS };
 
 REG tti_reg[] = {
     { HRDATAD (BUF,       tti_unit.buf,          8, "last data item processed") },
@@ -130,10 +131,16 @@ REG tti_reg[] = {
     };
 
 MTAB tti_mod[] = {
-    { TT_MODE, TT_MODE_UC, "UC", "UC", &tty_set_mode },
-    { TT_MODE, TT_MODE_7B, "7b", "7B", &tty_set_mode },
-    { TT_MODE, TT_MODE_8B, "8b", "8B", &tty_set_mode },
-    { TT_MODE, TT_MODE_7P, "7b", NULL, NULL },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_KSR,   NULL, "KSR",   &tty_set_mode,   NULL, NULL, "KSR teletype mode" },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_KSR,   NULL, "KSR",   &tty_set_mode,   NULL, NULL, "Upper Case mode" },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_7B,    NULL, "7B",    &tty_set_mode,   NULL, NULL, "7 bit mode" },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_8B,    NULL, "8B",    &tty_set_mode,   NULL, NULL, "8 bit mode" },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_7P,    NULL, "7P",    &tty_set_mode,   NULL, NULL, "7 bit mode - non printing suppressed" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_SPACE,  NULL, "SPACE", &tty_set_parity, NULL, NULL, "Space Parity" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_MARK,   NULL, "MARK",  &tty_set_parity, NULL, NULL, "Mark Parity" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_EVEN,   NULL, "EVEN",  &tty_set_parity, NULL, NULL, "Even Parity" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_ODD,    NULL, "ODD",   &tty_set_parity, NULL, NULL, "Odd Parity" },
+    { MTAB_XTD|MTAB_VDV, 0, "MODE", NULL, NULL, &sim_tt_show_modepar, NULL, "Mode and Parity" },
     { MTAB_XTD|MTAB_VDV, 0, "ADDRESS", NULL,
       NULL, &show_addr, NULL },
     { MTAB_XTD|MTAB_VDV, 0, "VECTOR", NULL,
@@ -190,10 +197,16 @@ REG tto_reg[] = {
     };
 
 MTAB tto_mod[] = {
-    { TT_MODE, TT_MODE_UC, "UC", "UC", &tty_set_mode },
-    { TT_MODE, TT_MODE_7B, "7b", "7B", &tty_set_mode },
-    { TT_MODE, TT_MODE_8B, "8b", "8B", &tty_set_mode },
-    { TT_MODE, TT_MODE_7P, "7p", "7P", &tty_set_mode },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_KSR,   NULL, "KSR",   &tty_set_mode,   NULL, NULL, "KSR teletype mode" },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_UC,    NULL, "UC",    &tty_set_mode,   NULL, NULL, "Upper Case mode" },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_7B,    NULL, "7B",    &tty_set_mode,   NULL, NULL, "7 bit mode" },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_8B,    NULL, "8B",    &tty_set_mode,   NULL, NULL, "8 bit mode" },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_7P,    NULL, "7P",    &tty_set_mode,   NULL, NULL, "7 bit mode - non printing suppressed" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_SPACE,  NULL, "SPACE", &tty_set_parity, NULL, NULL, "Space Parity" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_MARK,   NULL, "MARK",  &tty_set_parity, NULL, NULL, "Mark Parity" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_EVEN,   NULL, "EVEN",  &tty_set_parity, NULL, NULL, "Even Parity" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_ODD,    NULL, "ODD",   &tty_set_parity, NULL, NULL, "Odd Parity" },
+    { MTAB_XTD|MTAB_VDV, 0, "MODE", NULL, NULL, &sim_tt_show_modepar, NULL, "Mode and Parity" },
     { MTAB_XTD|MTAB_VDV, 0, "ADDRESS", NULL,
       NULL, &show_addr, NULL },
     { MTAB_XTD|MTAB_VDV, 0, "VECTOR", NULL,
@@ -456,8 +469,17 @@ return SCPE_OK;
 
 t_stat tty_set_mode (UNIT *uptr, int32 val, CONST char *cptr, void *desc)
 {
-tti_unit.flags = (tti_unit.flags & ~TT_MODE) | val;
-tto_unit.flags = (tto_unit.flags & ~TT_MODE) | val;
+sim_tt_set_mode (&tti_unit, val, cptr, desc);
+sim_tt_set_mode (&tto_unit, val, cptr, desc);
+return SCPE_OK;
+}
+
+t_stat tty_set_parity (UNIT *uptr, int32 val, CONST char *cptr, void *desc)
+{
+sim_tt_set_parity (&tti_unit, val, cptr, desc);
+sim_tt_set_parity (&tto_unit, val, cptr, desc);
+tti_unit.flags = (tti_unit.flags & ~TT_PAR) | val;
+tto_unit.flags = (tto_unit.flags & ~TT_PAR) | val;
 return SCPE_OK;
 }
 
diff --git a/PDP8/pdp8_tt.c b/PDP8/pdp8_tt.c
index 2a13dc8e..0b3a03ae 100644
--- a/PDP8/pdp8_tt.c
+++ b/PDP8/pdp8_tt.c
@@ -55,6 +55,7 @@ t_stat tto_svc (UNIT *uptr);
 t_stat tti_reset (DEVICE *dptr);
 t_stat tto_reset (DEVICE *dptr);
 t_stat tty_set_mode (UNIT *uptr, int32 val, CONST char *cptr, void *desc);
+t_stat tty_set_parity (UNIT *uptr, int32 val, CONST char *cptr, void *desc);
 const char *tti_description (DEVICE *dptr);
 const char *tto_description (DEVICE *dptr);
 
@@ -81,10 +82,15 @@ REG tti_reg[] = {
     };
 
 MTAB tti_mod[] = {
-    { TT_MODE, TT_MODE_KSR, "KSR", "KSR", &tty_set_mode },
-    { TT_MODE, TT_MODE_7B,  "7b",  "7B",  &tty_set_mode },
-    { TT_MODE, TT_MODE_8B,  "8b",  "8B",  &tty_set_mode },
-    { TT_MODE, TT_MODE_7P,  "7b",  NULL,  NULL },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_KSR,   NULL, "KSR",   &tty_set_mode,   NULL, NULL, "KSR teletype mode" },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_7B,    NULL, "7B",    &tty_set_mode,   NULL, NULL, "7 bit mode" },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_8B,    NULL, "8B",    &tty_set_mode,   NULL, NULL, "8 bit mode" },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_7P,    NULL, "7P",    &tty_set_mode,   NULL, NULL, "7 bit mode - non printing suppressed" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_SPACE,  NULL, "SPACE", &tty_set_parity, NULL, NULL, "Space Parity" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_MARK,   NULL, "MARK",  &tty_set_parity, NULL, NULL, "Mark Parity" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_EVEN,   NULL, "EVEN",  &tty_set_parity, NULL, NULL, "Even Parity" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_ODD,    NULL, "ODD",   &tty_set_parity, NULL, NULL, "Odd Parity" },
+    { MTAB_XTD|MTAB_VDV, 0, "MODE", NULL, NULL, &sim_tt_show_modepar, NULL, "Mode and Parity" },
     { MTAB_XTD|MTAB_VDV, 0, "DEVNO", NULL, NULL, &show_dev, NULL },
     { 0 }
     };
@@ -123,10 +129,15 @@ REG tto_reg[] = {
     };
 
 MTAB tto_mod[] = {
-    { TT_MODE, TT_MODE_KSR, "KSR", "KSR", &tty_set_mode },
-    { TT_MODE, TT_MODE_7B,  "7b",  "7B",  &tty_set_mode },
-    { TT_MODE, TT_MODE_8B,  "8b",  "8B",  &tty_set_mode },
-    { TT_MODE, TT_MODE_7P,  "7p",  "7P",  &tty_set_mode },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_KSR,   NULL, "KSR",   &tty_set_mode,   NULL, NULL, "KSR teletype mode" },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_7B,    NULL, "7B",    &tty_set_mode,   NULL, NULL, "7 bit mode" },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_8B,    NULL, "8B",    &tty_set_mode,   NULL, NULL, "8 bit mode" },
+    { MTAB_XTD|MTAB_VDV, TT_MODE_7P,    NULL, "7P",    &tty_set_mode,   NULL, NULL, "7 bit mode - non printing suppressed" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_SPACE,  NULL, "SPACE", &tty_set_parity, NULL, NULL, "Space Parity" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_MARK,   NULL, "MARK",  &tty_set_parity, NULL, NULL, "Mark Parity" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_EVEN,   NULL, "EVEN",  &tty_set_parity, NULL, NULL, "Even Parity" },
+    { MTAB_XTD|MTAB_VDV, TT_PAR_ODD,    NULL, "ODD",   &tty_set_parity, NULL, NULL, "Odd Parity" },
+    { MTAB_XTD|MTAB_VDV, 0, "MODE", NULL, NULL, &sim_tt_show_modepar, NULL, "Mode and Parity" },
     { MTAB_XTD|MTAB_VDV, 0, "DEVNO", NULL, NULL, &show_dev },
     { 0 }
     };
@@ -285,8 +296,17 @@ return SCPE_OK;
 
 t_stat tty_set_mode (UNIT *uptr, int32 val, CONST char *cptr, void *desc)
 {
-tti_unit.flags = (tti_unit.flags & ~TT_MODE) | val;
-tto_unit.flags = (tto_unit.flags & ~TT_MODE) | val;
+sim_tt_set_mode (&tti_unit, val, cptr, desc);
+sim_tt_set_mode (&tto_unit, val, cptr, desc);
+return SCPE_OK;
+}
+
+t_stat tty_set_parity (UNIT *uptr, int32 val, CONST char *cptr, void *desc)
+{
+sim_tt_set_parity (&tti_unit, val, cptr, desc);
+sim_tt_set_parity (&tto_unit, val, cptr, desc);
+tti_unit.flags = (tti_unit.flags & ~TT_PAR) | val;
+tto_unit.flags = (tto_unit.flags & ~TT_PAR) | val;
 return SCPE_OK;
 }
 
diff --git a/sim_console.c b/sim_console.c
index 8e256a8b..069eac0e 100644
--- a/sim_console.c
+++ b/sim_console.c
@@ -2950,14 +2950,14 @@ uint32 md = mode & TTUF_M_MODE;
 
 if (md != TTUF_MODE_8B) {
     uint32 par_mode = (mode >> TTUF_W_MODE) & TTUF_M_PAR;
-    static int32 nibble_even_parity = 0x699600;   /* bit array indicating the even parity for each index (offset by 8) */
+    static int32 nibble_even_parity = 0x699600;     /* bit array indicating the even parity for each index (offset by 8) */
 
     c = c & 0177;
     if (md == TTUF_MODE_UC) {
         if (islower (c))
             c = toupper (c);
         if (mode & TTUF_KSR)
-            c = c | 0200;
+            c = c | 0200;                           /* Force MARK parity */
         }
     switch (par_mode) {
         case TTUF_PAR_EVEN:
@@ -2971,7 +2971,8 @@ if (md != TTUF_MODE_8B) {
             break;
         }
     }
-else c = c & 0377;
+else
+    c = c & 0377;
 return c;
 }
 
@@ -3051,6 +3052,43 @@ fprintf (st, (any? "\n": "no tabs set\n"));
 return SCPE_OK;
 }
 
+t_stat sim_tt_set_mode (UNIT *uptr, int32 val, CONST char *cptr, void *desc)
+{
+uint32 par_mode = (TT_GET_MODE (uptr->flags) >> TTUF_W_MODE) & TTUF_M_PAR;
+
+uptr->flags = uptr->flags & ~((TTUF_M_MODE << TTUF_V_MODE) | (TTUF_M_PAR << TTUF_V_PAR) | TTUF_KSR);
+uptr->flags |= val;
+if (val != TT_MODE_8B)
+    uptr->flags |= (par_mode << TTUF_V_PAR);
+return SCPE_OK;
+}
+
+t_stat sim_tt_set_parity (UNIT *uptr, int32 val, CONST char *cptr, void *desc)
+{
+uptr->flags = uptr->flags & ~(TTUF_M_MODE | TTUF_M_PAR);
+uptr->flags |= TT_MODE_7B | val;
+return SCPE_OK;
+}
+
+t_stat sim_tt_show_modepar (FILE *st, UNIT *uptr, int32 val, CONST void *desc)
+{
+uint32 md = (TT_GET_MODE (uptr->flags) & TTUF_M_MODE);
+static const char *modes[] = {"7b", "8b", "UC", "7p"};
+uint32 par_mode = (TT_GET_MODE (uptr->flags) >> TTUF_W_MODE) & TTUF_M_PAR;
+static const char *parity[] = {"SPACE", "MARK", "EVEN", "ODD"};
+
+if ((md == TTUF_MODE_UC) && (par_mode == TTUF_PAR_MARK))
+    fprintf (st, "KSR (UC, MARK parity)");
+else
+    fprintf (st, "%s", modes[md]);
+if ((md != TTUF_MODE_8B) && 
+    ((md != TTUF_MODE_UC) || (par_mode != TTUF_PAR_MARK))) {
+    if (par_mode != 0)
+        fprintf (st, ", %s parity", parity[par_mode]);
+    }
+return SCPE_OK;
+}
+
 
 #if defined(SIM_ASYNCH_IO) && defined(SIM_ASYNCH_MUX)
 extern pthread_mutex_t     sim_tmxr_poll_lock;
diff --git a/sim_console.h b/sim_console.h
index ae0ab86a..aa0c5949 100644
--- a/sim_console.h
+++ b/sim_console.h
@@ -60,7 +60,7 @@ extern "C" {
 #define  TT_MODE_8B     (TTUF_MODE_8B << TTUF_V_MODE)
 #define  TT_MODE_UC     (TTUF_MODE_UC << TTUF_V_MODE)
 #define  TT_MODE_7P     (TTUF_MODE_7P << TTUF_V_MODE)
-#define  TT_MODE_KSR    (TT_MODE_UC)
+#define  TT_MODE_KSR    (TT_MODE_UC|TT_PAR_MARK)
 /* 7 bit modes allow for an 8th bit parity mode */
 #define TT_PAR          (TTUF_M_PAR << TTUF_V_PAR)
 #define  TT_PAR_SPACE   (TTUF_PAR_SPACE << TTUF_V_PAR)
@@ -124,6 +124,9 @@ t_stat sim_ttclose (void);
 t_bool sim_ttisatty (void);
 int32 sim_tt_inpcvt (int32 c, uint32 mode);
 int32 sim_tt_outcvt (int32 c, uint32 mode);
+t_stat sim_tt_set_mode (UNIT *uptr, int32 val, CONST char *cptr, void *desc);
+t_stat sim_tt_set_parity (UNIT *uptr, int32 val, CONST char *cptr, void *desc);
+t_stat sim_tt_show_modepar (FILE *st, UNIT *uptr, int32 val, CONST void *desc);
 t_stat sim_tt_settabs (UNIT *uptr, int32 val, CONST char *cptr, void *desc);
 t_stat sim_tt_showtabs (FILE *st, UNIT *uptr, int32 val, CONST void *desc);
 t_bool sim_is_remote_console_master_line (void *lp);