From 685ca317a31cc37c21dcbecb177708874a9c29b9 Mon Sep 17 00:00:00 2001
From: "J. David Bryan" <jdbryan@acm.org>
Date: Tue, 19 Jan 2021 19:23:33 -0800
Subject: [PATCH] SCP: HP Only SCP and additional 3.11.2 JDB SCP Extensions

---
 Makefile.mak    |   7 +-
 makefile        |  13 +-
 scp.c           | 109 ++++++++++------
 scp.h           |  13 +-
 sim_defs.h      |  10 +-
 sim_extension.c | 110 +++++++++++++---
 sim_extension.h |  35 ++++--
 sim_rev.h       |  70 ++++++++++-
 sim_shmem.c     |  20 ++-
 sim_sock.c      |  31 ++---
 sim_sock.h      |   8 +-
 sim_tmxr.c      | 328 +++++++++++++++++++++++++++++++++++-------------
 sim_tmxr.h      |   4 +-
 13 files changed, 565 insertions(+), 193 deletions(-)

diff --git a/Makefile.mak b/Makefile.mak
index 147ae464..d1d1e79f 100644
--- a/Makefile.mak
+++ b/Makefile.mak
@@ -45,16 +45,17 @@ HP2100 = $(HP2100D)/hp2100_baci.c $(HP2100D)/hp2100_cpu.c $(HP2100D)/hp2100_cpu_
 	$(HP2100D)/hp2100_mt.c $(HP2100D)/hp2100_mux.c $(HP2100D)/hp2100_pif.c \
 	$(HP2100D)/hp2100_pt.c $(HP2100D)/hp2100_sys.c $(HP2100D)/hp2100_tbg.c \
 	$(HP2100D)/hp2100_tty.c
-HP2100_OPT = /DHAVE_INT64 /I$(HP2100D)
+HP2100_OPT = /D USE_VM_INIT /DHAVE_INT64 /I$(HP2100D)
 
 HP3000D = $(SCPD)\HP3000
 HP3000 = $(HP3000D)/hp_disclib.c $(HP3000D)/hp_tapelib.c $(HP3000D)/hp3000_atc.c \
 	$(HP3000D)/hp3000_clk.c $(HP3000D)/hp3000_cpu.c $(HP3000D)/hp3000_cpu_base.c \
-	$(HP3000D)/hp3000_cpu_fp.c $(HP3000D)/hp3000_cpu_cis.c $(HP3000D)/hp3000_ds.c \
+	$(HP3000D)/hp3000_cpu_fp.c $(HP3000D)/hp3000_cpu_eis.c \
+	$(HP3000D)/hp3000_cpu_cis.c $(HP3000D)/hp3000_ds.c \
 	$(HP3000D)/hp3000_iop.c $(HP3000D)/hp3000_lp.c $(HP3000D)/hp3000_mem.c \
 	$(HP3000D)/hp3000_mpx.c $(HP3000D)/hp3000_ms.c $(HP3000D)/hp3000_scmb.c \
 	$(HP3000D)/hp3000_sel.c $(HP3000D)/hp3000_sys.c
-HP3000_OPT = /I$(HP3000D)
+HP3000_OPT = /D USE_VM_INIT /I$(HP3000D)
 
 
 clean :
diff --git a/makefile b/makefile
index 00f5927a..38ae1cd7 100644
--- a/makefile
+++ b/makefile
@@ -321,8 +321,8 @@ ifeq ($(WIN32),)  #*nix Environments (&& cygwin)
       ifeq (,$(NOASYNCH))
         OS_CCDEFS += -DSIM_ASYNCH_IO 
       endif
-#      OS_LDFLAGS += -lpthread
-#      $(info using libpthread: $(call find_lib,pthread) $(call find_include,pthread))
+      OS_LDFLAGS += -lpthread
+      $(info using libpthread: $(call find_lib,pthread) $(call find_include,pthread))
     endif
   endif
   ifneq (,$(call find_include,semaphore))
@@ -534,7 +534,7 @@ endif
 
 # Shut up annoying clang default warnings.
 
-ifeq ($(GCC),clang)
+ifeq ($(findstring clang,$(COMPILER_NAME)),clang)
   OS_CCDEFS += -Wno-parentheses -Wno-bitwise-op-parentheses -Wno-dangling-else
 endif
 
@@ -568,16 +568,17 @@ HP2100 = ${HP2100D}/hp2100_baci.c ${HP2100D}/hp2100_cpu.c ${HP2100D}/hp2100_cpu_
 	${HP2100D}/hp2100_mt.c ${HP2100D}/hp2100_mux.c ${HP2100D}/hp2100_pif.c \
 	${HP2100D}/hp2100_pt.c ${HP2100D}/hp2100_sys.c ${HP2100D}/hp2100_tbg.c \
 	${HP2100D}/hp2100_tty.c
-HP2100_OPT = -D HAVE_INT64 -I ${HP2100D}
+HP2100_OPT = -D USE_VM_INIT -D HAVE_INT64 -I ${HP2100D}
 
 HP3000D = HP3000
 HP3000 = ${HP3000D}/hp_disclib.c ${HP3000D}/hp_tapelib.c ${HP3000D}/hp3000_atc.c \
 	${HP3000D}/hp3000_clk.c ${HP3000D}/hp3000_cpu.c ${HP3000D}/hp3000_cpu_base.c \
-	${HP3000D}/hp3000_cpu_fp.c ${HP3000D}/hp3000_cpu_cis.c ${HP3000D}/hp3000_ds.c \
+	${HP3000D}/hp3000_cpu_fp.c ${HP3000D}/hp3000_cpu_eis.c \
+	${HP3000D}/hp3000_cpu_cis.c ${HP3000D}/hp3000_ds.c \
 	${HP3000D}/hp3000_iop.c ${HP3000D}/hp3000_lp.c ${HP3000D}/hp3000_mem.c \
 	${HP3000D}/hp3000_mpx.c ${HP3000D}/hp3000_ms.c ${HP3000D}/hp3000_scmb.c \
 	${HP3000D}/hp3000_sel.c ${HP3000D}/hp3000_sys.c
-HP3000_OPT = -I ${HP3000D}
+HP3000_OPT = -D USE_VM_INIT -I ${HP3000D}
 
 
 #
diff --git a/scp.c b/scp.c
index b7cef257..d4e4b8a6 100644
--- a/scp.c
+++ b/scp.c
@@ -23,6 +23,10 @@
    used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from Robert M Supnik.
 
+   23-Oct-20    JDB     Added tmxr_post_logs calls to flush and close log files
+   04-Jun-20    JDB     Call of "sim_vm_init" is now conditional on USE_VM_INIT
+   28-May-20    RMS     Flush stdout after prompting (Mark Pizzolato)
+   23-Mar-20    RMS     Added SET <dev|unit> APPEND command
    13-Feb-20    RMS     Spelled out CONTINUE in command table (Dave Bryan)
    09-Jan-20    JDB     Added "sim_vm_unit_name" extension hook
    26-Oct-19    RMS     Removed commented out MTAB_VAL code
@@ -58,7 +62,7 @@
                         Modified ex_reg and dep_reg to pass VM-specific register flags
    08-May-12    RMS     Fixed memory leaks in save/restore (Peter Schorn)
    20-Mar-12    MP      Fixes to "SHOW <x> SHOW" commands
-   06-Jan-12    JDB     Fixed "SHOW DEVICE" with only one enabled unit (Dave Bryan)  
+   06-Jan-12    JDB     Fixed "SHOW DEVICE" with only one enabled unit (Dave Bryan)
    13-Jan-11    MP      Added "SHOW SHOW" and "SHOW <dev> SHOW" commands
    05-Jan-11    RMS     Fixed bug in deposit stride for numeric input (John Dundas)
    23-Dec-10    RMS     Clarified some help messages (Mark Pizzolato)
@@ -220,6 +224,7 @@
 /* Macros and data structures */
 
 #include "sim_defs.h"
+#include "sim_tmxr.h"
 #include <signal.h>
 #include <ctype.h>
 
@@ -278,10 +283,8 @@
 #define GET_RADIX(val,dft) \
     val = sim_get_radix (NULL, sim_switches, dft);
 
-/* The per-simulator init routine is a weak global that defaults to NULL
-   The other per-simulator pointers can be overrriden by the init routine */
+/* The per-simulator pointers can be overrriden by a VM init routine */
 
-void (*sim_vm_init) (void);
 char* (*sim_vm_read) (char *ptr, int32 size, FILE *stream) = NULL;
 void (*sim_vm_post) (t_bool from_scp) = NULL;
 CTAB *sim_vm_cmd = NULL;
@@ -297,6 +300,7 @@ t_bool (*sim_vm_is_subroutine_call) (t_addr **ret_addrs) = NULL;
 t_stat set_dev_radix (DEVICE *dptr, UNIT *uptr, int32 flag, char *cptr);
 t_stat set_dev_enbdis (DEVICE *dptr, UNIT *uptr, int32 flag, char *cptr);
 t_stat set_dev_debug (DEVICE *dptr, UNIT *uptr, int32 flag, char *cptr);
+t_stat set_dev_unit_append (DEVICE *dptr, UNIT *uptr, int32 flag, char *cptr);
 t_stat set_unit_enbdis (DEVICE *dptr, UNIT *uptr, int32 flag, char *cptr);
 t_stat ssh_break (FILE *st, char *cptr, int32 flg);
 t_stat show_cmd_fi (FILE *ofile, int32 flag, char *cptr);
@@ -531,7 +535,7 @@ static CTAB cmd_table[] = {
     { "RUN", &run_cmd, RU_RUN,
       "ru{n} {new PC}           reset and start simulation\n" },
     { "GO", &run_cmd, RU_GO,
-      "go {new PC}              start simulation\n" }, 
+      "go {new PC}              start simulation\n" },
     { "STEP", &run_cmd, RU_STEP,
       "s{tep} {n}               simulate n instructions\n" },
     { "CONTINUE", &run_cmd, RU_CONT,
@@ -574,23 +578,25 @@ static CTAB cmd_table[] = {
       "set <dev> DISABLED       disable device\n"
       "set <dev> DEBUG{=arg}    set device debug flags\n"
       "set <dev> NODEBUG={arg}  clear device debug flags\n"
+      "set <dev> APPEND         set first unit's position for appending\n"
       "set <dev> arg{,arg...}   set device parameters (see show modifiers)\n"
       "set <unit> ENABLED       enable unit\n"
       "set <unit> DISABLED      disable unit\n"
+      "set <unit> APPEND        set unit's position for appending\n"
       "set <unit> arg{,arg...}  set unit parameters (see show modifiers)\n"
       },
     { "SHOW", &show_cmd, 0,
       "sh{ow} br{eak} <list>    show breakpoints\n"
       "sh{ow} con{figuration}   show configuration\n"
       "sh{ow} cons{ole} {arg}   show console options\n"
-      "sh{ow} dev{ices}         show devices\n"  
-      "sh{ow} m{odifiers}       show modifiers for all devices\n" 
-      "sh{ow} s{how}            show SHOW commands for all devices\n" 
-      "sh{ow} n{ames}           show logical names\n" 
-      "sh{ow} q{ueue}           show event queue\n"  
+      "sh{ow} dev{ices}         show devices\n"
+      "sh{ow} m{odifiers}       show modifiers for all devices\n"
+      "sh{ow} s{how}            show SHOW commands for all devices\n"
+      "sh{ow} n{ames}           show logical names\n"
+      "sh{ow} q{ueue}           show event queue\n"
       "sh{ow} ti{me}            show simulated time\n"
-      "sh{ow} th{rottle}        show simulation rate\n" 
-      "sh{ow} ve{rsion}         show simulator version\n" 
+      "sh{ow} th{rottle}        show simulation rate\n"
+      "sh{ow} ve{rsion}         show simulator version\n"
       "sh{ow} <dev> RADIX       show device display radix\n"
       "sh{ow} <dev> DEBUG       show device debug flags\n"
       "sh{ow} <dev> MODIFIERS   show device modifiers\n"
@@ -636,6 +642,7 @@ static C1TAB set_dev_tab[] = {
     { "HEX", &set_dev_radix, 16 },
     { "ENABLED", &set_dev_enbdis, 1 },
     { "DISABLED", &set_dev_enbdis, 0 },
+    { "APPEND", &set_dev_unit_append, 0 },
     { "DEBUG", &set_dev_debug, 1 },
     { "NODEBUG", &set_dev_debug, 0 },
     { NULL, NULL, 0 }
@@ -644,6 +651,7 @@ static C1TAB set_dev_tab[] = {
 static C1TAB set_unit_tab[] = {
     { "ENABLED", &set_unit_enbdis, 1 },
     { "DISABLED", &set_unit_enbdis, 0 },
+    { "APPEND", &set_dev_unit_append, 0 },
     { NULL, NULL, 0 }
     };
 
@@ -717,7 +725,7 @@ for (i = 1; i < argc; i++) {                            /* loop thru args */
             return 0;
             }
         if (*cbuf)                                      /* concat args */
-            strcat (cbuf, " "); 
+            strcat (cbuf, " ");
         strcat (cbuf, argv[i]);
         lookswitch = FALSE;                             /* no more switches */
         }
@@ -726,9 +734,10 @@ sim_quiet = sim_switches & SWMASK ('Q');                /* -q means quiet */
 
 sim_init_sock ();                                       /* init socket capabilities */
 
-if (sim_vm_init != NULL)                                /* call once only */
-    (*sim_vm_init)();
-sim_finit ();                                           /* init fio package */
+#if defined (USE_VM_INIT)
+(*sim_vm_init)();                                       /* call once only */
+#endif
+sim_finit();                                            /* init fio package */
 stop_cpu = 0;
 sim_interval = 0;
 sim_time = sim_rtime = 0;
@@ -804,7 +813,8 @@ while (stat != SCPE_EXIT) {                             /* in case exit */
         (*sim_vm_post) (TRUE);
     }                                                   /* end while */
 
-detach_all (0, TRUE);                                   /* close files */
+detach_all (0, TRUE);                                   /* close device files */
+tmxr_post_logs (TRUE);                                  /* close all mux log files */
 sim_set_deboff (0, NULL);                               /* close debug */
 sim_set_logoff (0, NULL);                               /* close log */
 sim_set_notelnet (0, NULL);                             /* close Telnet */
@@ -913,7 +923,7 @@ return SCPE_OK;
 
    Note that SCPE_STEP ("Step expired") is considered a note and not an error
    and so does not abort command execution when using -E.
-   
+
    Inputs:
         flag    =   caller and nesting level indicator
         fcptr   =   filename and optional arguments, space-separated
@@ -1081,10 +1091,10 @@ return;
 }
 
 /* ASSERT command.
-   
+
    The ASSERT command tests the value of a device register or memory location.
    The syntax is:
-   
+
      ASSERT {<dev>} <reg/addr>{<logical-op><value>}<conditional-op><value>
 
    If <dev> is not specified, CPU is assumed.  If a register is specified, the
@@ -1352,6 +1362,25 @@ else {
 return SCPE_OK;
 }
 
+/* Set unit position to end for appending */
+
+t_stat set_dev_unit_append (DEVICE *dptr, UNIT *uptr, int32 flag, char *cptr)
+{
+if (cptr)
+    return SCPE_ARG;
+if (uptr == NULL)
+    return SCPE_NOFNC;
+if (((uptr->flags & UNIT_SEQ) == 0) ||                  /* must be sequential, */
+    ((uptr->flags & UNIT_ROABLE) != 0) ||               /* not RO settable */
+    ((uptr->flags & UNIT_MUSTBUF) != 0))                /* not buffered */
+    return SCPE_NOFNC;
+if ((uptr->flags & UNIT_ATT) == 0)                      /* must be attached */
+    return SCPE_UNATT;
+if (sim_fseek (uptr->fileref, 0, SEEK_END) != 0)        /* seek to end */
+   return SCPE_IOERR;
+uptr->pos = (t_addr) sim_ftell (uptr->fileref);         /* set at EOF */
+return SCPE_OK;
+}
 /* Set device debug enabled/disabled routine */
 
 t_stat set_dev_debug (DEVICE *dptr, UNIT *uptr, int32 flag, char *cptr)
@@ -1452,7 +1481,7 @@ while (*cptr != 0) {                                    /* do all mods */
         *cvptr++ = 0;
     for (mptr = dptr->modifiers; mptr && (mptr->mask != 0); mptr++) {
         if (((mptr->mask & MTAB_XTD)?                   /* right level? */
-            (mptr->mask & lvl): (MTAB_VUN & lvl)) && 
+            (mptr->mask & lvl): (MTAB_VUN & lvl)) &&
             ((mptr->disp && mptr->pstring &&            /* named disp? */
             (MATCH_CMD (gbuf, mptr->pstring) == 0)))) {
             if (cvptr && !(mptr->mask & MTAB_SHP))
@@ -1544,7 +1573,7 @@ if (uptr->flags & UNIT_ATT) {
     }
 else if (uptr->flags & UNIT_ATTABLE)
     fprintf (st, ", not attached");
-show_all_mods (st, dptr, uptr, MTAB_VUN);               /* show unit mods */ 
+show_all_mods (st, dptr, uptr, MTAB_VUN);               /* show unit mods */
 fprintf (st, "\n");
 return SCPE_OK;
 }
@@ -1723,7 +1752,7 @@ DEVICE *dptr;
 
 if (cptr && (*cptr != 0))                               /* now eol? */
     return SCPE_2MARG;
-for (i = 0; (dptr = sim_devices[i]) != NULL; i++) 
+for (i = 0; (dptr = sim_devices[i]) != NULL; i++)
     show_dev_modifiers (st, dptr, NULL, flag, cptr);
 return SCPE_OK;
 }
@@ -1777,7 +1806,7 @@ if (dptr->modifiers == NULL)
     return SCPE_OK;
 for (mptr = dptr->modifiers; mptr->mask != 0; mptr++) {
     if (mptr->pstring && ((mptr->mask & MTAB_XTD)?
-        ((mptr->mask & flag) && !(mptr->mask & MTAB_NMO)): 
+        ((mptr->mask & flag) && !(mptr->mask & MTAB_NMO)):
         ((MTAB_VUN & flag) && ((uptr->flags & mptr->mask) == mptr->match)))) {
         fputs (", ", st);
         show_one_mod (st, dptr, uptr, mptr, NULL, 0);
@@ -1815,7 +1844,7 @@ DEVICE *dptr;
 
 if (cptr && (*cptr != 0))                               /* now eol? */
     return SCPE_2MARG;
-for (i = 0; (dptr = sim_devices[i]) != NULL; i++) 
+for (i = 0; (dptr = sim_devices[i]) != NULL; i++)
     show_dev_show_commands (st, dptr, NULL, flag, cptr);
 return SCPE_OK;
 }
@@ -1875,7 +1904,7 @@ t_stat r;
 t_addr lo, hi, max;
 int32 cnt;
 
-if (sim_brk_types == 0) 
+if (sim_brk_types == 0)
     return SCPE_NOFNC;
 if (dptr == NULL)                                       /* sanity checks */
     return SCPE_IERR;
@@ -1913,7 +1942,7 @@ while (*cptr) {
             sim_brk_showall (st, sim_switches);
         else return SCPE_ARG;
         }
-    else {      
+    else {
         for ( ; lo <= hi; lo = lo + 1) {
             r = ssh_break_one (st, flg, lo, cnt, aptr);
             if (r != SCPE_OK)
@@ -2541,7 +2570,7 @@ sim_ref_type = REF_NONE;                                /* use no references */
 READ_S (buf);                                           /* [V2.5+] read version */
 v35 = v32 = FALSE;
 if (strcmp (buf, save_vercur) == 0)                     /* version 3.5? */
-    v35 = v32 = TRUE;  
+    v35 = v32 = TRUE;
 else if (strcmp (buf, save_ver32) == 0)                 /* version 3.2? */
     v32 = TRUE;
 else if (strcmp (buf, save_ver30) != 0) {               /* version 3.0? */
@@ -2583,7 +2612,7 @@ for ( ;; ) {                                            /* device loop */
         }
     READ_S (buf);                                       /* [V3.0+] logical name */
     deassign_device (dptr);                             /* delete old name */
-    if ((buf[0] != 0) && 
+    if ((buf[0] != 0) &&
         ((r = assign_device (dptr, buf)) != SCPE_OK))
         return r;
     READ_I (flg);                                       /* [V2.10+] ctlr flags */
@@ -2842,6 +2871,7 @@ for (i = 1; (dptr = sim_devices[i]) != NULL; i++) {     /* flush attached files
             fflush (uptr->fileref);
         }
     }
+tmxr_post_logs (FALSE);                                 /* flush all mux log files */
 #if defined (VMS)
 sim_printf ("\n");
 #endif
@@ -2879,7 +2909,7 @@ t_stat r = 0;
 t_addr k;
 t_value pcval;
 
-fputc ('\n', st);                                       /* skip a line */    
+fputc ('\n', st);                                       /* skip a line */
 
 if (v >= SCPE_BASE)                                     /* SCP error? */
     fputs (sim_error_text (v), st);                     /* print it from the SCP list */
@@ -3012,7 +3042,7 @@ for (gptr = gbuf, reason = SCPE_OK;
     tdptr = sim_dfdev;                                  /* working dptr */
     if (strncmp (gptr, "STATE", strlen ("STATE")) == 0) {
         tptr = gptr + strlen ("STATE");
-        if (*tptr && (*tptr++ != ',')) 
+        if (*tptr && (*tptr++ != ','))
             return SCPE_ARG;
         if ((lowr = sim_dfdev->registers) == NULL)
             return SCPE_NXREG;
@@ -3071,7 +3101,7 @@ return reason;
    exdep_addr_loop      examine/deposit range of addresses
 */
 
-t_stat exdep_reg_loop (FILE *ofile, SCHTAB *schptr, int32 flag, char *cptr, 
+t_stat exdep_reg_loop (FILE *ofile, SCHTAB *schptr, int32 flag, char *cptr,
     REG *lowr, REG *highr, uint32 lows, uint32 highs)
 {
 t_stat reason;
@@ -3317,13 +3347,13 @@ if ((rptr->depth > 1) && (rptr->flags & REG_UNIT)) {
 #if defined (USE_INT64)
     if (sz <= sizeof (uint32))
         *((uint32 *) uptr) = (*((uint32 *) uptr) &
-        ~(((uint32) mask) << rptr->offset)) | 
+        ~(((uint32) mask) << rptr->offset)) |
         (((uint32) val) << rptr->offset);
     else *((t_uint64 *) uptr) = (*((t_uint64 *) uptr)
         & ~(mask << rptr->offset)) | (val << rptr->offset);
 #else
     *((uint32 *) uptr) = (*((uint32 *) uptr) &
-        ~(((uint32) mask) << rptr->offset)) | 
+        ~(((uint32) mask) << rptr->offset)) |
         (((uint32) val) << rptr->offset);
 #endif
     }
@@ -3505,7 +3535,7 @@ for (i = 0, j = addr; i < count; i++, j = j + dptr->aincr) {
     else {
         if (!(uptr->flags & UNIT_ATT))
             return SCPE_UNATT;
-        if (uptr->flags & UNIT_RAW) 
+        if (uptr->flags & UNIT_RAW)
             return SCPE_NOFNC;
         if ((uptr->flags & UNIT_FIX) && (j >= uptr->capac))
             return SCPE_NXM;
@@ -3513,7 +3543,7 @@ for (i = 0, j = addr; i < count; i++, j = j + dptr->aincr) {
         loc = j / dptr->aincr;
         if (uptr->flags & UNIT_BUF) {
             SZ_STORE (sz, sim_eval[i], uptr->filebuf, loc);
-            if (loc >= uptr->hwmark) 
+            if (loc >= uptr->hwmark)
                 uptr->hwmark = (uint32) loc + 1;
             }
         else {
@@ -3636,13 +3666,16 @@ if (prompt) {                                           /* interactive? */
         }
     else {
         printf ("%s", prompt);                          /* display prompt */
+        fflush (stdout);
         cptr = fgets (cptr, size, stream);              /* get cmd line */
         }
     }
 else cptr = fgets (cptr, size, stream);                 /* get cmd line */
 #else
-if (prompt)                                             /* interactive? */
+if (prompt) {                                           /* interactive? */
     printf ("%s", prompt);                              /* display prompt */
+    fflush (stdout);
+    }
 cptr = fgets (cptr, size, stream);                      /* get cmd line */
 #endif
 
@@ -4241,7 +4274,7 @@ while (*cptr) {                                         /* loop through modifier
         cptr = get_glyph_nc (cptr + 1, gbuf, 0);
         sim_ofile = sim_fopen (gbuf, "a");              /* open for append */
         if (sim_ofile == NULL) {                        /* open failed? */
-            *st = SCPE_OPENERR;                        
+            *st = SCPE_OPENERR;
             return NULL;
             }
         sim_opt_out |= CMD_OPT_OF;                      /* got output file */
diff --git a/scp.h b/scp.h
index 58d84cbd..50bb567b 100644
--- a/scp.h
+++ b/scp.h
@@ -1,6 +1,6 @@
 /* scp.h: simulator control program headers
 
-   Copyright (c) 1993-2019, Robert M Supnik
+   Copyright (c) 1993-2020, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -23,6 +23,7 @@
    be used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from Robert M Supnik.
 
+   04-Jun-20    JDB     Declaration of "sim_vm_init" is now conditional on USE_VM_INIT
    08-Dec-19    JDB     Added "sim_vm_unit_name" extension hook
    09-Oct-19    JDB     Added "detach_all" global declaration
    19-Jul-19    JDB     Added "sim_get_radix" extension hook
@@ -228,10 +229,14 @@ extern t_stat fprint_sym (FILE *ofile, t_addr addr, t_value *val,
 extern t_stat parse_sym (char *cptr, t_addr addr, UNIT *uptr, t_value *val,
     int32 sw);
 
-/* The per-simulator init routine is a weak global that defaults to NULL
-   The other per-simulator pointers can be overrriden by the init routine */
+/* The per-simulator init routine is declared (and called) only if the
+   compilation defines the USE_VM_INIT symbol.  The other per-simulator pointers
+   can be overrriden by the init routine or by the CPU reset routine that is
+   called during simulator startup, whichever is preferred. */
 
-extern void (*sim_vm_init) (void);
+#if defined (USE_VM_INIT)
+extern void(*sim_vm_init) (void);
+#endif
 extern char* (*sim_vm_read) (char *ptr, int32 size, FILE *stream);
 extern void (*sim_vm_post) (t_bool from_scp);
 extern CTAB *sim_vm_cmd;
diff --git a/sim_defs.h b/sim_defs.h
index aa5159e8..a1c288bc 100644
--- a/sim_defs.h
+++ b/sim_defs.h
@@ -116,6 +116,9 @@
 #include <stddef.h>
 #include <stdlib.h>
 #include <stdio.h>
+#if defined(_MSC_VER) && (_MSC_VER < 1900)
+#define snprintf _snprintf      /* poor man's snprintf which will work most of the time but has different return value */
+#endif
 #include <stdarg.h>
 #include <string.h>
 #include <errno.h>
@@ -542,6 +545,9 @@ struct sim_debtab {
 #define FLDATA(nm,loc,pos) #nm, &(loc), 2, 1, (pos), 1
 #define GRDATA(nm,loc,rdx,wd,pos) #nm, &(loc), (rdx), (wd), (pos), 1
 #define BRDATA(nm,loc,rdx,wd,dep) #nm, (loc), (rdx), (wd), 0, (dep)
+#define VBRDATA(nm,loc,rdx,wd,dep) #nm, (loc), (rdx), (wd), 0, (dep)
+#define SAVEDATA(nm,loc) \
+    #nm, &(loc), 8, 8, 0, sizeof(loc), REG_HRO
 #define URDATA(nm,loc,rdx,wd,off,dep,fl) \
     #nm, &(loc), (rdx), (wd), (off), (dep), ((fl) | REG_UNIT)
 #else
@@ -551,6 +557,9 @@ struct sim_debtab {
 #define FLDATA(nm,loc,pos) "nm", &(loc), 2, 1, (pos), 1
 #define GRDATA(nm,loc,rdx,wd,pos) "nm", &(loc), (rdx), (wd), (pos), 1
 #define BRDATA(nm,loc,rdx,wd,dep) "nm", (loc), (rdx), (wd), 0, (dep)
+#define VBRDATA(nm,loc,rdx,wd,dep) "nm", (loc), (rdx), (wd), 0, (dep)
+#define SAVEDATA(nm,loc) \
+    "nm", &(loc), 8, 8, 0, sizeof(loc), REG_HRO
 #define URDATA(nm,loc,rdx,wd,off,dep,fl) \
     "nm", &(loc), (rdx), (wd), (off), (dep), ((fl) | REG_UNIT)
 #endif
@@ -585,7 +594,6 @@ typedef struct sim_debtab DEBTAB;
    when compiling for SIMH 3.x.
 */
 
-
 #if defined (__STDC__) || defined (_WIN32)
 #define ORDATAD(nm,loc,wd,desc) #nm, &(loc), 8, (wd), 0, 1
 #define DRDATAD(nm,loc,wd,desc) #nm, &(loc), 10, (wd), 0, 1
diff --git a/sim_extension.c b/sim_extension.c
index ba469f60..ab4fc0f8 100644
--- a/sim_extension.c
+++ b/sim_extension.c
@@ -23,6 +23,11 @@
    used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from the author.
 
+   21-Oct-20    JDB     A NULL poll pointer is now valid for MUX attach and detach
+   20-Oct-20    JDB     Added FLUSH command to post file contents to disc
+   25-Aug-20    JDB     Call of "vm_sim_vm_init" is now conditional on USE_VM_INIT
+   03-Aug-20    JDB     IF now retains remainder of breakpoint command list
+   06-Jul-20    JDB     Silence spurious compiler warning in "ex_if_cmd"
    14-Feb-20    JDB     First release version
    18-Mar-19    JDB     Created
 
@@ -274,14 +279,11 @@ static void ex_initialize (void);
 void (*sim_vm_init) (void) = ex_initialize;     /* use our one-time initializer */
 
 
-/* Hooks provided by us for the back end virtual machine */
+/* Hooks provided by us for use by the back end virtual machine */
 
-CTAB *vm_sim_vm_cmd = NULL;
-
-void (*vm_sim_vm_init) (void);
-
-UNIT *vm_console_input_unit;                    /* console input unit pointer */
-UNIT *vm_console_output_unit;                   /* console output unit pointer */
+CTAB *vm_sim_vm_cmd          = NULL;            /* VM command extension table */
+UNIT *vm_console_input_unit  = NULL;            /* console input unit pointer */
+UNIT *vm_console_output_unit = NULL;            /* console output unit pointer */
 
 
 /* Pointer to the VM handler for unit names */
@@ -519,6 +521,7 @@ static t_stat ex_run_cmd        (int32 flag, char *cptr);
 static t_stat ex_do_cmd         (int32 flag, char *cptr);
 static t_stat ex_if_cmd         (int32 flag, char *cptr);
 static t_stat ex_delete_cmd     (int32 flag, char *cptr);
+static t_stat ex_flush_cmd      (int32 flag, char *cptr);
 static t_stat ex_restricted_cmd (int32 flag, char *cptr);
 static t_stat ex_set_cmd        (int32 flag, char *cptr);
 static t_stat ex_show_cmd       (int32 flag, char *cptr);
@@ -605,6 +608,7 @@ static CTAB ex_cmds [] = {
 
     { "IF",       ex_if_cmd,          0,          "if <cond> <cmd>;...      execute commands if condition TRUE\n"   },
     { "DELETE",   ex_delete_cmd,      0,          "del{ete} <file>          delete a file\n"                        },
+    { "FLUSH",    ex_flush_cmd,       0,          "f{lush}                  flush all open files to disc\n"         },
 
     { "GOTO",     ex_restricted_cmd,  EX_GOTO,    "goto <label>             transfer control to the labeled line\n" },
     { "CALL",     ex_restricted_cmd,  EX_CALL,    "call <label> {<par>...}  call the labeled subroutine\n"          },
@@ -739,8 +743,10 @@ sim_vm_cmd    = ex_cmds;                                /* set up the extension
 sub_args      = ex_substitute_args;                     /*   and argument substituter */
 sim_get_radix = ex_get_radix;                           /*     and EX/DEP/SET radix configuration */
 
+#if defined (USE_VM_INIT)
 if (vm_sim_vm_init != NULL)                             /* if the VM has a one-time initializer */
     vm_sim_vm_init ();                                  /*   then call it now */
+#endif
 
 vm_unit_name_handler = sim_vm_unit_name;                /* save the unit name hook in case the VM set it */
 sim_vm_unit_name = breakpoint_name;                     /*   and substitute our own */
@@ -955,7 +961,8 @@ return;
    If a device is referenced, the poll unit specified by the "pptr" parameter is
    attached instead of the referenced unit.  This is because a device reference
    passes a pointer to unit 0 (i.e., ATTACH MUX and ATTACH MUX0 both set "uptr"
-   to point at unit 0).
+   to point at unit 0).  If the poll unit is not defined, then the device attach
+   is rejected.
 
    An attempt to attach the poll unit directly via a unit reference will be
    rejected by the "ex_tmxr_attach_line" routine because the unit does not
@@ -967,9 +974,12 @@ t_stat ex_tmxr_attach_unit (TMXR *mp, UNIT *pptr, UNIT *uptr, char *cptr)
 t_stat status;
 
 if (sim_ref_type == REF_DEVICE)                         /* if this is a device reference */
-    uptr = pptr;                                        /*   then substitute the poll unit */
+    if (pptr == NULL)                                   /*   then if the poll unit is not defined */
+        return SCPE_NOATT;                              /*     then report that the attach failed */
+    else                                                /*   otherwise */
+        uptr = pptr;                                    /*     substitute the poll unit */
 
-if (mp == NULL || pptr == NULL || uptr == NULL)         /* if the descriptor, poll, or unit pointer is null */
+if (mp == NULL || uptr == NULL)                         /* if the descriptor or unit pointer is null */
     status = SCPE_IERR;                                 /*   then report an internal error */
 
 else if (sim_ref_type != REF_UNIT                       /* otherwise if this is a device or null reference */
@@ -1000,7 +1010,8 @@ return status;                                          /* return the status of
    If a device is referenced, the poll unit specified by the "pptr" parameter is
    detached instead of the referenced unit.  This is because a device reference
    passes a pointer to unit 0 (i.e., DETACH MUX and DETACH MUX0 both set "uptr"
-   to point at unit 0).
+   to point at unit 0).  If the poll unit is not defined, then the device detach
+   is rejected.
 
    An attempt to detach the poll unit directly via a unit reference will be
    rejected by the "ex_tmxr_detach_line" routine because the unit does not
@@ -1012,9 +1023,12 @@ t_stat ex_tmxr_detach_unit (TMXR *mp, UNIT *pptr, UNIT *uptr)
 t_stat status;
 
 if (sim_ref_type == REF_DEVICE)                         /* if this is a device reference */
-    uptr = pptr;                                        /*   then substitute the poll unit */
+    if (pptr == NULL)                                   /*   then if the poll unit is not defined */
+        return SCPE_NOATT;                              /*     then report that the attach failed */
+    else                                                /*   otherwise */
+        uptr = pptr;                                    /*     substitute the poll unit */
 
-if (mp == NULL || pptr == NULL || uptr == NULL)         /* if the descriptor, poll, or unit pointer is null */
+if (mp == NULL || uptr == NULL)                         /* if the descriptor or unit pointer is null */
     status = SCPE_IERR;                                 /*   then report an internal error */
 
 else if (sim_ref_type != REF_UNIT                       /* otherwise if this is a device or null reference */
@@ -1324,6 +1338,7 @@ return TRUE;                                            /* the mux is free, as t
 }
 
 
+
 /* Hooked terminal multiplexer replacement extension routines */
 
 
@@ -2762,6 +2777,7 @@ static const char allowed_cmds [] = " "                         /* the list of u
     "DO "       "ECHO "     "ASSERT "   "HELP "
 
     "REPLY "    "NOREPLY "  "IF "       "DELETE "   "ABORT "    /*   extended commands */
+    "FLUSH "
 
     "POWER ";                                                   /*   simulator-specific commands */
 
@@ -2819,6 +2835,7 @@ return status;                                          /* return the search res
      CALL    -- call the labeled subroutine
      RETURN  -- return control from a subroutine
      ABORT   -- abort nested command files
+     FLUSH   -- flush all buffered files
 
    The RUN and GO commands are enhanced to add an UNTIL option that sets a
    temporary breakpoint, and all of the simulated execution commands are
@@ -3521,6 +3538,17 @@ return status;                                          /* return the command st
        results if the buffers overlap ("cptr" points into the command buffer, so
        "sim_brk_act" would be copying a command within the buffer to the start
        of the same buffer).
+
+    2. An IF command may appear as an action within a breakpoint command or
+       another IF command.  To support this, any actions of a true IF command
+       are prefixed to any remaining breakpoint or IF actions by concatenating
+       the two sets of actions in a temporary buffer.  Were this not done, the
+       remaining actions would be lost when "sim_brk_act" is pointed at the new
+       IF actions.
+
+    3. Any unexecuted actions must be copied to a separate buffer before
+       prefixing, as they will reside in the same buffer that will hold the
+       prefix if they are the result of a prior IF command.
 */
 
 typedef enum {                                  /* test operators */
@@ -3539,8 +3567,9 @@ static t_stat ex_if_cmd (int32 flag, char *cptr)
 {
 static char tempbuf [CBUFSIZE];
 struct stat statbuf;
-int         result, condition;
-char        abuf [CBUFSIZE], bbuf [CBUFSIZE];
+int         result, condition = 0;                      /* silence spurious gcc-9.2.0 compiler warning */
+char        abuf [CBUFSIZE], bbuf [CBUFSIZE], *tptr;
+int32       bufsize;
 t_bool      upshift, invert;
 TEST_OP     test;
 LOGICAL_OP  logical = Assign;
@@ -3675,7 +3704,26 @@ do {                                                    /* loop until all condit
 while (not_done);                                       /* continue to process logical comparisons until done */
 
 if (condition)                                          /* if the comparison is true */
-    sim_brk_act = strcpy (tempbuf, cptr);               /*   then copy the action string and execute the commands */
+    if (sim_brk_act == NULL)                            /*   then if no unexecuted actions remain */
+        sim_brk_act = strcpy (tempbuf, cptr);           /*     then copy our action string to a buffer */
+
+    else {                                              /* otherwise */
+        strcpy (abuf, sim_brk_act);                     /*   save the unexecuted actions in a separate buffer */
+
+        tptr = tempbuf;                                 /* point at the action buffer */
+        bufsize = CBUFSIZE;                             /*   and initialize the remaining size */
+
+        copy_string (&tptr, &bufsize, cptr, 0);         /* copy the current actions as a prefix */
+
+        if (bufsize > 1) {                              /* if space remains */
+            *tptr++ = ';';                              /*   then append the action separator */
+            bufsize = bufsize - 1;                      /*     and account for the space */
+
+            copy_string (&tptr, &bufsize, abuf, 0);     /* copy the unexecuted actions */
+            }
+
+        sim_brk_act = tempbuf;                          /* point at the concatenated action list */
+        }
 
 return SCPE_OK;                                         /* either way, the command succeeded */
 }
@@ -3705,6 +3753,36 @@ else                                                    /* otherwise */
 }
 
 
+/* Execute the FLUSH command.
+
+   This command processing routine adds a new FLUSH command to flush all
+   buffered files to disc.  The routine processes commands of the form:
+
+     FLUSH
+
+   For files that are open, the command flushes the console and debug log files,
+   the files attached to all of the units of all devices, and log files
+   associated with terminal multiplexer lines.
+
+   The command provides a way to flush buffered file contents to disc without
+   having to stop and restart simulated execution.  As such, it is useful when
+   the console is in concurrent mode.  In nonconcurrent mode, stopping the
+   simulator to enter the FLUSH command will automatically flush all open files,
+   so the command is redundant in that case.
+*/
+
+static t_stat ex_flush_cmd (int32 flag, char *cptr)
+{
+if (*cptr != '\0')                                      /* if something follows */
+    return SCPE_2MARG;                                  /*   then report extraneous characters */
+
+else {                                                  /* otherwise */
+    fflush (NULL);                                      /*   flush all open files */
+    return SCPE_OK;
+    }
+}
+
+
 /* Execute a restricted command.
 
    This command processing routine is called when the user attempts to execute
diff --git a/sim_extension.h b/sim_extension.h
index 0b3e5fa3..ed9a45e8 100644
--- a/sim_extension.h
+++ b/sim_extension.h
@@ -23,6 +23,7 @@
    used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from the author.
 
+   25-Aug-20    JDB     Declaration of "vm_sim_vm_init" is now conditional on USE_VM_INIT
    31-Dec-19    JDB     First release version
    18-Mar-19    JDB     Created file
 */
@@ -91,19 +92,27 @@ t_stat ex_sim_putchar_s (int32 c);
 t_stat ex_sim_poll_kbd  (void);
 uint32 ex_sim_brk_test  (t_addr location, uint32 type);
 
-t_stat ex_tmxr_attach_unit   (TMXR *mp, UNIT *pptr, UNIT *uptr, char *cptr);
-t_stat ex_tmxr_detach_unit   (TMXR *mp, UNIT *pptr, UNIT *uptr);
-t_stat ex_tmxr_detach_line   (TMXR *mp, UNIT *uptr);
-t_stat ex_tmxr_control_line  (TMLN *lp, TMCKT control);
-TMCKT  ex_tmxr_line_status   (TMLN *lp);
-int32  ex_tmxr_poll_conn     (TMXR *mp);
-t_bool ex_tmxr_line_free     (TMLN *lp);
-t_bool ex_tmxr_mux_free      (TMXR *mp);
+t_stat ex_tmxr_attach_unit  (TMXR *mp, UNIT *pptr, UNIT *uptr, char *cptr);
+t_stat ex_tmxr_detach_unit  (TMXR *mp, UNIT *pptr, UNIT *uptr);
+t_stat ex_tmxr_detach_line  (TMXR *mp, UNIT *uptr);
+t_stat ex_tmxr_control_line (TMLN *lp, TMCKT control);
+TMCKT  ex_tmxr_line_status  (TMLN *lp);
+int32  ex_tmxr_poll_conn    (TMXR *mp);
+t_bool ex_tmxr_line_free    (TMLN *lp);
+t_bool ex_tmxr_mux_free     (TMXR *mp);
 
 
-extern void   (*vm_sim_vm_init) (void);
-extern CTAB   *vm_sim_vm_cmd;
-extern t_stat vm_sim_instr      (void);
+/* The per-simulator init routine is declared (and called) only if the
+   compilation defines the USE_VM_INIT symbol.  The other per-simulator pointers
+   can be overrriden by the init routine or by the CPU reset routine that is
+   called during simulator startup, whichever is preferred.
+*/
 
-extern UNIT *vm_console_input_unit;             /* console input unit pointer */
-extern UNIT *vm_console_output_unit;            /* console output unit pointer */
+#if defined (USE_VM_INIT)
+extern void (*vm_sim_vm_init) (void);
+#endif
+
+extern t_stat vm_sim_instr (void);
+extern CTAB   *vm_sim_vm_cmd;                   /* VM-specific command table pointer */
+extern UNIT   *vm_console_input_unit;           /* console input unit pointer */
+extern UNIT   *vm_console_output_unit;          /* console output unit pointer */
diff --git a/sim_rev.h b/sim_rev.h
index bf1c7f5c..9da2df46 100644
--- a/sim_rev.h
+++ b/sim_rev.h
@@ -29,7 +29,7 @@
 
 #define SIM_MAJOR       3
 #define SIM_MINOR       11
-#define SIM_PATCH       0
+#define SIM_PATCH       2
 #define SIM_DELTA       0
 
 /* V3.11 revision history
@@ -37,14 +37,82 @@
    V3.11 incorporates SCP additions and extensions by Dave Bryan to support his
    HP simulators.
 
+patch   date            module(s) and fix(es)
+
+  2     tbd             scp.h
+                        - changed sim_vm_init to build time option (Dave Bryan)
+
+                        scp.c
+                        - changed sim_vm_init to build time option (Dave Bryan)
+                        - flush stdout after prompt (Mark Pizzolato)
+
+                        pdp10_tu.c
+                        - fixed bad macro (Mark Pizzolata)
+
+                        pdp11_cpumod.c
+                        - fixed KDJ11E programmable rate select (Paul Koning)
+
+                        pdp11_stddev.c
+                        - added KSR option for TTI/TTO
+
+                        pdp18b_dr15.c
+                        - zero out shared section on initial allocate (Dave Bryan)
+
+                        s3_sys.c
+                        - fixed bldaddr length (Mark Pizzolatto)
+
+                        vax_cpu.c
+                        - added idle test for VMS 5.0/5.1 (Mark Pizzolato)
+
+  1     31-Mar-2020     scp.c and sim_tmxr_c
+                        - new extensions to support HP simulators
+                        - added SET <dev|unit> APPEND command
+
+                        sim_ether library
+                        - imported latest V4 revision
+
+                        Alpha
+                        - fixed DMAPEN register definition
+
+                        Interdata
+                        - fixed DP xTIME register definitions
+
+                        NOVA
+                        - fixed processing of tape UNLOAD
+
+                        PDP-1
+                        - generalized PTR ASCII mode handling of end-of-line and end-of-tape
+
+                        PDP-10
+                        - fixed processing of tape UNLOAD
+
+                        PDP-11
+                        - fixed PT INT definition
+                        - disabled VH11 (temporarily) because of multiline race condition
+                        - fixed processing of tape UNLOAD in TM, TU
+
+                        PDP-8
+                        - fixed processing of tape UNLOAD
+
+                        Sigma
+                        - fixed incorrect 550 interrupt register array declaration
+                        - fixed processing of tape UNLOAD
+
+                        VAX
+                        - disabled VH11 (temporarily) because of multiline race condition
+
 patch   date            module(s) and fix(es)
 
   0     01-Dec-2019     scp.c and supporting libraries
                         - new features and extensions to support the HP simulators
+                        - lengthened CONT to CONTNIUE for V4.x compatibility
 
                         sim_sock.c
                         - latest bug fixes from V4.x
 
+                        PDP-11
+                        - fixed race condition in DZ11 (Mark Pizzolato)
+
                         VAX
                         - added hook for unpredictable indexed immediate in .aw flows
                         - revamped Qbus memory simulation to behave as a Qbus peripheral
diff --git a/sim_shmem.c b/sim_shmem.c
index 8ab1b3f6..216f9667 100644
--- a/sim_shmem.c
+++ b/sim_shmem.c
@@ -1,6 +1,6 @@
 /* sim_shmem.c: simulator shared memory library
 
-   Copyright (c) 2015-2016, Robert M Supnik
+   Copyright (c) 2015-2020, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -23,6 +23,9 @@
    used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from Robert M Supnik.
 
+   25-Aug-20    JDB     Added __FreeBSD__ define to Unix implementation guard
+   01-Jul-20    JDB     Added __CYGWIN__ define to Unix implementation guard
+
    This library includes:
 
    sim_shmem_open           create or attach to a shared memory region
@@ -119,7 +122,7 @@ t_bool sim_shmem_atomic_cas (int32 *ptr, int32 oldv, int32 newv)
 return (InterlockedCompareExchange ((LONG volatile *) ptr, newv, oldv) == oldv);
 }
 
-#elif defined (__linux__) || defined (__APPLE__)
+#elif defined (__linux__) || defined (__APPLE__) || defined (__CYGWIN__) || defined (__FreeBSD__)
 #include <unistd.h>
 #include <sys/stat.h>
 #include <fcntl.h>
@@ -134,7 +137,7 @@ struct SHMEM {
 
 t_stat sim_shmem_open (const char *name, size_t size, SHMEM **shmem, void **addr)
 {
-#ifdef HAVE_SHM_OPEN
+#if defined (HAVE_SHM_OPEN) && defined (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
 *shmem = (SHMEM *)calloc (1, sizeof(**shmem));
 mode_t orig_mask;
 
@@ -191,25 +194,30 @@ if ((*shmem)->shm_base == MAP_FAILED) {
 *addr = (*shmem)->shm_base;
 return SCPE_OK;
 #else
+*shmem = NULL;
 return SCPE_NOFNC;
 #endif
 }
 
 void sim_shmem_close (SHMEM *shmem)
 {
+#if defined (HAVE_SHM_OPEN)
 if (shmem == NULL)
     return;
 if (shmem->shm_base != MAP_FAILED)
     munmap (shmem->shm_base, shmem->shm_size);
-if (shmem->shm_fd != -1)
+if (shmem->shm_fd != -1) {
+    shm_unlink (shmem->shm_name);
     close (shmem->shm_fd);
+    }
 free (shmem->shm_name);
 free (shmem);
+#endif
 }
 
 int32 sim_shmem_atomic_add (int32 *p, int32 v)
 {
-#if defined (HAVE_GCC_SYNC_BUILTINS)
+#if defined (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
 return __sync_add_and_fetch((int *) p, v);
 #else
 return *p + v;
@@ -218,7 +226,7 @@ return *p + v;
 
 t_bool sim_shmem_atomic_cas (int32 *ptr, int32 oldv, int32 newv)
 {
-#if defined (HAVE_GCC_SYNC_BUILTINS)
+#if defined (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
 return __sync_bool_compare_and_swap (ptr, oldv, newv);
 #else
 if (*ptr == oldv) {
diff --git a/sim_sock.c b/sim_sock.c
index a1388183..6f357cc3 100644
--- a/sim_sock.c
+++ b/sim_sock.c
@@ -1,6 +1,6 @@
 /* sim_sock.c: OS-dependent socket routines
 
-   Copyright (c) 2001-2019, Robert M Supnik
+   Copyright (c) 2001-2010, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -23,7 +23,6 @@
    used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from Robert M Supnik.
 
-   22-Nov-19    MP      Latest 4.X changes
    15-Oct-12    MP      Added definitions needed to detect possible tcp 
                         connect failures
    25-Sep-12    MP      Reworked for RFC3493 interfaces supporting IPv6 and IPv4
@@ -263,6 +262,7 @@ if (service) {
     char *c;
 
     port = strtoul(service, &c, 10);
+    port = htons((unsigned short)port);
     if ((port == 0) || (*c != '\0')) {
         switch (hints->ai_socktype)
             {
@@ -432,6 +432,10 @@ return 0;
 #if !defined(IPV6_V6ONLY)           /* Older XP environments may not define IPV6_V6ONLY */
 #define IPV6_V6ONLY           27    /* Treat wildcard bind as AF_INET6-only. */
 #endif
+#if defined(TEST_INFO_STUBS)
+#undef IPV6_V6ONLY
+#undef AF_INET6
+#endif
 /* Dynamic DLL load variables */
 #ifdef _WIN32
 static HINSTANCE hLib = 0;                      /* handle to DLL */
@@ -684,7 +688,7 @@ return 0;
         port    =       pointer to buffer for IP port (may be NULL), 0 = none
         localport
                 =       pointer to buffer for local IP port (may be NULL), 0 = none
-        result  =       status (SCPE_OK on complete success or SCPE_ARG if 
+        result  =       status (0 on complete success or -1 if 
                         parsing can't happen due to bad syntax, a value is 
                         out of range, a result can't fit into a result buffer, 
                         a service name doesn't exist, or a validation name 
@@ -739,6 +743,12 @@ load_ws2 ();
 #if defined (SIGPIPE)
 signal (SIGPIPE, SIG_IGN);                              /* no pipe signals */
 #endif
+#if defined(TEST_INFO_STUBS)
+/* force use of stubs */
+p_getaddrinfo = (getaddrinfo_func)s_getaddrinfo;
+p_getnameinfo = (getnameinfo_func)s_getnameinfo;
+p_freeaddrinfo = (freeaddrinfo_func)s_freeaddrinfo;
+#endif
 }
 
 void sim_cleanup_sock (void)
@@ -918,7 +928,7 @@ if (sta == SOCKET_ERROR)                                /* bind error? */
 if (!(opt_flags & SIM_SOCK_OPT_BLOCKING)) {
     sta = sim_setnonblock (newsock);                    /* set nonblocking */
     if (sta == SOCKET_ERROR)                            /* fcntl error? */
-        return sim_err_sock (newsock, "fcntl");
+        return sim_err_sock (newsock, "setnonblock");
     }
 sta = listen (newsock, 1);                              /* listen on socket */
 if (sta == SOCKET_ERROR)                                /* listen error? */
@@ -990,7 +1000,7 @@ if (!(opt_flags & SIM_SOCK_OPT_BLOCKING)) {
     sta = sim_setnonblock (newsock);                    /* set nonblocking */
     if (sta == SOCKET_ERROR) {                          /* fcntl error? */
         p_freeaddrinfo (result);
-        return sim_err_sock (newsock, "fcntl");
+        return sim_err_sock (newsock, "setnonblock");
         }
     }
 if ((!(opt_flags & SIM_SOCK_OPT_DATAGRAM)) && (opt_flags & SIM_SOCK_OPT_NODELAY)) {
@@ -1064,20 +1074,16 @@ if (newsock == INVALID_SOCKET) {                        /* error? */
     }
 if (connectaddr != NULL) {
     *connectaddr = (char *)calloc(1, NI_MAXHOST+1);
-#ifdef AF_INET6
     p_getnameinfo((struct sockaddr *)&clientname, size, *connectaddr, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
     if (0 == memcmp("::ffff:", *connectaddr, 7))        /* is this a IPv4-mapped IPv6 address? */
         memmove(*connectaddr, 7+*connectaddr,           /* prefer bare IPv4 address */
                 strlen(*connectaddr) - 7 + 1);          /* length to include terminating \0 */
-#else
-    strcpy(*connectaddr, inet_ntoa(((struct sockaddr_in *)&connectaddr)->s_addr));
-#endif
     }
 
 if (!(opt_flags & SIM_SOCK_OPT_BLOCKING)) {
     sta = sim_setnonblock (newsock);                    /* set nonblocking */
     if (sta == SOCKET_ERROR)                            /* fcntl error? */
-        return sim_err_sock (newsock, "fcntl");
+        return sim_err_sock (newsock, "setnonblock");
     }
 
 if ((opt_flags & SIM_SOCK_OPT_NODELAY)) {
@@ -1152,7 +1158,6 @@ size_t size = addrsize;
 #endif
 int ret = 0;
 
-#ifdef AF_INET6
 *hostnamebuf = '\0';
 *portnamebuf = '\0';
 ret = p_getnameinfo(addr, size, hostnamebuf, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
@@ -1161,10 +1166,6 @@ if (0 == memcmp("::ffff:", hostnamebuf, 7))        /* is this a IPv4-mapped IPv6
             strlen(hostnamebuf) + 7 - 1);          /* length to include terminating \0 */
 if (!ret)
     ret = p_getnameinfo(addr, size, NULL, 0, portnamebuf, NI_MAXSERV, NI_NUMERICSERV);
-#else
-strcpy(hostnamebuf, inet_ntoa(((struct sockaddr_in *)addr)->s_addr));
-sprintf(portnamebuf, "%d", (int)ntohs(((struct sockaddr_in *)addr)->s_port)));
-#endif
 return ret;
 }
 
diff --git a/sim_sock.h b/sim_sock.h
index 326720c7..f42e8f16 100644
--- a/sim_sock.h
+++ b/sim_sock.h
@@ -90,8 +90,10 @@ extern "C" {
 #endif
 #define WSAEACCES       EACCES
 #define WSAEINTR        EINTR
-#define INVALID_SOCKET  ((SOCKET)-1) 
-#define SOCKET_ERROR    -1
+#define INVALID_SOCKET  ((SOCKET)-1)
+#if !defined(SOCKET_ERROR)
+#define SOCKET_ERROR    (-1)
+#endif
 #endif
 
 #if defined (VMS)                                       /* VMS unique */
@@ -118,7 +120,7 @@ int sim_parse_addr_ex (const char *cptr, char *host, size_t hostlen, const char
 SOCKET sim_master_sock_ex (const char *hostport, int *parse_status, int opt_flags);
 #define sim_master_sock(hostport, parse_status) sim_master_sock_ex(hostport, parse_status, ((sim_switches & SWMASK ('U')) ? SIM_SOCK_OPT_REUSEADDR : 0))
 SOCKET sim_connect_sock_ex (const char *sourcehostport, const char *hostport, const char *default_host, const char *default_port, int opt_flags);
-#define sim_connect_sock(hostport, default_host, default_port) sim_connect_sock_ex(NULL, hostport, default_host, default_port, 0)
+#define sim_connect_sock(hostport, default_host, default_port) sim_connect_sock_ex(NULL, hostport, default_host, default_port, SIM_SOCK_OPT_BLOCKING)
 SOCKET sim_accept_conn_ex (SOCKET master, char **connectaddr, int opt_flags);
 #define sim_accept_conn(master, connectaddr) sim_accept_conn_ex(master, connectaddr, 0)
 int sim_check_conn (SOCKET sock, int rd);
diff --git a/sim_tmxr.c b/sim_tmxr.c
index 93d6d091..8d1c9188 100644
--- a/sim_tmxr.c
+++ b/sim_tmxr.c
@@ -1,6 +1,6 @@
 /* sim_tmxr.c: Telnet terminal multiplexor library
 
-   Copyright (c) 2001-2019, Robert M Supnik
+   Copyright (c) 2001-2020, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -26,6 +26,9 @@
    Based on the original DZ11 simulator by Thord Nilson, as updated by
    Arthur Krewat.
 
+   26-Oct-20    JDB     Line order now supports partial connection lists
+   23-Oct-20    JDB     Added tmxr_table and tmxr_post_logs
+                        tmxr_set_log now takes -N switch for new file
    19-Dec-19    JDB     Added tmxr_is_extended global hook
    19-Mar-19    JDB     Added tmxr_read, tmxr_write, tmxr_show, tmxr_close
                         global hooks and associated local hook routines;
@@ -79,16 +82,25 @@
    tmxr_dep     -       (null) deposit
    tmxr_msg     -       send message to socket
    tmxr_linemsg -       send message to line
-   tmxr_fconns  -       output connection status
-   tmxr_fstats  -       output connection statistics
+   tmxr_fconns  -       output line connection status
+   tmxr_fstats  -       output line connection statistics
+   tmxr_set_log -       open a log file for a terminal line
+   tmxr_set_nolog -     close a log file for a terminal line
+   tmxr_post_logs -     flush and optionally close all log files
+   tmxr_show_log -      output log file status
    tmxr_dscln   -       disconnect line (SET routine)
    tmxr_rqln    -       number of available characters for line
    tmxr_tqln    -       number of buffered characters for line
    tmxr_set_lnorder -   set line connection order
    tmxr_show_lnorder -  show line connection order
-   tmxr_init_line -     initialize the line data
-   tmxr_report_connection - report a line connection to the port
-   tmxr_disconnect_line - disconnect a line
+   tmxr_show_summ -     output the number of connections
+   tmxr_show_cstat -    output device connection status or statistics
+   tmxr_show_lines -    output the number of lines
+   tmxr_find_ldsc -     find a line descriptor
+   tmxr_send_buffered_data -    write the line data
+   tmxr_init_line -             initialize the line data
+   tmxr_report_connection -     report a line connection to the port
+   tmxr_disconnect_line -       disconnect a line
 
    All routines are OS-independent.
 */
@@ -139,6 +151,21 @@
 #define TNS_CRPAD       005                             /* CR padding */
 #define TNS_DO          006                             /* DO request pending rejection */
 
+/* Multiplexer-descriptor table.
+
+   Each device multiplexer declares a multiplexer descriptor (TMXR) structure to
+   identify the mux and its terminal lines.  The structure is local to the
+   device simulator, and nothing in the DEVICE structure points to it, so there
+   is no external way of accessing the line (TMLN) structures.  Access is needed
+   if the associated terminal line logs are to be flushed when a simulator stop
+   occurs and closed when the simulator exits.  This is provided by a global
+   table of TMXR structures that is filled in when line logs are opened.
+*/
+
+#define TABLE_COUNT     10                              /* the number of table entries provided */
+
+static TMXR *tmxr_table [TABLE_COUNT] = { NULL };       /* the table of multiplexer descriptors */
+
 void tmxr_rmvrc (TMLN *lp, int32 p);
 
 extern char sim_name[];
@@ -165,15 +192,22 @@ t_bool (*tmxr_is_extended) (TMLN *lp)               = NULL;
         line number activated, -1 if none
 
    If a connection order is defined for the descriptor, and the first value is
-   not -1 (indicating default order), then the order array is used to find an
-   open line.  Otherwise, a search is made of all lines in numerical sequence.
+   not < 0 to indicate the default order, then the order array is used to find
+   an open line.  Otherwise, a search is made of all lines in numerical
+   sequence.
+
+   If some valid lines are to be omitted from the connection order, a value < 0
+   will appear after the last allowed line value.  For example, specifying
+   connection order values of 1, 0, 2, and -1 will allow connections to lines 1,
+   0, and 2 in that order.  Additional connection attempts will fail with "All
+   connections busy," even though more lines are available in the device.
 */
 
 int32 tmxr_poll_conn (TMXR *mp)
 {
 SOCKET newsock;
 TMLN *lp;
-int32 *op;
+int32 *op, *fop;
 int32 i, j;
 char *ipaddr = NULL;
 
@@ -187,14 +221,20 @@ static char mantra[] = {
 
 newsock = sim_accept_conn (mp->master, &ipaddr);        /* poll connect */
 if (newsock != INVALID_SOCKET) {                        /* got a live one? */
-    op = mp->lnorder;                                   /* get line connection order list pointer */
+    fop = op = mp->lnorder;                             /* get line connection order list pointer */
     i = mp->lines;                                      /* play it safe in case lines == 0 */
 
-    for (j = 0; j < mp->lines; j++, i++) {              /* find next avail line */
-        if (op && (*op >= 0) && (*op < mp->lines))      /* order list present and valid? */
-            i = *op++;                                  /* get next line in list to try */
-        else                                            /* no list or not used or range error */
-            i = j;                                      /* get next sequential line */
+    for (j = 0; j < mp->lines; j++, i++) {              /* find the next available line */
+        if (fop == NULL || *fop < 0)                    /* if the first list entry is undefined or defaulted */
+            i = j;                                      /*   then use the next sequential line */
+
+        else if (*op >= 0 && *op < mp->lines)           /* otherwise if the line number is legal */
+            i = *op++;                                  /*   then use the next listed line */
+
+        else {                                          /* otherwise the list entry is invalid */
+            i = mp->lines;                              /*   so abandon the search now */
+            break;                                      /*     and report that no lines are free */
+            }
 
         lp = mp->ldsc + i;                              /* get pointer to line descriptor */
         if (lp->conn == 0)                              /* is the line available? */
@@ -422,9 +462,9 @@ for (i = 0; i < mp->lines; i++) {                       /* loop thru lines */
                     lp->tsta = TNS_SKIP;                /* IAC + other */
                     break;
                 case TN_GA: case TN_EL:                 /* IAC + other 2 byte types */
-                case TN_EC: case TN_AYT:                
+                case TN_EC: case TN_AYT:
                 case TN_AO: case TN_IP:
-                case TN_NOP: 
+                case TN_NOP:
                     lp->tsta = TNS_NORM;                /* ignore */
                     break;
                 case TN_SB:                             /* IAC + SB sub-opt negotiation */
@@ -811,12 +851,28 @@ if (lp->conn) {
 return SCPE_OK;
 }
 
-/* Enable logging for line */
+/* Enable logging for line.
+
+   This routine opens the log file whose name is specified by "cptr" for the
+   multiplexer line associated with "uptr" or, if NULL, for the line number
+   specified by "val".  "desc" contains a pointer to the multiplexer descriptor.
+
+   If opening is successful, the routine then adds the descriptor pointer to the
+   table of descriptors, which is used to flush and eventually close the log
+   files.
+
+
+   Implementation notes:
+
+    1. Table entries are not removed, so a NULL entry indicates both the end of
+       the active list and the first available space.
+*/
 
 t_stat tmxr_set_log (UNIT *uptr, int32 val, char *cptr, void *desc)
 {
 TMXR *mp = (TMXR *) desc;
 TMLN *lp;
+uint32 index;
 
 if (cptr == NULL)                                       /* no file name? */
     return SCPE_2FARG;
@@ -829,12 +885,29 @@ lp->txlogname = (char *) calloc (CBUFSIZE, sizeof (char)); /* alloc namebuf */
 if (lp->txlogname == NULL)                              /* can't? */
     return SCPE_MEM;
 strncpy (lp->txlogname, cptr, CBUFSIZE);                /* save file name */
-lp->txlog = fopen (cptr, "ab");                         /* open log */
+if (sim_switches & SWMASK ('N'))                        /* if a new log file is requested */
+    lp->txlog = fopen (cptr, "wb");                     /*   then open an empty file for writing */
+else                                                    /* otherwise */
+    lp->txlog = fopen (cptr, "ab");                     /*   open an existing file for appending */
 if (lp->txlog == NULL) {                                /* error? */
     free (lp->txlogname);                               /* free buffer */
     return SCPE_OPENERR;
     }
-return SCPE_OK;
+else {                                                  /* otherwise if the open succeeded */
+    for (index = 0; index < TABLE_COUNT; index++)       /* loop through the table entries */
+        if (tmxr_table [index] == mp)                   /* if the mux descriptor is already present */
+            break;                                      /*   then we're done */
+
+        else if (tmxr_table [index] == NULL) {          /* otherwise if the entry is empty */
+            tmxr_table [index] = mp;                    /*   then store the new descriptor */
+            break;                                      /*     and we're done */
+            }
+
+    if (index == TABLE_COUNT)                           /* if there are no empty entries */
+        return SCPE_IERR;                               /*   then report an internal error */
+    else                                                /* otherwise the descriptor was */
+        return SCPE_OK;                                 /*   either already present or added */
+    }
 }
 
 /* Disable logging for line */
@@ -858,6 +931,52 @@ if (lp->txlog) {                                        /* logging? */
 return SCPE_OK;
 }
 
+/* Flush and optionally close all log files.
+
+   This routine flushes or closes all active terminal multiplexer line logs,
+   depending on the value of the boolean parameter.  The routine uses the table
+   of multiplexer descriptors constructed by the "tmxr_set_log" routine to
+   identify the active lines.  The line structure array associated with each
+   descriptor is examined in sequence for active logs.  Each one that is found
+   is flushed to post the contents to disc and left open, or closed and marked
+   inactive, as directed by the supplied parameter.
+
+
+   Implementation notes:
+
+    1. The table is organized so that a NULL entry indicates that no additional
+       descriptors will be found.  That is, descriptors always appear at the
+       beginning of the table.
+*/
+
+void tmxr_post_logs (t_bool close_logs)
+{
+uint32 index;
+int32  line, line_count;
+TMXR   *mptr;
+TMLN   *lptr;
+
+for (index = 0; index < TABLE_COUNT; index++)           /* look through the descriptor list */
+    if (tmxr_table [index] == NULL)                     /*   until all entries */
+        break;                                          /*     have been seen */
+
+    else {                                              /* for each active entry */
+        mptr = tmxr_table [index];                      /*   get the entry */
+        lptr = mptr->ldsc;                              /*     and the line array */
+        line_count = mptr->lines;                       /*       and the number of lines */
+
+        for (line = 0; line < line_count; line++, lptr++)   /* for all lines in the array */
+            if (lptr->txlog != NULL)                        /*   if the current line's log is active */
+                if (close_logs)                             /*     then if closing is requested */
+                    tmxr_set_nolog (NULL, line, NULL,       /*        then close the log */
+                                    (void *) mptr);
+                else                                        /* otherwise */
+                    fflush (lptr->txlog);                   /*   flush the log and leave it open */
+        }
+
+return;
+}
+
 /* Show logging status for line */
 
 t_stat tmxr_show_log (FILE *st, UNIT *uptr, int32 val, void *desc)
@@ -880,7 +999,7 @@ return SCPE_OK;
    device indicated in the TMXR structure.  That is, the multiplexer lines may
    belong to a device other than the one attached to the socket (the HP 2100 MUX
    device is one example).  Therefore, we must look up the device from the unit
-   at each call, rather than depending on the DPTR stored in the TMXR.
+   at each call, rather than depending on the dptr stored in the TMXR.
 */
 
 TMLN *tmxr_find_ldsc (UNIT *uptr, int32 val, TMXR *mp)
@@ -898,110 +1017,146 @@ return mp->ldsc + val;                                  /* line descriptor */
 
 /* Set the line connection order.
 
-   Example command for eight-line multiplexer:
+   This validation routine is called to set the connection order for the
+   multiplexer whose TMXR pointer is passed in the "desc" parameter.  It parses
+   the line order list, specified by the "cptr" parameter, of commands such as:
 
-      SET <dev> LINEORDER=1;5;2-4;7
+      SET <dev> LINEORDER=4-7
+      SET <dev> LINEORDER=1;5;2-4;7;ALL
+      SET <dev> LINEORDER=ALL
 
-   Resulting connection order: 1,5,2,3,4,7,0,6.
+   Assuming an 8-channel multiplexer, the first form sets the connection order
+   to line numbers 4, 5, 6, and 7.  The remaining lines will not be connected; a
+   connection attempt will be refused with "All connections busy."  The second
+   form sets the connection order to line 1, 5, 2, 3, 4, 7, 0, and 6.  The
+   trailing "ALL" parameter causes any unspecified lines to be added to the
+   connection order in ascending value.  The third form sets the order to lines
+   0-7, which is the default order in the absence of a line connection order
+   array.
 
-   Parameters:
-    - uptr = (not used)
-    - val  = (not used)
-    - cptr = pointer to first character of range specification
-    - desc = pointer to multiplexer's TMXR structure
+   The range of accepted line numbers, including those implied by "ALL", can be
+   restricted by specifying a non-zero "val" parameter, with the upper 16 bits
+   specifying the maximum line number, and the lower 16 bits specifying the
+   minimum line number.  If a minimum is specified but a maximum is not (i.e.,
+   is zero), the maximum is the last line number defined by the multiplexer
+   descriptor.
 
-   On entry, cptr points to the value portion of the command string, which may
-   be either a semicolon-separated list of line ranges or the keyword ALL.
+   The "uptr" parameter is not used.
+
+   On entry, "cptr" points to the value portion of the command string, which may
+   be either a semicolon-separated list of line ranges or the keyword "ALL".  If
+   "ALL" is specified, it must be the last (or only) item in the list.
 
    If a line connection order array is not defined in the multiplexer
-   descriptor, the command is rejected.  If the specified range encompasses all
-   of the lines, the first value of the connection order array is set to -1 to
+   descriptor, or a line range string is not present, or the optional minimum
+   and maximum restrictions in the "val" parameter are not valid, the command is
+   rejected.  If the specified range encompasses all of the lines defined by the
+   multiplexer, the first value of the connection order array is set to -1 to
    indicate sequential connection order.  Otherwise, the line values in the
-   array are set to the order specified by the command string.  All values are
-   populated, first with those explicitly specified in the command string, and
-   then in ascending sequence with those not specified.
+   array are set to the order specified by the command string.  If fewer values
+   are supplied than there are lines supported by the device, and the final
+   parameter is not ALL, the remaining lines will be inaccessible and are
+   indicated by a -1 value after the last specified value.
 
    If an error occurs, the original line order is not disturbed.
 */
 
 t_stat tmxr_set_lnorder (UNIT *uptr, int32 val, char *cptr, void *desc)
 {
-TMXR *mp = (TMXR *) desc;
-char *tptr;
-t_addr low, high, max = (t_addr) mp->lines - 1;
-int32 *list;
+TMXR   *mp = (TMXR *) desc;
+char   *tptr;
+t_addr low, high, min, max;
+int32  *list;
 t_bool *set;
-uint32 line, idx = 0;
+uint32 line, idx;
+t_addr lncount = (t_addr) (mp->lines - 1);
 t_stat result = SCPE_OK;
 
-if (mp->lnorder == NULL)                                /* line connection order undefined? */
-    return SCPE_NXPAR;                                  /* "Non-existent parameter" error */
+if (mp->lnorder == NULL)                                /* if the connection order array is not defined */
+    return SCPE_NXPAR;                                  /*   then report a "Non-existent parameter" error */
 
-else if ((cptr == NULL) || (*cptr == '\0'))             /* line range not supplied? */
-    return SCPE_MISVAL;                                 /* "Missing value" error */
+else if ((cptr == NULL) || (*cptr == '\0'))             /* otherwise if a line range was not supplied */
+    return SCPE_MISVAL;                                 /*   then report a "Missing value" error */
 
-list = (int32 *) calloc (mp->lines, sizeof (int32));    /* allocate new line order array */
+else {                                                  /* otherwise */
+    min = (t_addr) (val & 0xFFFF);                      /*   split the restriction into */
+    max = (t_addr) ((val >> 16) & 0xFFFF);              /*     minimum and maximum line numbers */
 
-if (list == NULL)                                       /* allocation failed? */
-    return SCPE_MEM;                                    /* report it */
+    if (max == 0)                                       /* if the maximum line number isn't specified */
+        max = lncount;                                  /*   then use the defined maximum */
 
-set = (t_bool *) calloc (mp->lines, sizeof (t_bool));   /* allocate line set tracking array */
+    if (min > lncount || max > lncount || min > max)    /* if the restriction isn't valid */
+        return SCPE_IERR;                               /*   then report an "Internal error" */
+    }
 
-if (set == NULL) {                                      /* allocation failed? */
-    free (list);                                        /* free successful list allocation */
-    return SCPE_MEM;                                    /* report it */
+list = (int32 *) calloc (mp->lines, sizeof (int32));    /* allocate the new line order array */
+
+if (list == NULL)                                       /* if the allocation failed */
+    return SCPE_MEM;                                    /*   then report a "Memory exhausted" error */
+
+set = (t_bool *) calloc (mp->lines, sizeof (t_bool));   /* allocate the line set tracking array */
+
+if (set == NULL) {                                      /* if the allocation failed */
+    free (list);                                        /*   then free the successful list allocation */
+    return SCPE_MEM;                                    /*      and report a "Memory exhausted" error */
     }
 
 tptr = cptr + strlen (cptr);                            /* append a semicolon */
 *tptr++ = ';';                                          /*   to the command string */
-*tptr = '\0';                                           /*   to make parsing easier for get_range */
+*tptr = '\0';                                           /*     to make parsing easier */
+
+idx = 0;                                                /* initialize the index of ordered values */
+
+while (*cptr != '\0') {                                 /* while characters remain in the command string */
+    if (strncmp (cptr, "ALL;", 4) == 0) {               /*   if the parameter is "ALL" */
+        if (val != 0 || idx > 0 && idx <= max)          /*     then if some lines are restrictied or unspecified */
+            for (line = min; line <= max; line++)       /*       then fill them in sequentially */
+                if (set [line] == FALSE)                /*         setting each unspecified line */
+                    list [idx++] = line;                /*           into the line order */
+
+        cptr = cptr + 4;                                /* advance past "ALL" and the trailing semicolon */
+
+        if (*cptr != '\0')                              /* if "ALL" is not the last parameter */
+            result = SCPE_2MARG;                        /*   then report extraneous items */
+
+        break;                                          /* "ALL" terminates the order list */
+        }
 
-while (*cptr) {                                                 /* parse command string */
     cptr = get_range (NULL, cptr, &low, &high, 10, max, ';');   /* get a line range */
 
-    if (cptr == NULL) {                                 /* parsing error? */
-        result = SCPE_ARG;                              /* "Invalid argument" error */
-        break;
+    if (cptr == NULL) {                                 /* if a parsing error occurred */
+        result = SCPE_ARG;                              /*   then report an invalid argument */
+        break;                                          /*     and terminate the parse */
         }
 
-    else if ((low > max) || (high > max)) {             /* line out of range? */
-        result = SCPE_SUB;                              /* "Subscript out of range" error */
-        break;
+    else if (low < min || low > max || high > max) {    /* otherwise if the line number is invalid */
+        result = SCPE_SUB;                              /*   then report the subscript is out of range */
+        break;                                          /*     and terminate the parse */
         }
 
-    else if ((low == 0) && (high == max)) {             /* entire line range specified? */
-        list [0] = -1;                                  /* set sequential order flag */
-        idx = (uint32) max + 1;                         /* indicate no fill-in needed */
-        break;
-        }
-
-    else
-        for (line = (uint32) low; line <= (uint32) high; line++) /* see if previously specified */
-            if (set [line] == FALSE) {                  /* not already specified? */
-                set [line] = TRUE;                      /* now it is */
-                list [idx] = line;                      /* add line to connection order */
-                idx = idx + 1;                          /* bump "specified" count */
+    else                                                            /* otherwise it's a valid range */
+        for (line = (uint32) low; line <= (uint32) high; line++)    /*   so add the line(s) to the order */
+            if (set [line] == FALSE) {                              /* if the line number has not been specified */
+                set [line] = TRUE;                                  /*   then now it is */
+                list [idx++] = line;                                /*     and add it to the connection order */
                 }
     }
 
-if (result == SCPE_OK) {                                /* assignment successful? */
-    if (idx <= max)                                     /* any lines not specified? */
-        for (line = 0; line <= max; line++)             /* fill them in sequentially */
-            if (set [line] == FALSE) {                  /* specified? */
-                list [idx] = line;                      /* no, so add it */
-                idx = idx + 1;
-                }
+if (result == SCPE_OK) {                                /* if the assignment succeeded */
+    if (idx <= max)                                     /*   then if any lines were not specified */
+        list [idx] = -1;                                /*     then terminate the order list after the last one */
 
-    memcpy (mp->lnorder, list, mp->lines * sizeof (int32)); /* copy working array to connection array */
+    memcpy (mp->lnorder, list,                          /* copy the working array to the connection array */
+            mp->lines * sizeof (int32));
     }
 
-free (list);                                            /* free list allocation */
-free (set);                                             /* free set allocation */
+free (list);                                            /* free the list allocation */
+free (set);                                             /*   and the set allocation */
 
-return result;
+return result;                                          /* return the status */
 }
 
-/* Show line connection order.
+/* Show the line connection order.
 
    Parameters:
     - st   = stream on which output is to be written
@@ -1013,7 +1168,8 @@ return result;
    command is rejected.  If the first value of the connection order array is set
    to -1, then the connection order is sequential.  Otherwise, the line values
    in the array are printed as a semicolon-separated list.  Ranges are printed
-   where possible to shorten the output.
+   where possible to shorten the output.  A -1 value within the array indicates
+   the end of the order list.
 */
 
 t_stat tmxr_show_lnorder (FILE *st, UNIT *uptr, int32 val, void *desc)
@@ -1032,7 +1188,7 @@ if (*iptr < 0)                                          /* sequential order indi
 else {
     low = last = *iptr++;                               /* set first line value */
 
-    for (j = 1; j <= mp->lines; j++) {                  /* print remaining lines in order list */
+    for (j = 1; last != -1; j++) {                      /* print the remaining lines in the order list */
         if (j < mp->lines)                              /* more lines to process? */
             i = *iptr++;                                /* get next line in list */
         else                                            /* final iteration */
diff --git a/sim_tmxr.h b/sim_tmxr.h
index 6918e877..b3956edb 100644
--- a/sim_tmxr.h
+++ b/sim_tmxr.h
@@ -1,6 +1,6 @@
 /* sim_tmxr.h: terminal multiplexor definitions
 
-   Copyright (c) 2001-2019, Robert M Supnik
+   Copyright (c) 2001-2020, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -26,6 +26,7 @@
    Based on the original DZ11 simulator by Thord Nilson, as updated by
    Arthur Krewat.
 
+   23-Oct-20    JDB     Added tmxr_post_logs global routine
    19-Dec-19    JDB     Added tmxr_is_extended global hook
    19-Mar-19    JDB     Added extension pointer to TMLN structure;
                         added tmxr_read, tmxr_write, tmxr_show, tmxr_close global hooks;
@@ -123,6 +124,7 @@ void tmxr_fconns (FILE *st, TMLN *lp, int32 ln);
 void tmxr_fstats (FILE *st, TMLN *lp, int32 ln);
 t_stat tmxr_set_log (UNIT *uptr, int32 val, char *cptr, void *desc);
 t_stat tmxr_set_nolog (UNIT *uptr, int32 val, char *cptr, void *desc);
+void tmxr_post_logs (t_bool close_logs);
 t_stat tmxr_show_log (FILE *st, UNIT *uptr, int32 val, void *desc);
 t_stat tmxr_dscln (UNIT *uptr, int32 val, char *cptr, void *desc);
 int32 tmxr_rqln (TMLN *lp);