Index: /trunk/ccl/level-1/l1-error-system.lisp
===================================================================
--- /trunk/ccl/level-1/l1-error-system.lisp	(revision 6268)
+++ /trunk/ccl/level-1/l1-error-system.lisp	(revision 6269)
@@ -82,4 +82,11 @@
 (define-condition stack-overflow-condition (simple-storage-condition))
 
+(define-condition invalid-memory-access (storage-condition)
+  ((address :initarg :address)
+   (write-p :initform nil :initarg :write-p))
+  (:report (lambda (c s)
+             (with-slots (address write-p) c
+               (format s "Illegal memory ~a address #x~x" (if write-p "write to" "read of") address)))))
+  
 (define-condition type-error (error)
   ((datum :initarg :datum)