diff --git a/vimlac/log.c b/vimlac/log.c
new file mode 100644
index 0000000..938dfda
--- /dev/null
+++ b/vimlac/log.c
@@ -0,0 +1,33 @@
+/*
+ * Log routines for the imlac simulator.
+ */
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+
+char *LogFile = "vimlac.log";
+char *LogPrefix = "";
+
+
+/******************************************************************************
+Description : printf()-style log routine.
+ Parameters : like printf()
+    Returns : 
+   Comments : 
+ ******************************************************************************/
+void
+vlog(char *fmt, ...)
+{
+    va_list ap;
+    char    buff[1024];
+    FILE    *fd;
+
+    va_start(ap, fmt);
+    vsprintf(buff, fmt, ap);
+    fd = fopen(LogFile, "a");
+    fprintf(fd, "%s: %s\n", LogPrefix, buff);
+    fclose(fd);
+    va_end(ap);
+}
diff --git a/vimlac/log.h b/vimlac/log.h
new file mode 100644
index 0000000..5926039
--- /dev/null
+++ b/vimlac/log.h
@@ -0,0 +1,11 @@
+/*
+ * Log routines for the imlac simulation.
+ */
+
+#ifndef LOG_H
+#define LOG_H
+
+void vlog(char *fmt, ...);
+extern char *LogPrefix;
+
+#endif