diff --git a/books/bookvol10.5.pamphlet b/books/bookvol10.5.pamphlet
index 58a0132..682a139 100644
--- a/books/bookvol10.5.pamphlet
+++ b/books/bookvol10.5.pamphlet
@@ -1650,37 +1650,37 @@ a:=[[3.+4.*%i,-4.+5.*%i,5.+6.*%i,7.-8.*%i,-9.-2.*%i]]
 --E 150
 
 --S 151 of 155
-icamax(5,a,1)  -- should be 4
+icamax(5,a,1)  -- should be 3
 --R
---R   (3)  4
+--R   (3)  3
 --R                                                        Type: PositiveInteger
 --E 151
 
 --S 152 of 155
-icamax(0,a,1)  -- should be 1
+icamax(0,a,1)  -- should be 0
 --R
---R   (4)  1
---R                                                        Type: PositiveInteger
+--R   (4)  0
+--R                                                     Type: NonNegativeInteger
 --E 152
 
 --S 153 of 155
-icamax(5,a,-1) -- should be 1
+icamax(5,a,-1) -- should be 0
 --R
---R   (5)  1
---R                                                        Type: PositiveInteger
+--R   (5)  0
+--R                                                     Type: NonNegativeInteger
 --E 153
 
 --S 154 of 155
-icamax(3,a,1)  -- should be 3
+icamax(3,a,1)  -- should be 2
 --R
---R   (6)  3
+--R   (6)  2
 --R                                                        Type: PositiveInteger
 --E 154
 
 --S 155 of 155
-icamax(3,a,2)  -- should be 2 
+icamax(3,a,2)  -- should be 1 
 --R
---R   (7)  2
+--R   (7)  1
 --R                                                        Type: PositiveInteger
 --E 155
 
@@ -7706,6 +7706,9 @@ PRIMARR(COMPLEX(FLOAT)) is an array where each array element AE is
 \end{verbatim}
 so we need (caar AE) and (cadr AE) to get the real and imag parts.
 
+NOTE: Array indexing in Axiom is 0-based but Fortran is 1-based so
+the results are displaced by 1.
+
 \begin{chunk}{BLAS 1 icamax}
 (defun icamaxSpad (n zx incx)
 ; Tim Daly May 13, 2012
@@ -7719,6 +7722,7 @@ so we need (caar AE) and (cadr AE) to get the real and imag parts.
   (icamax n vec incx)))
 
 (defun icamax (n cx incx)
+; Tim Daly May 13, 2012
  (declare (type (simple-array (complex single-float) (*)) cx)
           (type fixnum incx n))
  (labels (
@@ -7727,13 +7731,13 @@ so we need (caar AE) and (cadr AE) to get the real and imag parts.
     (+ (the single-float (abs (the single-float (realpart zdum))))
        (the single-float (abs (the single-float (imagpart zdum))))))))
  (declare (ftype (function (complex single-float) single-float) cabs1))
- (let ((ix 0) (smax 0.0f0) (icamax 1) (limit (length cx)))
+ (let ((ix 0) (smax 0.0f0) (icamax 0) (limit (length cx)))
   (declare (type (single-float) smax) (type fixnum icamax ix limit))
   (when (and (> n 1) (> incx 0))
    (setf smax (the single-float (cabs1 (svref cx 0))))
    (setf ix (the fixnum (+ ix incx)))
-   (do ((i 2 (+ i 1)))
-       ((or (>= i limit) (> i n)))
+   (do ((i 1 (+ i 1)))
+       ((or (>= ix limit) (>= i n)))
      (when (> (cabs1 (the (complex single-float) (svref cx ix)))
               smax)
       (setf icamax i)
@@ -7741,6 +7745,7 @@ so we need (caar AE) and (cadr AE) to get the real and imag parts.
      (setf ix (the fixnum (+ ix incx)))))
   icamax)))
 
+
 \end{chunk}
 
 \begin{chunk}{BLAS 1 icamax lisp test}
@@ -7875,6 +7880,54 @@ c
 
 \end{chunk}
 
+\begin{chunk}{idamaxEX example}
+       program idamaxEX
+*      Tim Daly May 15, 2012
+*      unit tests for BLAS idamax
+       double precision a(5)
+       integer n
+       a = (/ 3.0, 4.0, -3.0, 5.0, -1.0 /)
+       write(6,100)a(1),a(2),a(3),a(4),a(5)
+ 100   format("a=(/ (/",f6.3," ",f6.3," ",f6.3," ",f6.3," ",f6.3," /)")
+       n=idamax(5,a,1)
+       write(6,200)n
+ 200   format("should be 4",/,"n=",i3)
+       n=idamax(3,a,1)
+       write(6,201)n
+ 201   format("should be 2",/,"n=",i3)
+       n=idamax(0,a,1)
+       write(6,202)n
+ 202   format("should be 0",/,"n=",i3)
+       n=idamax(-5,a,1)
+       write(6,203)n
+ 203   format("should be 0",/,"n=",i3)
+       n=idamax(5,a,-1)
+       write(6,204)n
+ 204   format("should be 0",/,"n=",i3)
+       n=idamax(5,a,2)
+       write(6,205)n
+ 205   format("should be 1",/,"n=",i3)
+       stop
+       end 
+\end{chunk}
+
+\begin{verbatim}
+gcc -o idamaxEX idamaxEX.f -lgfortran idamax.o && ./idamaxEX
+a=(/ (/ 3.000  4.000 -3.000  5.000 -1.000 /)
+should be 4
+n=  4
+should be 2
+n=  2
+should be 0
+n=  0
+should be 0
+n=  0
+should be 0
+n=  0
+should be 1
+n=  1
+\end{verbatim}
+
 \begin{chunk}{BLAS 1 idamax}
 (defun idamax (n dx incx)
   (declare (type (simple-array double-float (*)) dx)
diff --git a/changelog b/changelog
index 857a77d..92f8683 100644
--- a/changelog
+++ b/changelog
@@ -1,3 +1,5 @@
+20120515 tpd src/axiom-website/patches.html 20120515.01.tpd.patch
+20120515 tpd books/bookvol10.5 BLAS1 icamax 0-based fix
 20120514 tpd src/axiom-website/patches.html 20120514.01.tpd.patch
 20120514 tpd books/bookvol10.5 BLAS1 icamax
 20120508 tpd src/axiom-website/patches.html 20120508.01.tpd.patch
diff --git a/src/axiom-website/patches.html b/src/axiom-website/patches.html
index eac4a1a..3f9a0f2 100644
--- a/src/axiom-website/patches.html
+++ b/src/axiom-website/patches.html
@@ -3914,5 +3914,7 @@ books/bookvol10.5 BLAS1 dzasum<br/>
 books/bookvol10.5 BLAS1 dznrm2<br/>
 <a href="patches/20120514.01.tpd.patch">20120514.01.tpd.patch</a>
 books/bookvol10.5 BLAS1 icamax<br/>
+<a href="patches/20120515.01.tpd.patch">20120515.01.tpd.patch</a>
+books/bookvol10.5 BLAS1 icamax 0-based fix<br/>
  </body>
 </html>