diff --git a/ChangeLog b/ChangeLog
index bcaade68f5..8509fe31e0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sat May 28 10:45:40 2016  SHIBATA Hiroshi  <hsbt@ruby-lang.org>
+
+	* addr2line.c: drop to support ATARI ST platform. It was discontinued
+	  more than two decades ago. [fix GH-1350] Patch by @cremno
+	* include/ruby/ruby.h: ditto.
+	* io.c: ditto.
+
 Sat May 28 10:39:47 2016  Martin Duerst  <duerst@it.aoyama.ac.jp>
 
 	* test/ruby/enc/test_case_comprehensive.rb: Converted exception for
diff --git a/addr2line.c b/addr2line.c
index b031710d71..a20e5000c4 100644
--- a/addr2line.c
+++ b/addr2line.c
@@ -36,11 +36,9 @@
 
 /* Make alloca work the best possible way.  */
 #ifdef __GNUC__
-# ifndef atarist
-#  ifndef alloca
-#   define alloca __builtin_alloca
-#  endif
-# endif	/* atarist */
+# ifndef alloca
+#  define alloca __builtin_alloca
+# endif
 #else
 # ifdef HAVE_ALLOCA_H
 #  include <alloca.h>
diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index ebb2160233..64d33434bb 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -58,11 +58,9 @@ RUBY_SYMBOL_EXPORT_BEGIN
 
 /* Make alloca work the best possible way.  */
 #ifdef __GNUC__
-# ifndef atarist
-#  ifndef alloca
-#   define alloca __builtin_alloca
-#  endif
-# endif	/* atarist */
+# ifndef alloca
+#  define alloca __builtin_alloca
+# endif
 #else
 # ifdef HAVE_ALLOCA_H
 #  include <alloca.h>
diff --git a/io.c b/io.c
index 5508ec7a2b..10cdeb699c 100644
--- a/io.c
+++ b/io.c
@@ -9297,7 +9297,7 @@ rb_io_fcntl(int argc, VALUE *argv, VALUE io)
  *  +String+ objects or +Integer+ objects. A +String+ object is passed
  *  as a pointer to the byte sequence. An +Integer+ object is passed
  *  as an integer whose bit size is same as a pointer.
- *  Up to nine parameters may be passed (14 on the Atari-ST).
+ *  Up to nine parameters may be passed.
  *
  *  The function identified by _num_ is system
  *  dependent. On some Unix systems, the numbers may be obtained from a
@@ -9321,11 +9321,7 @@ rb_io_fcntl(int argc, VALUE *argv, VALUE io)
 static VALUE
 rb_f_syscall(int argc, VALUE *argv)
 {
-#ifdef atarist
-    VALUE arg[13]; /* yes, we really need that many ! */
-#else
     VALUE arg[8];
-#endif
 #if SIZEOF_VOIDP == 8 && defined(HAVE___SYSCALL) && SIZEOF_INT != 8 /* mainly *BSD */
 # define SYSCALL __syscall
 # define NUM2SYSCALLID(x) NUM2LONG(x)
@@ -9404,32 +9400,6 @@ rb_f_syscall(int argc, VALUE *argv)
       case 8:
 	retval = SYSCALL(num, arg[0],arg[1],arg[2],arg[3],arg[4],arg[5],arg[6]);
 	break;
-#ifdef atarist
-      case 9:
-	retval = SYSCALL(num, arg[0],arg[1],arg[2],arg[3],arg[4],arg[5],arg[6],
-	  arg[7]);
-	break;
-      case 10:
-	retval = SYSCALL(num, arg[0],arg[1],arg[2],arg[3],arg[4],arg[5],arg[6],
-	  arg[7], arg[8]);
-	break;
-      case 11:
-	retval = SYSCALL(num, arg[0],arg[1],arg[2],arg[3],arg[4],arg[5],arg[6],
-	  arg[7], arg[8], arg[9]);
-	break;
-      case 12:
-	retval = SYSCALL(num, arg[0],arg[1],arg[2],arg[3],arg[4],arg[5],arg[6],
-	  arg[7], arg[8], arg[9], arg[10]);
-	break;
-      case 13:
-	retval = SYSCALL(num, arg[0],arg[1],arg[2],arg[3],arg[4],arg[5],arg[6],
-	  arg[7], arg[8], arg[9], arg[10], arg[11]);
-	break;
-      case 14:
-	retval = SYSCALL(num, arg[0],arg[1],arg[2],arg[3],arg[4],arg[5],arg[6],
-	  arg[7], arg[8], arg[9], arg[10], arg[11], arg[12]);
-        break;
-#endif
     }
 
     if (retval == -1)