diff --git a/mac/ZRTOPTBL.CPY b/mac/ZRTOPTBL.CPY
index d4ddfb20..75099e13 100644
--- a/mac/ZRTOPTBL.CPY
+++ b/mac/ZRTOPTBL.CPY
@@ -61,7 +61,6 @@ GETZ390  DS   0H
 *
 * Read record, at end set eof indicator
 GETZ390_READ   DS 0H
-         LA    R14,GETZ390_READ2       * counter z390 issue #525
          GET   Z390PRN,Z390REC         * Retrieve record
 GETZ390_READ2  DS 0H                   * Resume point after EOF
 .*       LTR   R15,R15                 * Get does not return error
@@ -128,7 +127,6 @@ GETHLASM DS   0H
 *
 * Read record, at end set eof indicator
 GETHLASM_READ   DS 0H
-         LA    R14,GETHLASM_READ2      * counter z390 issue #525
          GET   HLASMPRN,HLASMREC       * Retrieve record
 GETHLASM_READ2  DS 0H                  * Resume point after EOF
 .*       LTR   R15,R15                 * Get does not return error
@@ -217,11 +215,11 @@ COMPARE_NEXT   DS 0H                    * advance to next entry
 *
 ***********************************************************************
 Z390END  DS   0H
-         OI   Z390EOF,X'FF'            * switch eof indicator on
+         MVI  Z390EOF,X'FF'            * switch eof indicator on
          BR   R14
 
 HLASMEND DS   0H
-         OI   HLASMEOF,X'FF'           * switch eof indicator on
+         MVI  HLASMEOF,X'FF'           * switch eof indicator on
          BR   R14
 
 ***********************************************************************
@@ -231,7 +229,7 @@ HLASMEND DS   0H
 ***********************************************************************
 ERROR01  DS    0H
          WTO   'Error: Open failed',ROUTCDE=11,DESC=(6)
-         MVI   RETCODE,X'08'
+         MVI   RETCODE,8
          B     EXIT
 
 ERROR02  DS    0H
@@ -309,8 +307,8 @@ Z390REC  DS    CL(&Z390LEN)
 HLASMREC DS    CL(&HLASMLEN)
 
          DS    0D
-Z390TBL  DS    5000CL(&ENTRYLEN)       * room for 5000 opcodes
+Z390TBL  DS    (&TBLSIZE)CL(&ENTRYLEN) * room for lots of opcodes
 Z390TBL_END    EQU *-1                 * Last byte of table
          DS    0D
-HLASMTBL DS    5000CL(&ENTRYLEN)       * room for 5000 opcodes
+HLASMTBL DS    (&TBLSIZE)CL(&ENTRYLEN) * room for lots of opcodes
 HLASMTBL_END   EQU *-1                 * Last byte of table
diff --git a/rt/rt/OPCD$DOS.MLC b/rt/rt/OPCD$DOS.MLC
index 406e3a86..58c52a97 100644
--- a/rt/rt/OPCD$DOS.MLC
+++ b/rt/rt/OPCD$DOS.MLC
@@ -37,6 +37,7 @@ START    DS    0H
 * Major constants for this program
 MARKER   DC    C'Mnemonic Frmt HexOP Operands            '
 &ENTRYLEN SETA (L'MARKER)              * Marker Length = Entry Length
+&TBLSIZE  SETA 5000                    * Max nr of opcodes to expect
 &Z390LEN  SETA 256                     * Length of z390 listing record
 &HLASMLEN SETA 160                     * Length of HLASM listing record
 
diff --git a/src/az390.java b/src/az390.java
index 0c05648a..5ee7c0af 100644
--- a/src/az390.java
+++ b/src/az390.java
@@ -1982,7 +1982,7 @@ else if (tz390.op_trace_type[index]==147)
                     else if (tz390.op_name[index].equals("MVCK")
                     ||  tz390.op_name[index].equals("MVCP")
                     ||  tz390.op_name[index].equals("MVCS"))
-                       {entry=my_operands="D1(R1,B1),D2(B2),R3";                       // #500
+                       {my_operands="D1(R1,B1),D2(B2),R3";                             // #500
                         }
                     else
                        {my_operands="D1(L,B1),D2(B2)";                                 // #500
diff --git a/src/mz390.java b/src/mz390.java
index 31bb4edb..7f898bca 100644
--- a/src/mz390.java
+++ b/src/mz390.java
@@ -8494,7 +8494,7 @@ private void init_gbl_sys(){
 		add_gbl_sys("&SYSOPT_DBCS",var_setb_type); // set false indicating no DBCS support
 		add_gbl_sys("&SYSOPT_OPTABLE",var_setc_type); // "z390" opcode table name
         gbl_setc[tot_gbl_setc-1] = tz390.opt_optable; // #527
-		;	add_gbl_sys("&SYSOPT_RENT",var_setb_type); // set true if RENT option specified
+		add_gbl_sys("&SYSOPT_RENT",var_setb_type); // set true if RENT option specified
 		add_gbl_sys("&SYSOPT_XOBJECT",var_setb_type); //set true if GOFF or XOBJECT
 		add_gbl_sys("&SYSPARM",var_setc_type);
 		gbl_setc[tot_gbl_setc-1] = tz390.opt_sysparm;