diff --git a/src/ikarus.boot b/src/ikarus.boot
index 61ac11d..e4cecfd 100644
Binary files a/src/ikarus.boot and b/src/ikarus.boot differ
diff --git a/src/ikarus.bytevectors.ss b/src/ikarus.bytevectors.ss
index c45d41d..fd2a184 100644
--- a/src/ikarus.bytevectors.ss
+++ b/src/ikarus.bytevectors.ss
@@ -3,13 +3,17 @@
   (export make-bytevector bytevector-length bytevector-s8-ref
           bytevector-u8-ref bytevector-u8-set! bytevector-s8-set!
           bytevector-copy! u8-list->bytevector bytevector->u8-list
-          bytevector-fill! bytevector-copy bytevector=?)
+          bytevector-fill! bytevector-copy bytevector=?
+          bytevector-uint-ref bytevector-sint-ref 
+          bytevector->uint-list bytevector->sint-list)
   (import 
     (except (ikarus) 
         make-bytevector bytevector-length bytevector-s8-ref
         bytevector-u8-ref bytevector-u8-set! bytevector-s8-set! 
         bytevector-copy! u8-list->bytevector bytevector->u8-list
-        bytevector-fill! bytevector-copy bytevector=?)
+        bytevector-fill! bytevector-copy bytevector=?
+        bytevector-uint-ref bytevector-sint-ref
+        bytevector->uint-list bytevector->sint-list)
     (ikarus system $fx)
     (ikarus system $pairs)
     (ikarus system $bytevectors))
@@ -191,6 +195,154 @@
              ($bytevector-set! dst di ($bytevector-u8-ref src si))
              (f src ($fxadd1 si) dst ($fxadd1 di) sj)))])))
 
+  (module (bytevector-uint-ref bytevector-sint-ref
+           bytevector->uint-list bytevector->sint-list)
+    (define (uref-big x ib il) ;; ib included, il excluded
+      (cond
+        [($fx= il ib) 0]
+        [else
+         (let ([b ($bytevector-u8-ref x ib)])
+           (cond
+             [($fx= b 0) (uref-big x ($fxadd1 ib) il)]
+             [else
+              (case ($fx- il ib)
+                [(1) b]
+                [(2) ($fx+ ($fxsll b 8)
+                           ($bytevector-u8-ref x ($fxsub1 il)))]
+                [(3) 
+                 ($fx+ ($fxsll ($fx+ ($fxsll b 8)
+                                     ($bytevector-u8-ref x ($fxadd1 ib)))
+                               8)
+                       ($bytevector-u8-ref x ($fxsub1 il)))]
+                [else
+                 (let ([im ($fxsra ($fx+ il ib) 1)])
+                   (+ (uref-big x im il)
+                      (* (uref-big x ib im)
+                         (expt 256 ($fx- il im)))))])]))]))
+    (define (uref-little x il ib) ;; il included, ib excluded
+      (cond
+        [($fx= il ib) 0]
+        [else
+         (let ([ib^ ($fxsub1 ib)])
+          (let ([b ($bytevector-u8-ref x ib^)])
+            (cond
+              [($fx= b 0) (uref-little x il ib^)]
+              [else
+               (case ($fx- ib il)
+                 [(1) b]
+                 [(2) ($fx+ ($fxsll b 8) ($bytevector-u8-ref x il))]
+                 [(3) 
+                  ($fx+ ($fxsll ($fx+ ($fxsll b 8) 
+                                      ($bytevector-u8-ref x ($fxadd1 il)))
+                                8)
+                        ($bytevector-u8-ref x il))]
+                 [else
+                  (let ([im ($fxsra ($fx+ il ib) 1)])
+                    (+ (uref-little x il im) 
+                       (* (uref-little x im ib) 
+                          (expt 256 ($fx- im il)))))])])))]))
+    (define (sref-big x ib il) ;; ib included, il excluded
+      (cond
+        [($fx= il ib) -1]
+        [else
+         (let ([b ($bytevector-u8-ref x ib)])
+           (cond
+             [($fx= b 0) (uref-big x ($fxadd1 ib) il)]
+             [($fx= b 255) (sref-big-neg x ($fxadd1 ib) il)]
+             [($fx< b 128) (uref-big x ib il)]
+             [else (- (uref-big x ib il) (expt 256 ($fx- il ib)))]))]))
+    (define (sref-big-neg x ib il) ;; ib included, il excluded
+      (cond
+        [($fx= il ib) -1]
+        [else
+         (let ([b ($bytevector-u8-ref x ib)])
+           (cond
+             [($fx= b 255) (sref-big-neg x ($fxadd1 ib) il)]
+             [else (- (uref-big x ib il) (expt 256 ($fx- il ib)))]))]))
+    (define (sref-little x il ib) ;; il included, ib excluded
+      (cond
+        [($fx= il ib) -1]
+        [else
+         (let ([ib^ ($fxsub1 ib)])
+          (let ([b ($bytevector-u8-ref x ib^)])
+            (cond
+              [($fx= b 0) (uref-little x il ib^)]
+              [($fx= b 255) (sref-little-neg x il ib^)]
+              [($fx< b 128) (uref-little x il ib)]
+              [else (- (uref-little x il ib) (expt 256 ($fx- ib il)))])))]))
+    (define (sref-little-neg x il ib) ;; il included, ib excluded
+      (cond
+        [($fx= il ib) -1]
+        [else
+         (let ([ib^ ($fxsub1 ib)])
+          (let ([b ($bytevector-u8-ref x ib^)])
+            (cond
+              [($fx= b 255) (sref-little-neg x il ib^)]
+              [else (- (uref-little x il ib) (expt 256 ($fx- ib il)))])))])) 
+    (define bytevector-sint-ref
+      (lambda (x k endianness size)
+        (define who 'bytevector-sint-ref)
+        (unless (bytevector? x) (error who "~s is not a bytevector" x))
+        (unless (and (fixnum? k) ($fx>= k 0)) (error who "invalid index ~s" k))
+        (unless (and (fixnum? size) ($fx>= size 1)) (error who "invalid size ~s" size))
+        (let ([n ($bytevector-length x)])
+          (unless ($fx< k n) (error who "index ~s is out of range" k))
+          (let ([end ($fx+ k size)])
+            (unless (and ($fx>= end 0) ($fx<= end n))
+              (error who "~s+~s is out of range" k size))
+            (case endianness
+              [(little) (sref-little x k end)]
+              [(big)    (sref-big x k end)]
+              [else (error who "invalid endianness ~s" endianness)])))))
+    (define bytevector-uint-ref
+      (lambda (x k endianness size)
+        (define who 'bytevector-uint-ref)
+        (unless (bytevector? x) (error who "~s is not a bytevector" x))
+        (unless (and (fixnum? k) ($fx>= k 0)) (error who "invalid index ~s" k))
+        (unless (and (fixnum? size) ($fx>= size 1)) (error who "invalid size ~s" size))
+        (let ([n ($bytevector-length x)])
+          (unless ($fx< k n) (error who "index ~s is out of range" k))
+          (let ([end ($fx+ k size)])
+            (unless (and ($fx>= end 0) ($fx<= end n))
+              (error who "~s+~s is out of range" k size))
+            (case endianness
+              [(little) (uref-little x k end)]
+              [(big)    (uref-big x k end)]
+              [else (error who "invalid endianness ~s" endianness)])))))
+    (define (bytevector->some-list x k n ls proc who)
+      (cond
+        [($fx= n 0) ls]
+        [else
+         (let ([i ($fx- n k)])
+           (cond
+             [($fx>= i 0)
+              (bytevector->some-list x k i (cons (proc x i n) ls) proc who)]
+             [else
+              (error who "invalid size ~s" k)]))]))
+    (define bytevector->uint-list
+      (lambda (x endianness size)
+        (define who 'bytevector->uint-list)
+        (unless (bytevector? x) (error who "~s is not a bytevector" x))
+        (unless (and (fixnum? size) ($fx>= size 1)) (error who "invalid size ~s" size))
+        (case endianness
+          [(little) (bytevector->some-list x size ($bytevector-length x)
+                      '() uref-little 'bytevector->uint-list)]
+          [(big)    (bytevector->some-list x size ($bytevector-length x) 
+                      '() uref-big 'bytevector->uint-list)]
+          [else (error who "invalid endianness ~s" endianness)])))
+    (define bytevector->sint-list
+      (lambda (x endianness size)
+        (define who 'bytevector->sint-list)
+        (unless (bytevector? x) (error who "~s is not a bytevector" x))
+        (unless (and (fixnum? size) ($fx>= size 1)) (error who "invalid size ~s" size))
+        (case endianness
+          [(little) (bytevector->some-list x size ($bytevector-length x)
+                      '() sref-little 'bytevector->sint-list)]
+          [(big)    (bytevector->some-list x size ($bytevector-length x) 
+                      '() sref-big 'bytevector->sint-list)]
+          [else (error who "invalid endianness ~s" endianness)])))
+    )
+
 
 
   )
diff --git a/src/ikarus.numerics.ss b/src/ikarus.numerics.ss
index f44a5fc..b4c17fb 100644
--- a/src/ikarus.numerics.ss
+++ b/src/ikarus.numerics.ss
@@ -23,7 +23,7 @@
 
 (library (ikarus generic-arithmetic)
   (export + - * zero? = < <= > >= add1 sub1 quotient remainder
-          positive?
+          positive? expt
           quotient+remainder number->string string->number)
   (import 
     (ikarus system $fx)
@@ -31,7 +31,7 @@
     (ikarus system $strings)
     (except (ikarus) + - * zero? = < <= > >= add1 sub1 quotient
             remainder quotient+remainder number->string positive?
-            string->number))
+            string->number expt))
 
   (define (fixnum->flonum x)
     (foreign-call "ikrt_fixnum_to_flonum" x))
diff --git a/src/makefile.ss b/src/makefile.ss
index cfde1b5..c2d44c4 100755
--- a/src/makefile.ss
+++ b/src/makefile.ss
@@ -283,6 +283,10 @@
     [bytevector-copy         i]
     [bytevector-fill!        i]
     [bytevector=?            i]
+    [bytevector-uint-ref     i]
+    [bytevector-sint-ref     i]
+    [bytevector->uint-list   i]
+    [bytevector->sint-list   i]
 
     [for-each                i r]
     [map                     i r]
@@ -322,6 +326,7 @@
     [+                       i r]
     [add1                    i]
     [sub1                    i]
+    [expt                    i]
     [number?                 i r]
     [bignum?                 i]
     [integer?                i]
diff --git a/src/tests/bytevectors.ss b/src/tests/bytevectors.ss
index 5033b73..5f14b1e 100644
--- a/src/tests/bytevectors.ss
+++ b/src/tests/bytevectors.ss
@@ -34,12 +34,57 @@
          (bytevector-u8-ref b 0)
          (bytevector-s8-ref b 1)
          (bytevector-u8-ref b 1)))]
-
     [(lambda (x) (equal? x '(1 2 3 1 2 3 4 8)))
      (let ([b (u8-list->bytevector '(1 2 3 4 5 6 7 8))])
        (bytevector-copy! b 0 b 3 4)
        (bytevector->u8-list b))]
-
+    [(lambda (x) (= x 17)) 
+     (bytevector-uint-ref 
+       (u8-list->bytevector '(17))
+       0 'little 1)]
+    [(lambda (x) (= x 17)) 
+     (bytevector-uint-ref 
+       (u8-list->bytevector '(17))
+       0 'big 1)]
+    [(lambda (x) (= x (+ 17 (* 54 256))))
+     (bytevector-uint-ref 
+       (u8-list->bytevector '(17 54))
+       0 'little 2)]
+    [(lambda (x) (= x (+ 17 (* 54 256))))
+     (bytevector-uint-ref 
+       (u8-list->bytevector (reverse '(17 54)))
+       0 'big 2)] 
+    [(lambda (x) (= x (+ 17 (* 54 256) (* 98 256 256))))
+     (bytevector-uint-ref 
+       (u8-list->bytevector '(17 54 98))
+       0 'little 3)]
+    [(lambda (x) (= x (+ 17 (* 54 256) (* 98 256 256))))
+     (bytevector-uint-ref 
+       (u8-list->bytevector (reverse '(17 54 98)))
+       0 'big 3)] 
+    [(lambda (x) (= x (+ 17 (* 54 256) (* 98 256 256) (* 120 256 256 256))))
+     (bytevector-uint-ref 
+       (u8-list->bytevector '(17 54 98 120))
+       0 'little 4)]
+    [(lambda (x) (= x #x123897348738947983174893204982390489))
+     (bytevector-uint-ref 
+       (u8-list->bytevector
+         '(#x89 #x04 #x39 #x82 #x49 #x20 #x93 #x48 #x17
+           #x83 #x79 #x94 #x38 #x87 #x34 #x97 #x38 #x12))
+       0 'little 18)]
+    [(lambda (x) (= x #x123897348738947983174893204982390489))
+     (bytevector-uint-ref 
+       (u8-list->bytevector
+         (reverse
+           '(#x89 #x04 #x39 #x82 #x49 #x20 #x93 #x48 #x17
+             #x83 #x79 #x94 #x38 #x87 #x34 #x97 #x38 #x12)))
+       0 'big 18)]
+    [(lambda (x) (equal? x '(513 65283 513 513)))
+     (let ([b (u8-list->bytevector '(1 2 3 255 1 2 1 2))])
+       (bytevector->uint-list b 'little 2))]
+    [(lambda (x) (equal? x '(513 -253 513 513)))
+     (let ([b (u8-list->bytevector '(1 2 3 255 1 2 1 2))])
+       (bytevector->sint-list b 'little 2))]
     ))