Put together an example that works on A500.

examples/.gitignore

@@ -0,0 +1 @@
+hello

examples/Makefile

@@ -0,0 +1,13 @@
+CC = m68k-amigaos-gcc -noixemul -s
+CFLAGS = -Os -Wall -fomit-frame-pointer
+
+all: hello
+
+hello: LDLIBS = -lnix13
+hello: CC += -fbaserel 
+hello: CFLAGS += -m68000 -msmall-code
+hello: hello.c
+
+clean:
+	rm -f hello
+	rm -f *.o *~

examples/hello.c

@@ -0,0 +1,17 @@
+/* This example works even for Kickstart 1.3 ! */
+
+#include <proto/exec.h>
+#include <proto/dos.h>
+
+int __nocommandline = 1;
+int __initlibraries = 0;
+
+struct DosLibrary *DOSBase = NULL;
+
+int main() {
+  if ((DOSBase = (struct DosLibrary *) OpenLibrary("dos.library", 34))) {
+    Write(Output(), "Hello world!\n", 13);
+    CloseLibrary((struct Library *)DOSBase);
+  }
+  return 0;
+}