diff --git a/avr/devices/n20/boot.asm b/avr/devices/n20/boot.asm
index 48bc30f..c7a85e8 100644
--- a/avr/devices/n20/boot.asm
+++ b/avr/devices/n20/boot.asm
@@ -96,8 +96,7 @@ firmwareStart:   rjmp main ; will be overwritten when flashing
 
 
 main:
-  rjmp bootLoader ; this routine is in modules/flash/proto.asm
-
+  rjmp bootLoader ; this routine is in modules/bootloader/main.asm
 
 
 
@@ -111,52 +110,34 @@ main:
 .include "common/utils_wait_fixed.asm"
 .include "common/utils_copy_from_flash.asm"
 .include "common/utils_copy_sdram.asm"
-.include "modules/flash/bootloader.asm"
+
+.include "modules/flash/defs.asm"
+.include "modules/flash/io.asm"
+.include "modules/flash/io_attn.asm"
+.include "modules/flash/io_bitbang.asm"
 .include "modules/flash/flash.asm"
-.include "modules/flash/recv.asm"
-.include "modules/flash/send.asm"
+.include "modules/flash/flashprocess.asm"
 .include "modules/flash/wait.asm"
-.include "modules/flash/hdl_flash_start.asm"
-.include "modules/flash/hdl_flash_data.asm"
-.include "modules/flash/hdl_flash_end.asm"
-.include "modules/flash/flash_rsp.asm"
-.include "modules/flash/flash_ready.asm"
+.include "modules/bootloader/main.asm"
+
+
+
+systemSetSpeed:
+.if clock == 8000000
+  ldi r16, (1<<CLKPCE)
+  ldi r17, 0
+  out CLKPR, r16
+  out CLKPR, r17
+.endif
+
+.if clock == 1000000
+  ldi r16, (1<<CLKPCE)
+  ldi r17, (1<<CLKPS1) | (1<<CLKPS0)
+  out CLKPR, r16
+  out CLKPR, r17
+.endif
+  ret
 
 
-#if 0
-debugStop:
-  cli
-  sbi LED_SIMPLE_DDR, LED_SIMPLE_PINNUM  ; out
-  cbi LED_SIMPLE_PORT, LED_SIMPLE_PINNUM ; on
-  
-  cbi COM_ATTN_DDR, COM_ATTN_PIN          ; set ATTN port as input
-  cbi COM_ATTN_OUTPUT, COM_ATTN_PIN       ; disable internal pullup for ATTN
-  
-  ldi r18, 0
-test_loop1:
-    ldi r16, 100
-test_loop2:
-      ldi r17, 100
-test_loop3:
-        Utils_WaitNanoSecs 10000, 0, r22
-        dec r17
-      brne test_loop3
-      dec r16
-    brne test_loop2
-    sbi LED_SIMPLE_PORTIN, LED_SIMPLE_PINNUM ; toggle
-    inc r18
-    mov r19, r18
-    andi r19, 1
-    brne test1
-    sbi COM_ATTN_DDR, COM_ATTN_PIN
-    cbi COM_ATTN_OUTPUT, COM_ATTN_PIN
-    rjmp test_loop1
-test1:
-    cbi COM_ATTN_DDR, COM_ATTN_PIN
-    cbi COM_ATTN_OUTPUT, COM_ATTN_PIN
-    
-  rjmp test_loop1
-#endif
 
-