diff --git a/analyzer/user_interface.cpp b/analyzer/user_interface.cpp
index e51b206..29c0f93 100644
--- a/analyzer/user_interface.cpp
+++ b/analyzer/user_interface.cpp
@@ -3,6 +3,9 @@
  *       hei_user_interface.hpp
  */
 
+#include <stdarg.h>
+#include <stdio.h>
+
 #include <hei_user_interface.hpp>
 
 namespace libhei
@@ -10,34 +13,58 @@
 
 //------------------------------------------------------------------------------
 
-ReturnCode registerRead(const Chip& i_chip, void* o_buffer, size_t& io_bufSize,
-                        uint64_t i_regType, uint64_t i_address)
+bool registerRead(const Chip& i_chip, void* o_buffer, size_t& io_bufSize,
+                  uint64_t i_regType, uint64_t i_address)
 {
-    ReturnCode rc = RC_SUCCESS;
+    bool accessFailure = false;
 
     //    HEI_INF("registerRead(%p,%p,%lx,%lx,%lx)", i_chip.getChip(),
     //             o_buffer, io_bufSize, i_regType, i_address);
 
-    return rc;
+    return accessFailure;
 }
 
 //------------------------------------------------------------------------------
 
 #ifndef __HEI_READ_ONLY
 
-ReturnCode registerWrite(const Chip& i_chip, void* i_buffer, size_t& io_bufSize,
-                         uint64_t i_regType, uint64_t i_address)
+bool registerWrite(const Chip& i_chip, void* i_buffer, size_t& io_bufSize,
+                   uint64_t i_regType, uint64_t i_address)
 {
-    ReturnCode rc = RC_SUCCESS;
+    bool accessFailure = false;
 
     //    HEI_INF("registerWrite(%p,%p,%lx,%lx,%lx)", i_chip.getChip(),
     //             i_buffer, io_bufSize, i_regType, i_address);
 
-    return rc;
+    return accessFailure;
 }
 
 #endif
 
 //------------------------------------------------------------------------------
 
+// prints a single line to stdout
+void hei_inf(char* format, ...)
+{
+    va_list args;
+    fprintf(stdout, "I> ");
+    va_start(args, format);
+    vfprintf(stdout, format, args);
+    va_end(args);
+    fprintf(stdout, "\n");
+}
+
+//------------------------------------------------------------------------------
+
+// prints a single line to stderr
+void hei_err(char* format, ...)
+{
+    va_list args;
+    fprintf(stderr, "E> ");
+    va_start(args, format);
+    vfprintf(stderr, format, args);
+    va_end(args);
+    fprintf(stderr, "\n");
+}
+
 } // namespace libhei