IMHO, the new books from Radio Shack called "Basic Electronics" and
"Basic Digital Electronics" are very good entry level books. They are
not too involved mathematically(I have a degree in electrical engineering
so I mean they don't rely on calculus, linear algebra, vectors, etc.), but
are well illustrated and easy to understand. They may be too elementary for
some but to me they have a lot of useful, broad information that will serve
as a good foundation for further study.

At 11:24 AM 12/23/96 -0800, you wrote:
>I hate to make my first post to this list a classic rookie question,
>but I really want to get working on my project over the Christmas
>break.
>
>I have eight banks of eight LEDs arranged in a common cathode array.
>My original plan was to use a 74HC138 as a bank select, and wire PORTB
>to the anodes through current-limiting resistors.
>
>The 74HC138 can only sink ~25mA, so I was planning on presenting only
>one bit at a time on PORTB.  I did some more calculations, and I find
>that this approach will be too slow.
>
>So, I want to be able to sink more current (20mA/LED * 8LED = 160mA).
>This is where I start to get out of my depth.  I'm thinking eight PNP
>transistors (2907?) with the bases attached to the 74HC138 outputs, the
>emitters attached to the banks' cathodes, and the collectors grounded.
>But I don't know if I need current limiters between the transistors and
>the 138.  I don't know if I've chosen the right transistor for the
>job.  I don't know if the information presented in, say, the Digi-Key
>catalog is enough for me to pick the right transistor, or if I need a
>data book.  I don't know which data book covers these parts.
>
>I'm not describing my problem in order to have someone present me with
>a solution, just to describe my level of expertise.  The sci.electronics
>FAQ recommends _The Art Of Electronics_ (2nd ed), by Horowitz and
>Hill.  Is this a good book for someone at my level?
>
>Thanks,
>Brian
>
>