started unification of floppy and ramdisk code

Makefile

@@ -68,7 +68,7 @@ SRCDIR_DOS_M65 = $(SRCDIR_COMMON) \
                  src/dos_m65/filesystem_vfs \
                  src/dos_m65/lowlevel \
                  src/dos_m65/pseudoiec \
-                 src/dos_m65/unit_floppy \
+                 src/dos_m65/unit_disk \
                  src/dos_m65/unit_ramdisk \
                  src/dos_m65/unit_sdcard \
                  src/dos_m65/utils

src/dos_m65/unit_ramdisk/unit_rd_cmd_close.s

@@ -3,6 +3,8 @@
 ; Close currently opened file
 ;
 
+; XXX to be unified with floppy code
+
 
 unit_rd_cmd_CLOSE:
 

src/dos_m65/unit_ramdisk/unit_rd_cmd_open.s

@@ -3,6 +3,8 @@
 ; Open file for reading
 ;
 
+; XXX to be unified with floppy code
+
 
 unit_rd_cmd_OPEN:
 

src/dos_m65/unit_ramdisk/unit_rd_cmd_read.s

@@ -3,6 +3,8 @@
 ; Read more data into the buffer
 ;
 
+; XXX to be unified with floppy code
+
 
 unit_rd_cmd_READ: