diff --git a/IBM360/ibm360_cpu.c b/IBM360/ibm360_cpu.c
index a49dd99..d2d5f88 100644
--- a/IBM360/ibm360_cpu.c
+++ b/IBM360/ibm360_cpu.c
@@ -573,7 +573,7 @@ int  TransAddr(uint32 va, uint32 *pa) {
      } else {
          addr = (entry >> 28) + 1;
          /* Check if entry valid and in correct length */
-         if (entry & PTE_VALID || (page >> pte_len_shift) > addr) {
+         if (entry & PTE_VALID || (page >> pte_len_shift) >= addr) {
              M[0x90 >> 2] = va;
              key[0] |= 0x6;
              PC = iPC;
@@ -2375,7 +2375,7 @@ save_dbl:
                     if ((cpu_unit[0].flags & FEAT_370) != 0) {
                         addr2 = (entry >> 28) + 1;
                         /* Check if over end of table */
-                        if ((page >> pte_len_shift) > addr2) {
+                        if ((page >> pte_len_shift) >= addr2) {
                             cc = 3;
                             regs[reg1] = addr1;
                             per_mod |= 1 << reg1;
@@ -3460,17 +3460,14 @@ save_dbl:
                    src2 = regs[R2(reg)|1];
                    fill = (src2 >> 24) & 0xff;
                    src2 &= AMASK;
-                   dest = addr2 + src2;
-                   desth = addr1 + src1;
-                   if ((dest & ~AMASK) != 0) { /* Wrap around */
-                      if (addr2 > desth || desth <= addr1) {
-                         cc = 3;
-                         break;
-                      }
-                   } else {
-                      if (desth < dest && addr1 >= addr2) {
-                         cc = 3;
-                         break;
+
+                   if (src1 > 1 && src2 > 1) {
+                      dest = addr2 + ((src2 < src1) ? src2 : src1) - 1;
+                      dest &= AMASK;
+                      if ((dest > addr2 && (addr1 > addr2 && addr1 <= dest)) ||
+                          (dest <= addr2 && (addr1 > addr1 || addr1 <= dest))) {
+                          cc = 3;
+                          break;
                       }
                    }
                    if (src1 == 0)