Pat Madden asked about having Guide set up to track asteroids.
(And, by extension, other moving objects: comets, planets, the
moon, artificial satellites.) Strikes me as a good idea, but I have
no real idea how to do it. The straightforward thing to do would be
to send RA/dec commands from time to time, but it's hard to get
any sort of smooth motion in that manner.

Somewhat more critically, the LX-200 protocol only allows you
to specify RA to the nearest RA second (15 arcseconds).

I _have_ heard of software that does a decent job of tracking by
sending directional slew commands ("set the following guiding/slew
rate... move left... move up... stop..."), all timed so that the overall
motion will be passably close to that of the target object. Dunno how
well this works, and don't remember any details. Anybody know
what I'm talking about?

Robert Burns asked about mechanical error correction. You're right;
at present, it works only on Tangent-style encoder boxes. This _will_
be fixed; doing so involves a rather major overhaul to scope control
in general. (The current system for scope control in Guide is not
something I'd ever want to mention on my resume. But as I replace it,
I at least know from hard experience certain mistakes _not_ to make.)

-- Bill