diff --git a/g2core/board/Archim/hardware.h b/g2core/board/Archim/hardware.h
index 7b3f05c4..d66cae7d 100755
--- a/g2core/board/Archim/hardware.h
+++ b/g2core/board/Archim/hardware.h
@@ -82,8 +82,6 @@ using Motate::OutputPin;
  * Global System Defines *
  *************************/
 
-#undef F_CPU							// CPU clock - set for delays
-#define F_CPU 84000000UL
 #define MILLISECONDS_PER_TICK 1			// MS for system tick (systick * N)
 #define SYS_ID_DIGITS 12                // actual digits in system ID (up to 16)
 #define SYS_ID_LEN 16					// total length including dashes and NUL
diff --git a/g2core/board/ArduinoDue/hardware.h b/g2core/board/ArduinoDue/hardware.h
index ed513965..1b5bbe6b 100755
--- a/g2core/board/ArduinoDue/hardware.h
+++ b/g2core/board/ArduinoDue/hardware.h
@@ -84,8 +84,6 @@ using Motate::OutputPin;
  * Global System Defines *
  *************************/
 
-#undef F_CPU							// CPU clock - set for delays
-#define F_CPU 84000000UL
 #define MILLISECONDS_PER_TICK 1			// MS for system tick (systick * N)
 #define SYS_ID_DIGITS 12                // actual digits in system ID (up to 16)
 #define SYS_ID_LEN 16					// total length including dashes and NUL
diff --git a/g2core/board/G2v9/hardware.h b/g2core/board/G2v9/hardware.h
index 68fa77a5..835dfc44 100755
--- a/g2core/board/G2v9/hardware.h
+++ b/g2core/board/G2v9/hardware.h
@@ -84,8 +84,6 @@ using Motate::OutputPin;
  * Global System Defines *
  *************************/
 
-#undef F_CPU							// CPU clock - set for delays
-#define F_CPU 84000000UL
 #define MILLISECONDS_PER_TICK 1			// MS for system tick (systick * N)
 #define SYS_ID_DIGITS 12                // actual digits in system ID (up to 16)
 #define SYS_ID_LEN 16					// total length including dashes and NUL
diff --git a/g2core/board/gquadratic/hardware.h b/g2core/board/gquadratic/hardware.h
index 3b4fc7bc..069cb2ba 100755
--- a/g2core/board/gquadratic/hardware.h
+++ b/g2core/board/gquadratic/hardware.h
@@ -85,8 +85,6 @@ using Motate::OutputPin;
  * Global System Defines *
  *************************/
 
-#undef F_CPU  // CPU clock - set for delays
-#define F_CPU 84000000UL
 #define MILLISECONDS_PER_TICK 1  // MS for system tick (systick * N)
 #define SYS_ID_DIGITS 12         // actual digits in system ID (up to 16)
 #define SYS_ID_LEN 16            // total length including dashes and NUL
diff --git a/g2core/board/gquintic/hardware.h b/g2core/board/gquintic/hardware.h
index 5dbe9ac3..0fb2d541 100755
--- a/g2core/board/gquintic/hardware.h
+++ b/g2core/board/gquintic/hardware.h
@@ -83,8 +83,6 @@ using Motate::OutputPin;
  * Global System Defines *
  *************************/
 
-#undef F_CPU                        // CPU clock - set for delays
-#define F_CPU 84000000UL
 #define MILLISECONDS_PER_TICK 1     // MS for system tick (systick * N)
 #define SYS_ID_DIGITS 12            // actual digits in system ID (up to 16)
 #define SYS_ID_LEN 16               // total length including dashes and NUL
diff --git a/g2core/board/printrboardg2/hardware.h b/g2core/board/printrboardg2/hardware.h
index 91af3784..6046c789 100755
--- a/g2core/board/printrboardg2/hardware.h
+++ b/g2core/board/printrboardg2/hardware.h
@@ -82,8 +82,6 @@ using Motate::OutputPin;
  * Global System Defines *
  *************************/
 
-#undef F_CPU							// CPU clock - set for delays
-#define F_CPU 84000000UL
 #define MILLISECONDS_PER_TICK 1			// MS for system tick (systick * N)
 #define SYS_ID_DIGITS 12                // actual digits in system ID (up to 16)
 #define SYS_ID_LEN 16					// total length including dashes and NUL
diff --git a/g2core/board/sbv300/hardware.h b/g2core/board/sbv300/hardware.h
index 8b930d1e..0e576ab4 100755
--- a/g2core/board/sbv300/hardware.h
+++ b/g2core/board/sbv300/hardware.h
@@ -82,8 +82,6 @@ using Motate::OutputPin;
  * Global System Defines *
  *************************/
 
-#undef F_CPU							// CPU clock - set for delays
-#define F_CPU 84000000UL
 #define MILLISECONDS_PER_TICK 1			// MS for system tick (systick * N)
 #define SYS_ID_DIGITS 12                // actual digits in system ID (up to 16)
 #define SYS_ID_LEN 16					// total length including dashes and NUL
diff --git a/g2core/pwm.cpp b/g2core/pwm.cpp
index f141ea8d..82248fdf 100755
--- a/g2core/pwm.cpp
+++ b/g2core/pwm.cpp
@@ -45,8 +45,8 @@ static Motate::PWMOutputPin<Motate::kSpindle_Pwm2PinNumber> secondary_pwm_pin;
 //#define PWM_TIMER_TYPE    TC1_struct      // PWM uses TC1's
 #define PWM_TIMER_t    TC1_t                // PWM uses TC1's
 #define PWM_TIMER_DISABLE 0                 // turn timer off (clock = 0 Hz)
-#define PWM_MAX_FREQ (F_CPU/256)            // max frequency with 8-bits duty cycle precision
-#define PWM_MIN_FREQ (F_CPU/64/65536)       // min frequency with supported prescaling
+//#define PWM_MAX_FREQ (F_CPU/256)            // max frequency with 8-bits duty cycle precision
+//#define PWM_MIN_FREQ (F_CPU/64/65536)       // min frequency with supported prescaling
 
 // channel specific defines
 /* CLKSEL is used to configure default PWM clock operating ranges
@@ -95,8 +95,8 @@ void pwm_init() {}
 stat_t pwm_set_freq(uint8_t chan, float freq)
 {
     if (chan > PWMS) { return (STAT_NO_SUCH_DEVICE);}
-    if (freq < PWM_MIN_FREQ) { return (STAT_INPUT_LESS_THAN_MIN_VALUE);}
-    if (freq > PWM_MAX_FREQ) { return (STAT_INPUT_EXCEEDS_MAX_VALUE);}
+    //if (freq < PWM_MIN_FREQ) { return (STAT_INPUT_LESS_THAN_MIN_VALUE);}
+    //if (freq > PWM_MAX_FREQ) { return (STAT_INPUT_EXCEEDS_MAX_VALUE);}
 
     if (chan == PWM_1) {
         spindle_pwm_pin.setFrequency(freq);
diff --git a/g2core/stepper.cpp b/g2core/stepper.cpp
index 32c70d5e..74b432df 100644
--- a/g2core/stepper.cpp
+++ b/g2core/stepper.cpp
@@ -51,7 +51,7 @@ static stRunSingleton_t st_run;
 static void _load_move(void);
 
 // handy macro
-#define _f_to_period(f) (uint16_t)((float)F_CPU / (float)f)
+//#define _f_to_period(f) (uint16_t)((float)F_CPU / (float)f)
 
 /**** Setup motate ****/
 
@@ -658,7 +658,7 @@ stat_t st_prep_line(float travel_steps[], float following_error[], float segment
     // - dda_ticks is the integer number of DDA clock ticks needed to play out the segment
     // - ticks_X_substeps is the maximum depth of the DDA accumulator (as a negative number)
 
-    st_pre.dda_period = _f_to_period(FREQUENCY_DDA);                // FYI: this is a constant
+    //st_pre.dda_period = _f_to_period(FREQUENCY_DDA);                // FYI: this is a constant
     st_pre.dda_ticks = (int32_t)(segment_time * 60 * FREQUENCY_DDA);// NB: converts minutes to seconds
     st_pre.dda_ticks_X_substeps = st_pre.dda_ticks * DDA_SUBSTEPS;
 
@@ -753,7 +753,7 @@ void st_prep_command(void *bf)
 void st_prep_dwell(float microseconds)
 {
     st_pre.block_type = BLOCK_TYPE_DWELL;
-    st_pre.dda_period = _f_to_period(FREQUENCY_DWELL);
+    //st_pre.dda_period = _f_to_period(FREQUENCY_DWELL);
     st_pre.dda_ticks = (uint32_t)((microseconds/1000000) * FREQUENCY_DWELL);
     st_pre.buffer_state = PREP_BUFFER_OWNED_BY_LOADER;    // signal that prep buffer is ready
 }
diff --git a/g2core/stepper.h b/g2core/stepper.h
index 0a973ad7..6c1967dd 100644
--- a/g2core/stepper.h
+++ b/g2core/stepper.h
@@ -413,7 +413,7 @@ typedef struct stPrepSingleton {
     struct mpBuffer *bf;                    // static pointer to relevant buffer
     blockType block_type;                   // move type (requires planner.h)
 
-    uint16_t dda_period;                    // DDA or dwell clock period setting
+    //uint16_t dda_period;                    // DDA or dwell clock period setting (No longer used)
     uint32_t dda_ticks;                     // DDA or dwell ticks for the move
     uint32_t dda_ticks_X_substeps;          // DDA ticks scaled by substep factor
     stPrepMotor_t mot[MOTORS];              // prep time motor structs