more compatible tape buffer handling

c64/aliases/,aliases_config.s

@@ -114,6 +114,10 @@
 
 // Check that I/O configuration is correct
 {
+#if CONFIG_RS232_UP9600 && (CONFIG_TAPE_NORMAL || CONFIG_TAPE_TURBO)
+	.error "CONFIG_RS232_UP9600 is not compatible with CONFIG_TAPE_*"
+#endif
+
 #if CONFIG_IEC_JIFFYDOS && !CONFIG_IEC
 	.error "CONFIG_IEC_JIFFYDOS requires CONFIG_IEC"
 #endif

c64/aliases/,aliases_ram_lowmem.s

@@ -281,8 +281,9 @@
 
 	//                 $314     $334-$33B  -- UNUSED --          free for user software
 	
+#if !CONFIG_RS232_UP9600
 	.label TBUFFR    = $33C  // $33C-$3FB  [!] tape buffer, our usage details differ
-#if CONFIG_RS232_UP9600
+#else
     .label REVTAB    = $37C  // $37C-$3FB  -- WIP -- [!] RS-232 precalculated data
 #endif