OPUS20: Specify requirements more precisely in README

diff --git a/LUFFT_OPUS20/README.md b/LUFFT_OPUS20/README.md
index 85c579b4b3ef30748484485fcfa9ee5b8f5ce14b..fd3d2583a0aeba442f6afc69fcbc050b03174343 100644 (file)
--- a/LUFFT_OPUS20/README.md
+++ b/LUFFT_OPUS20/README.md
@@ -2,11 +2,21 @@
 
 ### Installation / Requirements
 
-    pip install --upgrade -r requirements.txt
+For this to work, you need some requirements as mentioned
+[here](https://pcaspy.readthedocs.io/en/latest/installation.html):
+
+* Python 2.6+ including 3.x
+* Python headers (package name "python-dev" or similar)
+* SWIG 1.3.29+ (package name "swig")
+* readline library (package name "libreadline-dev")
+
+Once, the prerequisits are met, run:
+
+    pip3 install -r requirements.txt --upgrade --user
 
 ### Starting
 
-    $ ./lufft_opus20_ioc.py -h
+    $ python3 ./lufft_opus20_ioc.py -h
     usage: lufft_opus20_ioc.py [-h] --sys SYS --sub SUB --esys ESYS
                                opus20_hostname