I have a number of older rackmounted computers that I would like to use
for CNC usage.
What are the requirements (CPU, MHz, HD size, video) that is needed for
the popular types of software in use today?
Does anyone use rack mounted computers? If so, how do you have them set
up in your shop environment?
Since I have a number of them, where should one draw the line as to
what to keep and what to toss?
Is there anything one should salvage from the old computers before one
Why don't you go to your chosen CNC web site and see what
their software requires for CPU hardware. I think in this
case you may want to find the software first, then see what
will work on your hardware. Remember though, that you already
have "old" computer equipment, and that it will become
obsolete even faster than current equipment, meaning the next
update of your favourite CNC software may exceed the computers
ability to function.
And very important, DO NOT use the computer in a non-clean
(dust free) enviroment, like your shop. The airflow through
the computer needs to be dust free.
Computers are a lot tougher than folks are led to believe. I doubt the
"dust" problem is any worse in your shop than it is under the average
computer user's desk.
I have 2 in cars (desktops, used as MP3 players) that start up in the
Florida heat and run fine. The MP3 PC in my garage/shop survived a
fire and it is still going fine.
If dust really bothers you, put some of that "cut and install" filter
material over the air intakes.
That and depending on what you do in your shop (grinding, plasma
cutting, machining graphite, etc.) you can have conductive dust that
will short things out very quickly.
I worked on some CNC machines in a shop that machined graphite composite
molds and *everything* in their shop was sealed. Everything normally
open drip proof was sealed up, the control cabinets had A/C ducted in
and out and the cabinet doors were sealed with duct tape, etc. All the
even with a truly massive dust collection system that once sucked up a
1" micrometer that was placed near one of the collection hoses and
lifted it 20' to the ceiling and then 100'+ to the dust separator and
deposited it in the collection drums.
You might look at the later IBM 75xx series, the 7585 and up. They have
the ability to mount filters in them. They MIGHT get up into the P3
range, but I'm not sure.
[BTW, I'm looking for any IBM 7568 "Gearbox 800" industrial computers or
I've seen computers caked with dust and still working, but with the
advent of GHz CPUs, having a dust buildup on the CPU heatsink is dicing
Pete C. wrote:
Those were PS/2 boxes and I doubt if any of them could even be hot
rodded up to a PII. Go over to comp.sys.ibm.ps2.hardware and ask
around. Those guys are still holding the flag on these machines and
they know more than IBM does these days.
In real life you could make a box to put your PC in with big filters
and a big fan if you think it is a problem. We are supposed to be
My garage PC/MP3 player is in a wood case but so are most of my
Greg, the 7568 was the only IBM industrial computer that used a passive
backplane AND MCA interposers. The 758x and higher had PII, I'm not sure
which because they are PCI or PCI/ISA.
It uses a Socket 3 and tops out with a DX4-100 or a Turbochip. Limited
to a maximum of 32MB of FPM [a fifth bank of 8MB provides ECC). I'm
afraid the current CNC programs would find it excruciatingly slow if not
generate a hang trying to step the servos fast enough.
Did it pass calibration afterwards?
"I think this is because of your belief in biological Marxism.
As a genetic communist you feel that noticing behavioural
patterns relating to race would cause a conflict with your belief
in biological Marxism." Big Pete, famous Usenet Racist
I normally would go to the various CNC sites but if you do you will
find that they are deliberately vague about what computing power they
In addition, I have the old computers NOW and many of them are rack
mount systems that are very expensive to replace. Considering that they
are setup for running in less than desirable environments, it would be
a shame to toss them if they could be used in homebrew CNC setups.
One thought I have is if the CPUs are not powerful enough, one could
retrofit the cases with newer electronics....but first one needs to
assess if the older electronics are insufficient for the CNC software
that is popular today.
So has anyone done this analysis...with all the older computers out
there I would expect this to be of interest to many people.
Perhaps I should also ask what type of CPU power do you have in your
shop? While my immedicate interest is in CNC, a computer has many uses
in a shop environment.
=========================You may just need to replace the motherboard, CPU and memory in
the existing rack mount enclosure. I would suggest getting the
exact model numbers of what you have and contacting a vendor that
specalizes in hardware upgrades. If you have a digital camera
photos may also help.
I have had good luck with Tiger Direct.
for example you can get an Intel D865GVHZL & Celeron D 340
2.93GHz processor for only only $79.99 after rebate and add 1 gig
of memory (2) each Ultra 512MB PC3200 @ $39.99 after rebate or
160$ total for an upgrade. You may want to upgrade your hard
drive and add a cd/dvd burner.
Generally a "do it yourself" job if you take it slow and don't
What operating system(s) are you using?
There is something to be said for government by a great aristocracy
which has furnished leaders to the nation in peace and war for generations;
even a democrat like myself must admit this.
But there is absolutely nothing to be said for government by a plutocracy,
for government by men very powerful in certain lines and gifted with the "money
but with ideals which in their essence are merely those of so many glorified
Theodore Roosevelt (1858-1919), U.S. Republican (later Progressive) politician,
president. Letter, 15 Nov. 1913.
"What operating system(s) are you using? "
I think you are on to something here George.
At first glance the biggest tipping point seems to be whether or not
one uses a WIndow interface.
Without Windows means you can live with a much slower
machine....controlling steppers or servos really doesn't take much from
I suspect that this dividing line is what I am trying to determine
through my questions as to "how fast".
Maybe the real queston is "How much of a machine do you need to run the
Windows environment you are forced to run?" Anyone know the answer to
that.....what are the real MINIMUM requirements for a machine when you
need to run Windows (3.1, 95, 98, Me, XP)?
Along with "how fast" also comes the questions of how much RAM and hard
As to what operating systems I will be running? Well it will likely be
whatever these machines will handle.
F. George McDuffee wrote:
Windoze, all versions above 3 require "protected mode" and that
happened at the 286 level. I saw W/95 running on a 386SX with 6 meg of
storage but it was crawling in the mud. Click the mouse, go get a cup
of coffee. It might be done when you get back.
When I looked it seems the version 1.x software is W/3.1 and up so
damn near anything should run it. The version 2.x is NT or XP only so
that pretty much gets you up into the PIII neighborhood, just to
support the bloated operating system.
I can't see why a 4.88 mz XT wouldn't be enough to run the machines
but the cartoon interface may be a power hog.
One of the first CNC's I ran was a conversion of a hardinge chucker. It used
an old XT for a controller. Also used an EGA monitor with dual 5" drives. I
don't think it even had a hard drive. Operating system was in one drive and
programs in the other. It even cut threads.
They have an old green screen Okuma LC40 and it takes forever to boot up.
I think it's over 25 years old, so it can't be running very fast.
"I can't see why a 4.88 mz XT wouldn't be enough to run the machines
but the cartoon interface may be a power hog. "
The "cartoon interface" IS the power hog...note how little CPU power
text based CNC applications use.
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