diff --git a/changelog.md b/changelog.md
index 9c5a5a8..b87965e 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,17 +1,33 @@
 ## grblHAL changelog
 
+<a name="20251105">20251105
+
+Core:
+
+* Added field for programmed timer period to HAL timer struct.
+
+Drivers:
+
+* STM32F4xx: implemented accurate continuous timer mode in timer HAL API. Fix for incorrect clock tree setup for BTT Octopus Board.
+
+Plugins:
+
+* Spindle, stepper: changed to use continuous timer mode, when available, for accurate RPM. Ref. issue [#41](https://github.com/grblHAL/Plugins_spindle/issues/41)
+
+---
+
 <a name="20251023">Build 20251023
 
 Core:
 
 * Workaround for POS (Power on self-test) failure messages(s) not output on "native" USB connect.
 
-* Fixed handling of NVS buffer allocation, size was not increased as expected when physical NVS is capable of holding more than 2 Kbytes.
+* Fixed handling of NVS buffer allocation, size was not increased as expected when physical NVS is capable of holding more than 2 Kbytes.  
 This could lead to POS failure or plugins not initializing when a large tool table is configured.
 
 Drivers:
 
-* Simulator: fix for double free bug, ref. issue [#17](https://github.com/grblHAL/Simulator/issues/17) and block reporting not working.
+* Simulator: fix for double free bug, ref. issue [#17](https://github.com/grblHAL/Simulator/issues/17), and block reporting not working.
 
 Plugins:
 
diff --git a/hal.h b/hal.h
index 69ba0a0..26bbe71 100644
--- a/hal.h
+++ b/hal.h
@@ -76,7 +76,8 @@ typedef union {
                  rtc                         :1,
                  rtc_set                     :1,
                  bltouch_probe               :1,
-                 unassigned                  :4;
+                 modbus_rtu                  :1, // Modbus RTU stream is enabled.
+                 unassigned                  :3;
     };
 } driver_cap_t;
 
@@ -522,6 +523,7 @@ typedef void (*timer_irq_handler_ptr)(void *context);
 typedef struct {
     void *context;                          //!< Pointer to data to be passed on to the interrupt handlers
     bool single_shot;                       //!< Set to true if timer is single shot
+    uint32_t period;                        //!< Current value for period register
     timer_irq_handler_ptr timeout_callback; //!< Pointer to main timeout callback
     uint32_t irq0;                          //!< Compare value for compare interrupt 0
     timer_irq_handler_ptr irq0_callback;    //!< Pointer to compare interrupt 0 callback