Applied upstream patches (adds IBM PS/2 M70.)

Fixed two small bugs.
Moved the MRTHOR back to mainline.
Fixed a bug in the Tosh 1000.

src/mem.h

@@ -8,7 +8,7 @@
  *
  *		Definitions for the memory interface.
  *
- * Version:	@(#)mem.h	1.0.1	2018/02/14
+ * Version:	@(#)mem.h	1.0.2	2018/03/12
  *
  * Authors:	Fred N. van Kempen, <decwiz@yahoo.com>
  *		Sarah Walker, <tommowalker@tommowalker.co.uk>
@@ -101,6 +101,8 @@ typedef struct mem_mapping_t
 #define MEM_MAPPING_EXTERNAL 1
 /*Only present on internal bus (RAM)*/
 #define MEM_MAPPING_INTERNAL 2
+/*Executing from ROM may involve additional wait states*/
+#define MEM_MAPPING_ROM      4
 
 extern uint8_t *ram,*rom;
 extern uint8_t romext[32768];