s390: New Principles of Operations is out

diff --git a/README.s390 b/README.s390
index 528eafc5ccd345759953d6825924856a2607382a..d2236d29fa861f28c06cfdf851e2f621bc498c4c 100644 (file)
--- a/README.s390
+++ b/README.s390
@@ -42,6 +42,6 @@ Reading Material
 (1) ELF ABI s390x Supplement
     https://github.com/IBM/s390x-abi/releases
 (2) z/Architecture Principles of Operation
-    https://publibfp.dhe.ibm.com/epubs/pdf/a227832d.pdf
+    https://www.ibm.com/docs/en/module_1678991624569/pdf/SA22-7832-14.pdf
 (3) Collection of z/Architecture publications
     https://linux.mainframe.blog/zarchitecture-principles-of-operation/