flushing STDOUT before reading STDIN

[Clinton A. Pierce]

A small annoyance, I can't seem to write a good line-input routine as of 
very recent changes (synced yesterday, noon).  All I'm trying to do is 
variations on:

        print "? "
        readline S0, 0
And no prompt shows before the readline starts its business.  Any 
suggestions as to how I can flush stdout before beginning input and 
whatnot?  I'm not above resorting to PASM hackery at this point, since the 
I/O is in flux.