diff --git a/DMD_Monochrome_Parallel.h b/DMD_Monochrome_Parallel.h
index 0ab846f..744cf17 100644
--- a/DMD_Monochrome_Parallel.h
+++ b/DMD_Monochrome_Parallel.h
@@ -17,7 +17,7 @@ class DMD_Monochrome_Parallel :
 	void shiftScreen(int8_t step)  override;
 
 	// changing connect scheme not allowed for Parallel
-	virtual void setConnectScheme(uint8_t sch) override  = 0;
+	virtual void setConnectScheme(uint8_t sch) override {} ;
 
 protected:
 
diff --git a/DMD_STM32a.h b/DMD_STM32a.h
index 20310cc..96a2551 100644
--- a/DMD_STM32a.h
+++ b/DMD_STM32a.h
@@ -3,11 +3,11 @@
 /*--------------------------------------------------------------------------------------
  DMD_STM32a.h  - advansed version of DMD_STM32.h
 
- ****** VERSION 0.9.5 ******
+ ****** VERSION 0.9.3 ******
 
  DMD_STM32.h  - STM32 port of DMD.h library
 
- adapted by Dmitry Dmitriev (c) 2019-2023
+ adapted by Dmitry Dmitriev (c) 2019-2022
 
  =======  based on =========
 
@@ -242,8 +242,8 @@ class DMD : public Adafruit_GFX
 #endif
 	virtual void set_mux(uint8_t curr_row);
 	virtual void drawHByte(int16_t x, int16_t y, uint8_t hbyte, uint16_t bsize, uint8_t* fg_col_bytes,
-		uint8_t* bg_col_bytes)  =0 ;
-	virtual void getColorBytes(uint8_t* cbytes, uint16_t color)  =0 ;
+		uint8_t* bg_col_bytes) {} ;
+	virtual void getColorBytes(uint8_t* cbytes, uint16_t color) {};
 	
 	// pins
 	const uint8_t mux_cnt = 2;