diff --git a/debug.c b/debug.c
index 7a75ce2..a208656 100755
--- a/debug.c
+++ b/debug.c
@@ -24,7 +24,7 @@ extern int32_t baudrate;
 extern int32_t eeprom;
 extern char *hubram;
 extern int32_t printbreak;
-extern PasmVarsT PasmVars[8];
+extern PasmVarsT PasmVars[16];
 extern SerialT serial_in;
 extern SerialT serial_out;
 
diff --git a/gdb.c b/gdb.c
index 1812762..5bd50b0 100755
--- a/gdb.c
+++ b/gdb.c
@@ -19,7 +19,7 @@
 extern FILE *logfile;
 extern FILE *tracefile;
 extern FILE *cmdfile;
-extern PasmVarsT PasmVars[8];
+extern PasmVarsT PasmVars[16];
 extern char *hubram;
 char cmd[1028];
 extern int32_t profile;
diff --git a/pasmsim.c b/pasmsim.c
index dcc0d0a..019a4a1 100755
--- a/pasmsim.c
+++ b/pasmsim.c
@@ -11,7 +11,7 @@ extern char *hubram;
 extern int32_t memsize;
 extern char lockstate[16];
 extern char lockalloc[16];
-extern PasmVarsT PasmVars[8];
+extern PasmVarsT PasmVars[16];
 extern int32_t pasmspin;
 extern int32_t cycleaccurate;
 extern int32_t loopcount;
diff --git a/pasmsim2.c b/pasmsim2.c
index 2a2c48f..554898b 100755
--- a/pasmsim2.c
+++ b/pasmsim2.c
@@ -56,12 +56,12 @@ static int wrl_flags1 = 0;
 static int rdl_flags0 = 0;
 static int rdl_flags1 = 0;
 
-char *GetOpname2(unsigned int, int *, int *, int *);
+char *GetOpname2(unsigned int, int *, int *, int *, int);
 
 static void NotImplemented(int instruction)
 {
     int dummy;
-    char *opname = GetOpname2(instruction, &dummy, &dummy, &dummy);
+    char *opname = GetOpname2(instruction, &dummy, &dummy, &dummy,0);
     printf("%s%s not implemented - %8.8x%s", NEW_LINE, opname, instruction, NEW_LINE);
     spinsim_exit(1);
 }
@@ -2641,13 +2641,13 @@ int32_t ExecutePasmInstruction2(PasmVarsT *pasmvars)
                 if (value2 >= 0xfff80 && value2 < 0xfffc0)
                     wrl_flags0 |= 1 << ((value2 >> 2) & 15);
 	        result = read_unaligned_long(value2);
-                if ((value1 & 0xff) != 0xff)
+                if (value1 & 0xff)
                     result = (result & ~0xff) | (value1 & 0xff);
-                if ((value1 & 0xff) != 0xff00)
+                if (value1 & 0xff00)
                     result = (result & ~0xff00) | (value1 & 0xff00);
-                if ((value1 & 0xff) != 0xff0000)
+                if (value1 & 0xff0000)
                     result = (result & ~0xff0000) | (value1 & 0xff0000);
-                if ((value1 & 0xff) != 0xff000000)
+                if (value1 & 0xff000000)
                     result = (result & ~0xff000000) | (value1 & 0xff000000);
 	        write_unaligned_long(value2, result);
                 if (pasmvars->printflag > 1)
@@ -3618,7 +3618,7 @@ int32_t ExecutePasmInstruction2(PasmVarsT *pasmvars)
 
                 case 43: // pop
 		pasmvars->retptr = (pasmvars->retptr - 1) & 7;
-		pasmvars->retstack[pasmvars->retptr] = value1;
+		result = pasmvars->retstack[pasmvars->retptr];
 		if (pasmvars->retptr == 7)
 		    printf("return stack underflow%s", NEW_LINE);
                 break;
diff --git a/spininterp.c b/spininterp.c
index fd0694f..5c6e94f 100755
--- a/spininterp.c
+++ b/spininterp.c
@@ -14,7 +14,7 @@
 #include "spinsim.h"
 
 extern int32_t printflag;
-extern PasmVarsT PasmVars[8];
+extern PasmVarsT PasmVars[16];
 extern char *hubram;
 extern int32_t memsize;
 extern int32_t loopcount;