diff --git a/changelog.md b/changelog.md
index 1e43043..f87277d 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,23 @@
 ## grblHAL changelog
 
+<a name="20230217"/>20230217
+
+Core: added compile time symbols and names for remaining control inputs, rephrased two alarm messages. No functional changes.
+
+Drivers:
+
+* STM32F1xx : added support for MPG mode and option to use UART5 \(untested\) in RC variants.  
+Added support for ioports interface \(aux I/O\) and now allows pin naming for RC variants.  
+Changed RAM allocation for Cx variants to accomodate above changes, this might also allow a larger planner buffer size.  
+Fixed some inconsistencies in BOARD_MACH3_BOB \(_mach3_bob_map.h_\) - untested.  
+__NOTE:__ Cx variants are no longer possible to debug due to limited flash, only the release version can be compiled.
+
+Plugins:
+
+* Motors and plasma: updated for spindle handling refactoring.
+
+---
+
 <a name="20230213"/>Build 20230213
 
 Core:
@@ -10,7 +28,7 @@ __NOTE:__ This change is quite large, bugs may have sneaked in. Please report an
 
 Drivers:
 
-* All: updated for spindle handling refactoring.
+* All: Updated for spindle handling refactoring.
 
 * iMXRT1062: updated readme for links to updated/patched libraries for SD card \(uSDFS\) and ethernet. User should switch to the updated/patched libraries if used.
 
diff --git a/crossbar.h b/crossbar.h
index 3db9dd6..00d07cc 100644
--- a/crossbar.h
+++ b/crossbar.h
@@ -3,7 +3,7 @@
 
   Part of grblHAL
 
-  Copyright (c) 2021 Terje Io
+  Copyright (c) 2021-2023 Terje Io
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -32,6 +32,10 @@ typedef enum {
     Input_SafetyDoor,
     Input_LimitsOverride,
     Input_EStop,
+    Input_BlockDelete,
+    Input_SingleBlock,
+    Input_StopDisable,
+    Input_ProbeDisconnect,
     Input_MPGSelect,
     Input_ModeSelect = Input_MPGSelect, // Deprecated
     Input_LimitX,
@@ -55,7 +59,7 @@ typedef enum {
     Input_LimitV_Max,
     Input_MISO,
     Input_RX,
-    Input_KeypadStrobe, // To be deprecated?
+    Input_KeypadStrobe, // To be deprecated? Use Input_I2CStrobe instead.
     Input_I2CStrobe,
     Input_QEI_A,
     Input_QEI_B,
@@ -164,6 +168,10 @@ PROGMEM static const pin_name_t pin_names[] = {
    { .function = Input_SafetyDoor,          .name = "Safety door" },
    { .function = Input_LimitsOverride,      .name = "Limits override" },
    { .function = Input_EStop,               .name = "Emergency stop" },
+   { .function = Input_BlockDelete,         .name = "Block delete" },
+   { .function = Input_SingleBlock,         .name = "Single block" },
+   { .function = Input_StopDisable,         .name = "Stop disable" },
+   { .function = Input_ProbeDisconnect,     .name = "Probe disconnect" },
    { .function = Input_MPGSelect,           .name = "MPG mode select" },
    { .function = Input_LimitX,              .name = "X limit min" },
    { .function = Input_LimitX_2,            .name = "X limit min 2" },
diff --git a/messages.h b/messages.h
index 08d2328..4ce47dd 100644
--- a/messages.h
+++ b/messages.h
@@ -63,11 +63,11 @@ PROGMEM static const message_t messages[] = {
     { .id = Message_RestoreDefaults, .msg = "Restoring defaults" },
     { .id = Message_SpindleRestore, .msg = "Restoring spindle" },
     { .id = Message_SleepMode, .msg = "Sleeping" },
-    { .id = Message_EStop, .msg = "Emergency stop" },
+    { .id = Message_EStop, .msg = "Emergency stop - clear, then reset to continue" },
     { .id = Message_HomingCycleRequired, .msg = "Homing cycle required" },
     { .id = Message_CycleStartToRerun, .msg = "Press cycle start to rerun job" },
     { .id = Message_ReferenceTLOEstablished, .msg = "Reference tool length offset established" },
-    { .id = Message_MotorFault, .msg = "Motor fault" }
+    { .id = Message_MotorFault, .msg = "Motor fault - clear, then reset to continue" }
 };
 
 #endif
diff --git a/motor_pins.h b/motor_pins.h
index 528b0a9..409b1a8 100644
--- a/motor_pins.h
+++ b/motor_pins.h
@@ -762,16 +762,22 @@
 
 #if N_AXIS == 3
 #define LIMIT_MASK (X_LIMIT_BIT|Y_LIMIT_BIT|Z_LIMIT_BIT)
+#define LIMIT_MASK_SUM (X_LIMIT_BIT+Y_LIMIT_BIT+Z_LIMIT_BIT)
 #elif N_AXIS == 4
 #define LIMIT_MASK (X_LIMIT_BIT|Y_LIMIT_BIT|Z_LIMIT_BIT|A_LIMIT_BIT)
+#define LIMIT_MASK_SUM (X_LIMIT_BIT+Y_LIMIT_BIT+Z_LIMIT_BIT+A_LIMIT_BIT)
 #elif N_AXIS == 5
 #define LIMIT_MASK (X_LIMIT_BIT|Y_LIMIT_BIT|Z_LIMIT_BIT|A_LIMIT_BIT|B_LIMIT_BIT)
+#define LIMIT_MASK_SUM (X_LIMIT_BIT+Y_LIMIT_BIT+Z_LIMIT_BIT+A_LIMIT_BIT+B_LIMIT_BITT)
 #elif N_AXIS == 6
 #define LIMIT_MASK (X_LIMIT_BIT|Y_LIMIT_BIT|Z_LIMIT_BIT|A_LIMIT_BIT|B_LIMIT_BIT|C_LIMIT_BIT)
+#define LIMIT_MASK_SUM (X_LIMIT_BIT+Y_LIMIT_BIT+Z_LIMIT_BIT+A_LIMIT_BIT+B_LIMIT_BIT+C_LIMIT_BIT)
 #elif N_AXIS == 7
 #define LIMIT_MASK (X_LIMIT_BIT|Y_LIMIT_BIT|Z_LIMIT_BIT|A_LIMIT_BIT|B_LIMIT_BIT|C_LIMIT_BIT|U_LIMIT_BIT)
+#define LIMIT_MASK_SUM (X_LIMIT_BIT+Y_LIMIT_BIT+Z_LIMIT_BIT+A_LIMIT_BIT+B_LIMIT_BIT+C_LIMIT_BIT+U_LIMIT_BIT)
 #else
 #define LIMIT_MASK (X_LIMIT_BIT|Y_LIMIT_BIT|Z_LIMIT_BIT|A_LIMIT_BIT|B_LIMIT_BIT|C_LIMIT_BIT|U_LIMIT_BIT|V_LIMIT_BIT)
+#define LIMIT_MASK_SUM (X_LIMIT_BIT+Y_LIMIT_BIT+Z_LIMIT_BIT+A_LIMIT_BIT+B_LIMIT_BIT+C_LIMIT_BIT+U_LIMIT_BIT+V_LIMIT_BIT)
 #endif
 
 #endif // LIMIT_MASK
diff --git a/pin_bits_masks.h b/pin_bits_masks.h
index cb6c2c4..d6efe9d 100644
--- a/pin_bits_masks.h
+++ b/pin_bits_masks.h
@@ -5,7 +5,7 @@
 
   Part of grblHAL
 
-  Copyright (c) 2021-2022 Terje Io
+  Copyright (c) 2021-2023 Terje Io
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,7 +21,11 @@
   along with Grbl.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+// Control input signals
+
+// Define the CONTROL_PORT symbol as a shorthand in the *_map.h file if all control inputs share the same port.
 #ifdef CONTROL_PORT
+
 #ifndef RESET_PORT
 #define RESET_PORT CONTROL_PORT
 #endif
@@ -31,10 +35,35 @@
 #ifndef CYCLE_START_PORT
 #define CYCLE_START_PORT CONTROL_PORT
 #endif
+#ifndef ESTOP_PORT
+#define ESTOP_PORT CONTROL_PORT
+#endif
+#ifndef PROBE_DISCONNECT_PORT
+#define PROBE_DISCONNECT_PORT CONTROL_PORT
+#endif
+#ifndef STOP_DISABLE_PORT
+#define STOP_DISABLE_PORT CONTROL_PORT
+#endif
+#ifndef BLOCK_DELETE_PORT
+#define BLOCK_DELETE_PORT CONTROL_PORT
+#endif
+#ifndef SINGLE_BLOCK_PORT
+#define SINGLE_BLOCK_PORT CONTROL_PORT
+#endif
+#ifndef MOTOR_FAULT_PORT
+#define MOTOR_FAULT_PORT CONTROL_PORT
+#endif
+#ifndef MOTOR_WARNING_PORT
+#define MOTOR_WARNING_PORT CONTROL_PORT
+#endif
+#ifndef LIMITS_OVERRIDE_PORT
+#define LIMITS_OVERRIDE_PORT CONTROL_PORT
+#endif
 #if SAFETY_DOOR_ENABLE && !defined(SAFETY_DOOR_PORT)
 #define SAFETY_DOOR_PORT CONTROL_PORT
 #endif
-#endif
+
+#endif // CONTROL_PORT
 
 #ifndef RESET_BIT
 #ifdef RESET_PIN
@@ -68,14 +97,88 @@
 #endif
 #endif
 
+#ifndef ESTOP_BIT
+#ifdef ESTOP_PIN
+#define ESTOP_BIT (1<<ESTOP_PIN)
+#else
+#define ESTOP_BIT 0
+#endif
+#endif
+
+#ifndef PROBE_DISCONNECT_BIT
+#ifdef PROBE_DISCONNECT_PIN
+#define PROBE_DISCONNECT_BIT (1<<PROBE_DISCONNECT_PIN)
+#else
+#define PROBE_DISCONNECT_BIT 0
+#endif
+#endif
+
+#ifndef STOP_DISABLE_BIT
+#ifdef STOP_DISABLE_PIN
+#define STOP_DISABLE_BIT (1<<STOP_DISABLE_PIN)
+#else
+#define STOP_DISABLE_BIT 0
+#endif
+#endif
+
+#ifndef BLOCK_DELETE_BIT
+#ifdef BLOCK_DELETE_PIN
+#define BLOCK_DELETE_BIT (1<<BLOCK_DELETE_PIN)
+#else
+#define BLOCK_DELETE_BIT 0
+#endif
+#endif
+
+#ifndef SINGLE_BLOCK_BIT
+#ifdef SINGLE_BLOCK_PIN
+#define SINGLE_BLOCK_BIT (1<<SINGLE_BLOCK_PIN)
+#else
+#define SINGLE_BLOCK_BIT 0
+#endif
+#endif
+
+#ifndef MOTOR_FAULT_BIT
+#ifdef MOTOR_FAULT_PIN
+#define MOTOR_FAULT_BIT (1<<MOTOR_FAULT_PIN)
+#else
+#define MOTOR_FAULT_BIT 0
+#endif
+#endif
+
+#ifndef MOTOR_WARNING_BIT
+#ifdef MOTOR_WARNING_PIN
+#define MOTOR_WARNING_BIT (1<<MOTOR_WARNING_PIN)
+#else
+#define MOTOR_WARNING_BIT 0
+#endif
+#endif
+
+#ifndef LIMITS_OVERRIDE_BIT
+#ifdef LIMITS_OVERRIDE_PIN
+#define LIMITS_OVERRIDE_BIT (1<<LIMITS_OVERRIDE_PIN)
+#else
+#define LIMITS_OVERRIDE_BIT 0
+#endif
+#endif
+
 #ifndef CONTROL_MASK
 #if SAFETY_DOOR_ENABLE
-#define CONTROL_MASK    (RESET_BIT|FEED_HOLD_BIT|CYCLE_START_BIT|SAFETY_DOOR_BIT)
+#define CONTROL_MASK (RESET_BIT|FEED_HOLD_BIT|CYCLE_START_BIT|ESTOP_BIT|PROBE_DISCONNECT_BIT|STOP_DISABLE_BIT|BLOCK_DELETE_BIT|SINGLE_BLOCK_BIT|MOTOR_FAULT_BIT|MOTOR_WARNING_BIT|LIMITS_OVERRIDE_BIT|SAFETY_DOOR_BIT)
+#define CONTROL_MASK_SUM (RESET_BIT+FEED_HOLD_BIT+CYCLE_START_BIT+ESTOP_BIT+PROBE_DISCONNECT_BIT+STOP_DISABLE_BIT+BLOCK_DELETE_BIT+SINGLE_BLOCK_BIT+MOTOR_FAULT_BIT+MOTOR_WARNING_BIT+LIMITS_OVERRIDE_BIT+SAFETY_DOOR_BIT)
 #else
-#define CONTROL_MASK    (RESET_BIT|FEED_HOLD_BIT|CYCLE_START_BIT)
+#define CONTROL_MASK (RESET_BIT|FEED_HOLD_BIT|CYCLE_START_BIT|ESTOP_BIT|PROBE_DISCONNECT_BIT|STOP_DISABLE_BIT|BLOCK_DELETE_BIT|SINGLE_BLOCK_BIT|MOTOR_FAULT_BIT|MOTOR_WARNING_BIT|LIMITS_OVERRIDE_BIT)
+#define CONTROL_MASK_SUM (RESET_BIT+FEED_HOLD_BIT+CYCLE_START_BIT+ESTOP_BIT+PROBE_DISCONNECT_BIT+STOP_DISABLE_BIT+BLOCK_DELETE_BIT+SINGLE_BLOCK_BIT+MOTOR_FAULT_BIT+MOTOR_WARNING_BIT+LIMITS_OVERRIDE_BIT)
 #endif
 #endif
 
+// Probe input signal
+
+#if defined(PROBE_PIN) && !defined(PROBE_BIT)
+#define PROBE_BIT (1<<PROBE_PIN)
+#endif
+
+// Output Signals
+
 #if defined(SPINDLE_ENABLE_PIN) && !defined(SPINDLE_ENABLE_BIT)
 #define SPINDLE_ENABLE_BIT (1<<SPINDLE_ENABLE_PIN)
 #endif
@@ -90,10 +193,6 @@
 #define COOLANT_MIST_BIT (1<<COOLANT_MIST_PIN)
 #endif
 
-#if defined(PROBE_PIN) && !defined(PROBE_BIT)
-#define PROBE_BIT (1<<PROBE_PIN)
-#endif
-
 #if defined(I2C_STROBE_PIN) && !defined(I2C_STROBE_BIT)
 #define I2C_STROBE_BIT (1<<I2C_STROBE_PIN)
 #endif
@@ -102,6 +201,8 @@
 #define RTS_BIT (1<<RTS_PIN)
 #endif
 
+// Auxillary input signals
+
 #ifdef AUXINPUT0_PIN
 #define AUXINPUT0_BIT (1<<AUXINPUT0_PIN)
 #else
@@ -145,6 +246,7 @@
 
 #ifndef AUXINPUT_MASK
 #define AUXINPUT_MASK (AUXINPUT0_BIT|AUXINPUT1_BIT|AUXINPUT2_BIT|AUXINPUT3_BIT|AUXINPUT4_BIT|AUXINPUT5_BIT|AUXINPUT6_BIT|AUXINPUT7_BIT)
+#define AUXINPUT_MASK_SUM (AUXINPUT0_BIT+AUXINPUT1_BIT+AUXINPUT2_BIT+AUXINPUT3_BIT+AUXINPUT4_BIT+AUXINPUT5_BIT+AUXINPUT6_BIT+AUXINPUT7_BIT)
 #endif
 
 /*EOF*/