Linux "boxes" and EMC

OK... I'll unlurk... But I warn you... You opened the can
and let the worms out!!!

I sympathize with all the Lurkers out there shaking
their heads over the "Linux/rtlinux/emc" install woes.
I actually began Installing Linux and RTlinux about
six months prior to this list and before I was aware of
EMC. So I had six months to "figure it out" (ha ha
if you can EVER figure ALL of any operating system!!)
So with this "EXPERIENCE" I have a small "KERNEL" (ok
a bad computer pun) of advice!!!.

BTW: before I bore you to death with more linux stuff,
wonder if there is "interest" in developing a standard
linux/EMC hardware platform. With new cheap motherboards out
there, it could be possible to identify a "cheap" emc
system and preload a hard drive with all the files, just
ready to run!!! (SORT of how Bill Gates got everyone hooked
!!!) anyone interested!!! email me!!! I would glady stuff
the hard drive full with EMC!! This would require that the
computer have "standard" hardware in it.

Now for my Delurking Diatribe!!!!


1) Stay away from 486 machines. They have many hardware
quirks that demand detailed knowledge. Sure they are
cheap enough... $5 to $40. But the problems outweigh the
cost advantages (assuming you value your time at more than
$2 an hour). They are great for "Linux Student" machines
because they force you to learn all about the various issues
and they are usually "boat anchors" not used for anything
else, so It is easy to justify dedicating them to linux.
Xwindows as used by XEMC will "run" on the machine, but
not without at least 32MB of ram and most 486's have
problems with more that 16MB. It is possible, but expect
it to take you several weeks worth of evenings to get it
right. Use the linux news groups for help. I search on
dejanews for "linux 486". Beware, the kernel recompile that
is needed for RT-LINUX will take several HOURS on a 486. This
can be very frustrating to first time users...

2) Don't try to fit all your computer needs into one box.
Though it is "nice" to run windows, Dos, and Linux one
one machine, this adds more complexity. These OS'es were
not designed to run with one another. It is sort of like
getting a cat, hamster, and a goldfish to live together.
Can it be done? Yes!! Is it worth it? NO. You will get
much more utility with a FEW seperate computers networked
together. This also provides redundancy in case you do
something "Stupid" ( and you will ... trust me!!)

3) An EMC box should only run EMC!! I have
a favorite mode I follow now. I dedicate a computer
to a task. This is slightly more expensive, but wastes
less time. The total investment in computer hardware is still
less than most of the other hardware (steppers,servos,mills etc).

4) Find old pentium class machines at computer stores or
computer shows. They can be had for $100 or so. I would
say 90Mhz and up, but I have little experience here. I had
trouble finding one I liked, So I decided to go the next
route (5) below.

5) Upgrade an old machine.
I take old AT class 486's and upgrade them.
with modern motherboards. I buy "cheap" AMD K6-2 motherboards
and processors to run linux. I find these are easy to
build or buy at computer shows and via catalogs. A 300Mhz
AMD K6-2 cpu is $40 and a motherboard is $80. If you have
a 1-2gig hard drive and a floppy,CDrom and used ram you are
set. I find computer show sales people can also sell bare
bones systems that you can put your existing hardware into.
My target system for EMC is:

AMDK6-2 300Mhz ($40)
32MB ram (64MB if I feel rich) ($38)
Super Socket7 motherboard (Tyan 1590s or SISM598) ($70-$90)
Floppy ($6)
cdrom ( optional ... only used for install then removed) ($30)
1 to 2 gig hard drive ( <$70 used)
case from an old AT computer (486 etc) ($5)
10MB ethernet card ($12)
PCI video card ($30-40)

With computer hardware constantly changing, it is difficult
to recomend things , but most low end AMD or Celeron systems
will be excellent from a speed point of view. The Kernel
recompile will be on 20minutes or so!!!


6) BEWARE OF VIDEO CARDS. Use PCI only, not AGP. This
is getting more difficult as PCI cards are dissaperaing
from computer shows. I check with the vendor to see if he has
anyone running redhat 5.2 on the card. This is the number
one problem that I have now. Also many new motherboards
have "ONBOARD AGP" which is a fancy way to say that they
integrated the video chip with the motherboard controller
to make it cheaper. I have one of these Motherboards and
it works well. But it was more difficult to get Xwindows
up and running on. Say and extra week (of evenings) of work.
A good ATI,Diamond,Trident card should be supported. Don't
pay too much (over $40) for a "better" card. you don't need
it!!! and it may be less compatible.


7)WIPE the hard disk FIRST. and use only 2 partions:
Linux and a Linux swap. Do not try to install on a
partially filled hard disk. First, You may run out of space
on a 1G drive if you install everything. Second, the problems
with lilo etc are not worth fighting!!!

8)Use the SERVER install if you want all the networking
stuff. The workstation install does not put all of it
in.


dave