gEDA-user: round dots and square dots

[DJ Delorie]

>    1) Way do the network connections on the ground line show as squares?

Probably because your monitor has a limited number of pixels to use,
so sometimes the dots show up as squares, but it's only by accident.

>    2) Way can't I connect the bottom of the battery to the network?

We'd need to see the .sch (preferably, with the components embedded).

>    3) Can anyone explain how this type of circuit work?  I included the
>       URL for the information source.  I don't know how the LM7805 can
>       control the TIP2955s?

It looks like R4 turns the current drawn by the 7805 into a bias
voltage for the transistors.  Thus, by drawing more or less current,
it can bias the transistors more or less.  I.e. it's a current
amplifier.  However, R1-3 limit the transistor's contributions to only
a few tens of milliamps, far less than the 7805 can provide on its
own.

Ah, I see the problem.  Your circuit has 1000 ohm resistors, the original
circuit has 0.1 ohm resistors.