LF only, more FS fixes

rom/defines.s

@@ -15,13 +15,12 @@ IO_FILE_DATA          := $BC05
 IO_FILE_STATUS        := $BC07
 
 ; io commands
-IO_COMMAND_OPEN       := 1
-IO_COMMAND_CLOSE      := 2
-IO_COMMAND_SELECT_IN  := 3
-IO_COMMAND_SELECT_OUT := 4
+IO_COMMAND_OPEN_R     := 1
+IO_COMMAND_OPEN_W     := 2
+IO_COMMAND_OPEN_A     := 3
+IO_COMMAND_CLOSE      := 4
 IO_COMMAND_READ       := 5
 IO_COMMAND_WRITE      := 6
-IO_COMMAND_RESET      := 7
 
 ; io status
 FILE_STATUS_ERROR     := $01
@@ -41,5 +40,4 @@ STACK2                := STACK
 
 
 MAX_EXPON = 10
-CR = 13
 LF = 10