diff --git a/unix/lang/config.h b/unix/lang/config.h
index b926671..69a1d8b 100644
--- a/unix/lang/config.h
+++ b/unix/lang/config.h
@@ -2,7 +2,7 @@
 /* config.h.in.  Generated from configure.ac by autoheader.  */
 
 /* build-time, that will be displayed in banner */
-#define BUILD_TIME "Mon Dec 23 05:16:37 UTC 2024"
+#define BUILD_TIME "Sat Dec 28 11:34:58 UTC 2024"
 
 /* Define to 1 if using 'alloca.c'. */
 /* #undef C_ALLOCA */
diff --git a/unix/lang/config.status b/unix/lang/config.status
index d80c426..8c67475 100755
--- a/unix/lang/config.status
+++ b/unix/lang/config.status
@@ -423,7 +423,7 @@ $config_commands
 
 Report bugs to the package provider."
 
-ac_cs_config=''
+ac_cs_config=''\''CFLAGS=-g -O2'\'''
 ac_cs_version="\
 yabasic config.status 2.90.5
 configured by ./configure, generated by GNU Autoconf 2.72,
@@ -515,7 +515,7 @@ if $ac_cs_silent; then
 fi
 
 if $ac_cs_recheck; then
-  set X /bin/bash './configure'  $ac_configure_extra_args --no-create --no-recursion
+  set X /bin/bash './configure'  'CFLAGS=-g -O2' $ac_configure_extra_args --no-create --no-recursion
   shift
   \printf "%s\n" "running CONFIG_SHELL=/bin/bash $*" >&6
   CONFIG_SHELL='/bin/bash'
@@ -1018,7 +1018,7 @@ D["HAVE_CURSES_H"]=" 1"
 D["HAVE_NCURSES_H"]=" 1"
 D["HAVE_GETNSTR"]=" 1"
 D["UNIX_ARCHITECTURE"]=" \"x86_64-unknown-linux-gnu\""
-D["BUILD_TIME"]=" \"Mon Dec 23 05:16:37 UTC 2024\""
+D["BUILD_TIME"]=" \"Sat Dec 28 11:34:58 UTC 2024\""
   for (key in D) D_is_set[key] = 1
   FS = ""
 }
diff --git a/unix/lang/study/README.org b/unix/lang/study/README.org
index 3c9c6b8..71c0f6c 100644
--- a/unix/lang/study/README.org
+++ b/unix/lang/study/README.org
@@ -1 +1 @@
-Some (yabasic-) programs to investigate various issues.
+Some yabasic-programs to study new features and old issues.
diff --git a/unix/lang/study/colors.yab b/unix/lang/study/colors.yab
index 1ec0a33..2659a63 100755
--- a/unix/lang/study/colors.yab
+++ b/unix/lang/study/colors.yab
@@ -1,5 +1,6 @@
 clear screen
+error "foo"
 dim cols$(7)
 for i=0 to 7:read cols$(i):next i
-for i=0 to 7:for j=0 to 7:print color(cols$(i),cols$(j)) ">>> " + cols$(i) + cols$(j) + " <<<";:next j:next i
+for i=0 to 7:for j=0 to 7:print color(cols$(i),cols$(j)) ">>> fg=" + cols$(i) + ", bg=" + cols$(j) + " <<<";:next j:next i
 data "white","red", "blue", "green", "yellow", "cyan", "magenta", "black"
\ No newline at end of file
diff --git a/unix/lang/study/notes.org b/unix/lang/study/notes.org
new file mode 100644
index 0000000..b040053
--- /dev/null
+++ b/unix/lang/study/notes.org
@@ -0,0 +1,30 @@
+All sorts of temporary notes related to studies in yabasic; not ment to be readable by
+themselves; might even be in german
+
+* [2024-12-28 Sat] Error messages after curinit() should switch of curses first
+
+  Code looks right, behaviour not.
+
+  Puzzling:
+
+  - Artifical error "thud" in initcol
+  - Some sleeps to make sequence of things easier visible 
+  - Should trigger printf in this sequence (according to code):
+    - foo0, foo1, foo2 in error_with_position
+    - qux0, qux1 in show_and_mark_line
+  - However the sequence on screen is:
+    - foo0 in curses
+    - qux0, qux1 out of curses
+    - foo1, foo2 out of curses
+  - Maybe threading-error ? Which threads ?
+
+
+  ./configure CFLAGS="-g -O0" && make
+
+  gdb setup:
+
+  break main.c:2055
+  break main.c:1961
+  tty /dev/pts/3
+  run study/colors.yab
+