diff --git a/avr/usbload/mmc.c b/avr/usbload/mmc.c
index b6adbd2..3c1036b 100644
--- a/avr/usbload/mmc.c
+++ b/avr/usbload/mmc.c
@@ -5,21 +5,21 @@ uint8_t mmc_init()
     uint16_t Timeout = 0, i;
 
     // Konfiguration des Ports an der die MMC/SD-Karte angeschlossen wurde
-    DDRB |= ((1 << MMC_DO) | (1 << MMC_CS) | (1 << MMC_CLK));
-    DDRB &= ~(1 << MMC_DI);
-    PORTB |= ((1 << MMC_DO) | (1 << MMC_DI) | (1 << MMC_CS));
+    MMC_REG |= ((1 << MMC_DO) | (1 << MMC_CS) | (1 << MMC_CLK));
+    MMC_REG &= ~(1 << MMC_DI);
+    MMC_WRITE |= ((1 << MMC_DO) | (1 << MMC_DI) | (1 << MMC_CS));
 
     // Wartet eine kurze Zeit
     _delay_ms(20);
 
     // Initialisiere MMC/SD-Karte in den SPI-Mode
     for (i = 0; i < 250; i++) {
-        PORTB ^= (1 << MMC_CLK);
+        MMC_WRITE ^= (1 << MMC_CLK);
         _delay_us(4);
     }
-    PORTB &= ~(1 << MMC_CLK);
+    MMC_WRITE &= ~(1 << MMC_CLK);
     _delay_us(10);
-    PORTB &= ~(1 << MMC_CS);
+    MMC_WRITE &= ~(1 << MMC_CS);
     _delay_us(3);
 
     // Sendet Commando CMD0 an MMC/SD-Karte
@@ -77,7 +77,7 @@ uint8_t mmc_read_byte(void)
     uint8_t Byte = 0, j;
     for (j = 0; j < 8; j++) {
         Byte = (Byte << 1);
-        PORTB |= (1 << MMC_CLK);
+        MMC_WRITE |= (1 << MMC_CLK);
         _delay_us(4);
         if (PINB & (1 << MMC_DI)) {
             Byte |= 1;
@@ -86,7 +86,7 @@ uint8_t mmc_read_byte(void)
         else {
             Byte &= ~1;
         }
-        PORTB &= ~(1 << MMC_CLK);
+        MMC_WRITE &= ~(1 << MMC_CLK);
         _delay_us(4);
     }
     return (Byte);
@@ -100,19 +100,19 @@ void mmc_write_byte(uint8_t Byte)
     uint8_t i;
     for (i = 0; i < 8; i++) {
         if (Byte & 0x80) {
-            PORTB |= (1 << MMC_DO);
+            MMC_WRITE |= (1 << MMC_DO);
         }
 
         else {
-            PORTB &= ~(1 << MMC_DO);
+            MMC_WRITE &= ~(1 << MMC_DO);
         }
         Byte = (Byte << 1);
-        PORTB |= (1 << MMC_CLK);
+        MMC_WRITE |= (1 << MMC_CLK);
         _delay_us(4);
-        PORTB &= ~(1 << MMC_CLK);
+        MMC_WRITE &= ~(1 << MMC_CLK);
         _delay_us(4);
     }
-    PORTB |= (1 << MMC_DO);
+    MMC_WRITE |= (1 << MMC_DO);
 }
 
     // ############################################################################
diff --git a/avr/usbload/mmc.h b/avr/usbload/mmc.h
index dda4a91..629fdb9 100644
--- a/avr/usbload/mmc.h
+++ b/avr/usbload/mmc.h
@@ -4,9 +4,9 @@
 #include <avr/io.h>
 
 
-#define MMC_Write			PORTB   // Port an der die MMC/SD-Karte angeschlossen ist also des SPI
-#define MMC_Read			PINB
-#define MMC_Direction_REG	DDRB
+#define MMC_WRITE			PORTB   // Port an der die MMC/SD-Karte angeschlossen ist also des SPI
+#define MMC_READ			PINB
+#define MMC_REG	DDRB
 
 #define MMC_CS  PB4
 #define MMC_DO  PB6
@@ -23,10 +23,10 @@ extern uint8_t mmc_read_csd(uint8_t *);
 extern uint8_t mmc_read_cid(uint8_t *);
 
     // set MMC_Chip_Select to high (MMC/SD-Karte Inaktiv)
-#define MMC_Disable() MMC_Write|= (1<<MMC_CS);
+#define MMC_Disable() MMC_WRITE|= (1<<MMC_CS);
 
     // set MMC_Chip_Select to low (MMC/SD-Karte Aktiv)
-#define MMC_Enable() MMC_Write&=~(1<<MMC_CS);
+#define MMC_Enable() MMC_WRITE&=~(1<<MMC_CS);
 
 #define nop()  __asm__ __volatile__ ("nop" ::)