diff --git a/ChangeLog.csl b/ChangeLog.csl
index 1ace422..c07e1ce 100644
--- a/ChangeLog.csl
+++ b/ChangeLog.csl
@@ -1,3 +1,11 @@
+2006-04-18  Mark Mitchell  <mark@codesourcery.com>
+
+	Issue #655
+	* gdb/mt-tdep.c (mt_gdb_regnums): Add ZI2, ZQ2, Ichannel2,
+	Iscramb2, Qscramb2, Qchannel2.
+	(mt_register_name): Likewise.
+	(mt_copro_register_type): Describe ZI2 and ZQ2.
+	
 2006-04-11  Mark Mitchell  <mark@codesourcery.com>
 
 	Issue #658
diff --git a/gdb/mt-tdep.c b/gdb/mt-tdep.c
index 3b158ae..da77bd8 100644
--- a/gdb/mt-tdep.c
+++ b/gdb/mt-tdep.c
@@ -109,6 +109,12 @@
   MT_OUT_REGNUM,			/* 16 bits.  */
   MT_EXMAC_REGNUM,		/* 32 bits (8 used).  */
   MT_QCHANNEL_REGNUM,		/* 32 bits.  */
+  MT_ZI2_REGNUM,                /* 16 bits.  */
+  MT_ZQ2_REGNUM,                /* 16 bits.  */
+  MT_CHANNEL2_REGNUM,           /* 32 bits.  */
+  MT_ISCRAMB2_REGNUM,           /* 32 bits.  */
+  MT_QSCRAMB2_REGNUM,           /* 32 bits.  */
+  MT_QCHANNEL2_REGNUM,          /* 32 bits.  */
 
   /* Number of real registers.  */
   MT_NUM_REGS,
@@ -149,6 +155,7 @@
     "cr8", "cr9", "cr10", "cr11", "cr12", "cr13", "cr14", "cr15",
     "bypa", "bypb", "bypc", "flag", "context", "" /* mac.  */ , "z1", "z2",
     "Ichannel", "Iscramb", "Qscramb", "out", "" /* ex-mac.  */ , "Qchannel",
+    "zi2", "zq2", "Ichannel2", "Iscramb2", "Qscramb2", "Qchannel2",
     /* Pseudo-registers.  */
     "coprocessor", "MAC"
   };
@@ -213,6 +220,8 @@
     case MT_Z1_REGNUM:
     case MT_Z2_REGNUM:
     case MT_OUT_REGNUM:
+    case MT_ZI2_REGNUM:
+    case MT_ZQ2_REGNUM:
       return builtin_type_int16;
     case MT_EXMAC_REGNUM:
     case MT_MAC_REGNUM: