GC> affords the entire system, will I be required to write a 
GC> device driver to access the CPU ring that allows direct 
GC> port manipulation?  Additionally, can someone provide some 
GC> information, perhaps direct experience, on the matter?

if ur doing it for self, you might consider a driver- there is
plenty of information about on it. it's a type of penance, and
may have salable aspects- driver coders are always at a
premium. but ask yourself- how well will it port to Power PC?

in terms of time to toy, using an existing port and driver is
obviously the way to go. you then beat the thermometer h/w
into compatible rapid submission.

the low-effort ports would be serial, parallel, and game. not
sure which of these is best or what game port driver there is.
you don't want to spend effort on the h/w, either. suggest you
check into which port (serial or game) you can set up for
unusual serial input streams. then check with Dallas. they just
fielded a new "direct-to-digital" temperature measurement
chip in an 8-pin mini-DIP. DS1620K. likely under $10 in 100s

half-degree C resolution 0-70C calibrated; spec. -55C to +125
(mil-spec range). 2 user-defineable setpoints. output appears to
be bit-serial 9 bits. response time appears to be long- about
one second- the usual problem when the sensor is buried inside
a big blob of epoxy. probably fine for your purpose.
1-(214) 450-0448. remember, the output is not ASCII serial,
just BIT serial and may or may not have start bits, etc.
remember- this sucker takes a SECOND to track changes, so
there's no need for 115Kbaud! you can run at 10 bits/s and
use software polling- somehow, you gotta provide a clock &
convert pulse, too.

Dallas offers a "starter kit"; i'd bet it plugs into a serial port
on a PC. if so, your only problem is to port the DOS code to
OS/2. if not, i'd be more interested in the game port driver
for OS/2, especially if I could make one of the button inputs
an output (presuming the game port was based on an 8255).

___
 X KWQ/2 1.2e X 3 deg. K: Not with a bang, but a whimper.

--- Maximus/2 2.02