diff --git a/README.md b/README.md
index 4983daa..dd68d11 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@ This is a GTK+ 3.0 implementation of an AT&T / Teletype DMD 5620 emulator.
 
 ## Status
 
-Version: 1.4.1
+Version: 2.0.0
 
 This is an actively developed project.
 
@@ -42,8 +42,6 @@ AT&T DMD 5620 Terminal emulator.
 
 -h, --help                display help and exit
 -v, --version             display version and exit
--V, --verbose             display verbose output
--D, --delete              backspace sends ^? (DEL) instead of ^H
 -t, --trace FILE          trace to FILE
 -d, --device DEV          serial port name
 -s, --shell SHELL         execute SHELL instead of default user shell
diff --git a/dmd5620.man b/dmd5620.man
index 53771c6..660f58e 100644
--- a/dmd5620.man
+++ b/dmd5620.man
@@ -5,11 +5,9 @@ dmd5620 \- AT&T DMD 5620 Terminal Emulator
 .B dmd5620
 [\fB\--help\fR]
 [\fB\--version\fR]
-[\fB\--verbose\fR]
-[\fB\--delete\fR]
 [\fB\--shell\fR \fISHELL\fR|\fB\--device\fR \fIDEVICE\fR]
 [\fB\--nvram\fR \fIFILE\fR]
-[\fB\--trace\fR \fIFILE\fR]
+[\fB\--firmware\fR \fI"VERSION"\fR]
 .SH DESCRIPTION
 .B dmd5620
 AT&T DMD 5620 Terminal emulator with support for XT layers protocol.
@@ -21,16 +19,8 @@ Displays help and exits.
 .BR \-v ", " \-\-version
 Displays version and exits.
 .TP
-.BR \-V ", " \-\-verbose
-Print verbose logging to stdout.
-.TP
-.BR \-D ", " \-\-delete
-Send a delete character ^? (0x7F hex) when the backspace key is pressed. By
-default, ^H (0x08 hex) is sent.
-.TP
 .BR \-s ", " \-\-shell " " \fISHELL\fR
-Execute the program \fISHELL\fR, e.g. \"/bin/sh\". (Either
-\fB\-\-shell\fR or \fB\-\-device\fR is required)
+Execute the program \fISHELL\fR, e.g. "/bin/sh".
 .TP
 .BR \-d ", " \-\-device " " \fIDEVICE\fR
 Connect to physical device \fIDEVICE\fR, e.g. "/dev/ttyS0" or
@@ -39,8 +29,10 @@ Connect to physical device \fIDEVICE\fR, e.g. "/dev/ttyS0" or
 .BR \-n ", " \-\-nvram  " " \fIFILE\fR
 Store NVRAM state in file \fIFILE\fR. No default.
 .TP
-.BR \-t ", " \-\-trace  " " \fIFILE\fR
-Allow logging verbose system execution trace to \fIFILE\fR.
+.BR \-f ", " \-\-firmware " " \fI"VERSION"\fR
+Select firmare version. \fI"VERSION"\fR is a string, and must
+be one of either \fB"8;7;3"\fR or \fB"8;7;5"\fR. The default version
+if not specified is \fB"8;7;5"\fR.
 .SH KEYMAP
 .TP
 .BR F1\-F8
@@ -52,9 +44,6 @@ Terminal SETUP key
 .BR SHIFT\+F9
 Terminal RESET key
 .TP
-.BR F10
-Enable or disable execution tracing, if the \fB\-\-trace\fR option has
-been used.
 .SH CONNECTING TO VIRTUAL SERIAL PORTS
 The \fB\-\-device\fR option can be used with \fBsocat\fR to set up a
 virtual serial port to a SIMH instance. For example:
@@ -67,11 +56,6 @@ This command on Linux will open a virtual serial port connected to
 \fB192.168.80.100\fR on port \fB8888\fR. The port device will be
 something like \fB/dev/pts/1\fR, and the \fB\-\-device\fR flag can
 then be used to connect to this virtual serial port.
-.SH TERMINAL EXECUTION TRACING
-The \fB\-\-trace\fR option allows verbose tracing of WE32100 CPU
-instructions to the specified file. Tracing is turned on or off by
-pressing the \fBF10\fR key. \fITracing execution is extremely expensive
-and should be used with care, it will degrade performance!\fR
 .SH USING SVR3 LAYERS
 One of the primary featuers of dmd5620 is support for the System V Release 3
 \fIlayers\fR program. Real DMD5620 terminals were hard-wired directly
@@ -87,6 +71,15 @@ Options", either with the mouse or by pressing F2. Next, select toggle
 .PP
 "Encoding" will ensure that telnet and SSH control characters are properly
 escaped.
+.SH SAVING NVRAM
+All terminal settings are forgotten on shutdown. To save terminal
+settings, the contents of NVRAM must be stored in a file using 
+the \fB\-\-nvram\fR flag.
+.PP
+\fINote that the NVRAM format is different between firmware versions!\fR
+Using the same NVRAM file on an \fB8;7;5\fR firmware terminal 
+and an \fB8;7;3\fR firwmare terminal is NOT SUPPORTED and will result
+in undesirable behavior!
 .SH KNOWN ISSUES
 .IP \(bu 3
 System V Release 3 \fIlayers\fR does not work when using Telnet to connect to a
diff --git a/dmd_core b/dmd_core
index 24acb44..03d0d36 160000
--- a/dmd_core
+++ b/dmd_core
@@ -1 +1 @@
-Subproject commit 24acb4415d7c719aaa9280cbb15c184cd6268699
+Subproject commit 03d0d36061e1dad2f3b0e3d1d670c817f0cf056f
diff --git a/src/dmd_5620.c b/src/dmd_5620.c
index 2ea7859..b01eab5 100644
--- a/src/dmd_5620.c
+++ b/src/dmd_5620.c
@@ -73,8 +73,6 @@ gint64 previous_clock = -1;
 uint8_t previous_vram[VIDRAM_SIZE];
 struct pollfd fds[2];
 pid_t shell_pid;
-int erase_is_delete = FALSE;
-int verbose = FALSE;
 volatile int window_beep = FALSE;
 volatile int dmd_thread_run = TRUE;
 int sigint_count = 0;
@@ -389,18 +387,12 @@ pty_io_poll()
 
             for (i = 0; i < b_read; i++) {
                 dmd_rs232_rx(tx_buf[i] & 0xff);
-                if (verbose) {
-                    printf("<--- PTY rx_char[%02d]: %02x %c\n", i, tx_buf[i] & 0xff, PCHAR(tx_buf[i]));
-                }
             }
         }
     }
 
     i = 0;
     while (dmd_rs232_tx(&txc) == 0) {
-        if (verbose) {
-            printf("---> PTY tx_char[%02d]: %02x %c\n", i++, txc & 0xff, PCHAR(txc));
-        }
         if (write(pty_master, &txc, 1) < 0) {
             fprintf(stderr, "Error %d from write: %s\n", errno, strerror(errno));
         }
@@ -467,18 +459,12 @@ tty_io_poll()
 
             for (i = 0; i < b_read; i++) {
                 dmd_rs232_rx(tx_buf[i] & 0xff);
-                if (verbose) {
-                    printf("<--- TTY rx_char[%02d]: %02x %c\n", i, tx_buf[i] & 0xff, PCHAR(tx_buf[i]));
-                }
             }
         }
     }
 
     i = 0;
     while (dmd_rs232_tx(&txc) == 0) {
-        if (verbose) {
-            printf("---> TTY tx_char[%02d]: %02x %c\n", i++, txc & 0xff, PCHAR(txc));
-        }
         if (write(tty_fd, &txc, 1) < 0) {
             fprintf(stderr, "error %d during write: %s\n", errno, strerror(errno));
         }
@@ -701,6 +687,8 @@ gtk_setup(int *argc, char ***argv)
 
     gtk_widget_set_size_request(drawing_area, 800, 1024);
 
+    gtk_window_set_resizable(GTK_WINDOW(main_window), FALSE);
+
     gtk_container_add(GTK_CONTAINER(main_window), drawing_area);
 
     /* Set up the animation handler, which will step the simulation
@@ -736,7 +724,6 @@ gtk_setup(int *argc, char ***argv)
 struct option long_options[] = {
     {"help", no_argument, 0, 'h'},
     {"version", no_argument, 0, 'v'},
-    {"verbose", no_argument, 0, 'V'},
     {"delete", no_argument, 0, 'D'},
     {"firmware", required_argument, 0, 'f'},
     {"shell", required_argument, 0, 's'},
@@ -752,21 +739,23 @@ void usage()
     printf("-h, --help                display help and exit\n");
     printf("-v, --version             display version and exit\n");
     printf("-f, --firmware VER        Firmware version 1 or 2\n");
-    printf("-V, --verbose             display verbose output\n");
     printf("-D, --delete              backspace sends ^? (DEL) instead of ^H\n");
     printf("-d, --device DEV          serial port name\n");
     printf("-s, --shell SHELL         execute SHELL instead of default user shell\n");
     printf("-n, --nvram FILE          store nvram state in FILE\n");
 }
 
+const char *FIRMWARE_873 = "8;7;3";
+const char *FIRMWARE_875 = "8;7;5";
+
 int
 main(int argc, char *argv[])
 {
     int c, errflg = 0;
     char *shell = NULL;
     char *device = NULL;
+    char *firmware = NULL;
     int size;
-    int firmware_version = DEFAULT_FIRMWARE_VERSION;
     uint8_t nvram_buf[NVRAM_SIZE];
     FILE *fp;
     struct stat sb;
@@ -790,15 +779,9 @@ main(int argc, char *argv[])
         case 'h':
             usage();
             exit(0);
-        case 'D':
-            erase_is_delete = TRUE;
-            break;
         case 'v':
             printf("Version: %s\n", VERSION_STRING);
             exit(0);
-        case 'V':
-            verbose = TRUE;
-            break;
         case 'n':
             nvram = optarg;
             break;
@@ -809,7 +792,7 @@ main(int argc, char *argv[])
             device = optarg;
             break;
         case 'f':
-            firmware_version = atoi(optarg);
+            firmware = optarg;
             break;
         case '?':
             fprintf(stderr, "Unrecognized option: -%c\n", optopt);
@@ -852,14 +835,17 @@ main(int argc, char *argv[])
         tty_init(tty_fd);
     }
 
-    if (firmware_version != 1 && firmware_version != 2) {
-        fprintf(stderr, "--firmware must be one of either '1' or '2'\n");
+    /* Initialize the CPU */
+    if (firmware == NULL || strncmp(FIRMWARE_875, firmware, 5) == 0) {
+        dmd_init(2);
+    } else if (strncmp(FIRMWARE_873, firmware, 5) == 0) {
+        dmd_init(1);
+    } else {
+        fprintf(stderr, "--firmware must be one of either \"%s\" or \"%s\".\n",
+                FIRMWARE_873, FIRMWARE_875);
         return -1;
     }
 
-    /* Initialize the CPU */
-    dmd_init(firmware_version);
-
     /* Load NVRAM, if any */
     if (nvram != NULL) {
         fp = fopen(nvram, "r");
diff --git a/src/version.h b/src/version.h
index becd2ef..1f3b5e8 100644
--- a/src/version.h
+++ b/src/version.h
@@ -27,8 +27,8 @@
 #ifndef __VERSION_H__
 #define __VERSION_H__
 
-#define VERSION_MAJOR 1
-#define VERSION_MINOR 4
+#define VERSION_MAJOR 2
+#define VERSION_MINOR 0
 #define VERSION_BUILD 0
 
 #endif