W. eWatson wrote:
I have the fourth edition of Meeus (1988?) and haven't used it for quite
awhile. I just discovered a similar book by Duffett-Smith that may
pre-date Meeus. What's the difference between the two?

Which books precisely are you referring to? Both Meeus and
Duffet-Smith did books targeted for hand calculators and
more general purpose methods that are suitable for computer
implementation.

Duffett-Smith:
- Practical Astronomy With Your Calculator
- Astronomy With Your Personal Computer

Meeus:
- Astronomical Formulae for Calculators
- Astronomical Algorithms

Duffet-Smith's computer book contains a lot of BASIC program
listings, which may or may not be of use to you. Meeus' book
has a disk available containing the data and programs, but the
methods in the book are presented in mathematical form that is
not just pidgin BASIC.