-#define FDC_ADDRESS_LEN 8 // read 8 address bits\r
-#define FDC_COMMAND_OFFSET 24 // skip 24 bits (8 address bits + 12 status bits + 4 repeat bits)\r
-#define FDC_COMMAND_LEN 8 // read 8 bits\r
+#define FDC_ADDRESS_LEN 14 // read 14 address bits, but use only 6, shift 8 into command\r
+#define FDC_COMMAND_OFFSET 20 // skip 20 bits\r
+#define FDC_COMMAND_LEN 12 // read 12 bits\r