dvilj Font Basics?

I started muddling through _The METAFONTbook_.  Recently, I got to
Chapter 5, in which Knuth prompts his readers to give METAFONT a spin.
Everything went well (enough) until I was faced using TeX.

Knuth says you might have to find a local wizard to figure this out,
but usually I am that wizard.  I put my io.tfm file in
/var/cache/fonts/tfm/local/io/io.tfm, and I put io.2600pk in
/var/cache/fonts/pk/ljfour/local/io/io.2600pk, and then I ran texhash.
TeX seemed to find the io.tfm file, and dvips seems to find the
io.2600pk file, as does kpsewhich.

But dvilj4 doesn't seem to find the io.2600pk file, and I don't know
how to make it wise.  Or, more likely, it's not even looking for my
io.2600pk file.  dvilj suggests that I forgot to run dvicopy, but
running dvicopy blindly (without knowing why) to make a second dvi
doesn't make any difference: when I print the resulting .lj file with
my LaserJet 1100, I get a nearly-blank page, with all the text typeset
in Computer Modern showing up fine, and all the text typeset with my
`io' font simply being plain, blank, white space, with no glyphs
printed at all.

So I've simply switched to using dvips + ghostscript, which is easy
enough, albeit slow.  Still, I would like to know how dvilj looks for
its bitmap fonts.

What do I need to know about dvilj, and how shall I learn it?