EMC is installed, So now what?

This may sound ignorant, and for that I apologize. Here goes:

I got a new office computer recently, so my AMD K6/II 400Mhz office
computer became my garage/cnc computer. Onto that I installed Mach 1
and TurboCNC with a dual boot OS and both seem to be running quite
well (thanks Art!).

So I was left with my old P166 which I decided I would try to install
EMC onto. I downloaded the BDI image and fired up the installation,
and other than a screen resolution that needs to be increased (can't
see the whole window), it seems to be running.

However I have a few questions:
1.) I know very limited Unix and this is my first time ever on
Linux. I can't find the screen resolution adjustment anywhere nor
can I locate the EMC ini file to let me enter in the port outputs &
motor tuning info.

2.) Why use EMC over TurboCNC or Mach1? What does it do better, if
anything at all? Is its only advantage that its free open source?

3.) Last question: When I run TurboCNC on the P166, the 8254
latency is lower than my AMD K6 II 400. By all accounts the 400
should be much faster (284mb ram vs 96, etc. etc). Is the 8254
(which I assume is a clock of some kind) latency a function of
motherboard layout alone and nothing else? What would affect this?

As always, thanks!

-Chris