gEDA-user: furnace controller I/O port again

[DJ Delorie]

> Which frequently gets people into trouble when they try to use
> Op-Amps as Comparators:

There do seem to be comparators in the size, speed, and type I need;
although not as plentiful as op amps.

Specs:

* push-pull output (they drive both P and N MOSFETS).

* 1MHz or so (~1uS delay)

* <= 0.65mm pitch (ideally, 0.5mm)

* 3.3-5v Vcc

The lines will (initially, at least) carry 1wire (1-15 uS pulses) and
RS-232 (9600 baud).