dir seeking

libsrc/rp6502/f_seekdir.c

@@ -0,0 +1,8 @@
+#include <rp6502.h>
+
+int __fastcall__ f_seekdir (long offs, int dirdes)
+{
+    ria_set_ax (dirdes);
+    ria_push_long (offs);
+    return ria_call_int (RIA_OP_SEEKDIR);
+}