Merge branch 'master' of animus.robocracy.org:/srv/git/knowledge

1 files changed, 14 insertions, 2 deletions

diff --git a/software/idl.page b/software/idl.page
index e961a71..00b444a 100644
--- a/software/idl.page
+++ b/software/idl.page
@@ -16,8 +16,9 @@ Language Design
 
 IDL is "pass by reference", which means that arguments to functions are always
 variable pointers, not the actual value (the alternative is usually to pass by
-copy, where the value gets passed through to a new variable inside the function.One side effect of this is that return values are collected by passing a
-recieving variable name as an argument to functions.
+copy, where the value gets passed through to a new variable inside the
+function. One side effect of this is that return values are collected by
+passing a recieving variable name as an argument to functions.
 
 Syntax
 -----------------
@@ -30,4 +31,15 @@ Command Interface
 
 Instead of the ever-standard ``!`` to execute system commands, use ``$``.
 
+X Windows
+--------------
+When used remotely with X Windows, sometimes plots don't refresh correctly
+(eg, blacked out after another window has covered them). To correct this issue,
+add these lines to your ``~/.Xdefaults``::
 
+    !stuff to manage IDL under 24-bit Linux displays
+    idl.retain:2
+    idl.gr_visual: TrueColor
+
+and then run ``xrdb -merge ~/.Xdefault``. (This tip from 
+http://star.pst.qub.ac.uk/help/idl.shtml)