diff --git a/HP2100/hp2100_defs.h b/HP2100/hp2100_defs.h
index 24dd613b..9ee83e32 100644
--- a/HP2100/hp2100_defs.h
+++ b/HP2100/hp2100_defs.h
@@ -23,7 +23,9 @@
    be used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from Robert M Supnik.
 
-   09-May-12    JDB     Added pragmas to suppress logical operator precedence warnings
+   12-May-12    JDB     Added pragmas to suppress logical operator precedence warnings
+   12-Feb-12    JDB     Added MA device select code assignment
+                        Added ma_boot_ext() declaration
    10-Feb-12    JDB     Added hp_setsc, hp_showsc functions to support SC modifier
    28-Mar-11    JDB     Tidied up signal handling
    29-Oct-10    JDB     DMA channels renamed from 0,1 to 1,2 to match documentation
@@ -73,10 +75,11 @@
 #include "sim_defs.h"                                   /* simulator defns */
 
 
-/* Required to quell Mark's Mystery Compiler's precedence warnings */
+/* Required to quell clang precedence warnings */
 
 #if defined (__GNUC__)
 #pragma GCC diagnostic ignored "-Wunknown-pragmas"
+#pragma GCC diagnostic ignored "-Wpragmas"
 #pragma GCC diagnostic ignored "-Wlogical-op-parentheses"
 #endif
 
@@ -183,6 +186,7 @@ typedef enum { INITIAL, SERVICE } POLLMODE;             /* poll synchronization
 #define MUXC            042                             /* 12920A control */
 #define DI_DA           043                             /* 12821A Disc Interface with Amigo disc devices */
 #define DI_DC           044                             /* 12821A Disc Interface with CS/80 disc and tape devices */
+#define DI_MA           045                             /* 12821A Disc Interface with Amigo mag tape devices */
 
 #define OPTDEV          002                             /* start of optional devices */
 #define CRSDEV          006                             /* start of devices that receive CRS */
@@ -473,6 +477,7 @@ extern t_stat      hp_showdev (FILE *st, UNIT *uptr, int32 val, void *desc);
 
 /* Device-specific functions */
 
-extern int32 sync_poll (POLLMODE poll_mode);
+extern int32  sync_poll   (POLLMODE poll_mode);
+extern t_stat ma_boot_ext (uint32 SR);
 
 #endif