case 0x3: // st rs, o(rd) .......... 3spd  (p = o / 4)
          mem.writeInteger(4 * insOp1.get() + reg.get(insOp2.get()), reg.get(insOp0.get()));
        break;
      case 0x4: // st rs, (rd, ri, 4) .... 4sdi
        mem.writeInteger(reg.get(insOp1.get()) + 4 * reg.get(insOp2.get()), reg.get(insOp0.get()));
        break;