Actually, it wasn't the "AUTOLF" that was needed, it was "auto CR on
LF", but that's the root of the problem.  Sigh.  That's the *second*
useless default the DECcolorwriter has (the first being A4 size paper).

A number of people suggested using the non-interrupting device
interface; this turned out to be unnecessary (though I might anyway,
since it actually looks like it would be less of a load on the system,
somewhat to my surprise).

Thanks again, and my apologies for the wasted bandwidth.

Oh, the "gibberish" I talked the driver into printing?  I added the line
	printf("%c", *sc->sc_cp++);
when I really wanted
	printf("%c", *sc->sc_cp);
Grr.