[IMSlo]

I just bought a new laptop. It is equiped with a 160 GB harddrive and of course Vista. I am toying around with installing Ubuntu and EMC2 as a dual boot system because I think the harddrive is big enough to handle it. I built JRGO's machine a couple years ago. I have always wanted some type of graphical display but can not justify buying software because there is no return and I only run the machine occasionally.

I have two gnawing questions that I must resolve before taking the plunge.

I am running a Hobby CNC 4aup (or what ever number) chopper board and of course it is connected to the computer via parallel port. My new laptop has nothing but usb ports. I saw a usb to parallel port cable where I purchase my computer. It was very overpriced ($50). I was just trying to find out if there was such a thing. I could probably get one much cheaper with a little research.

Now after all that blabber question #1.
Will this usb to parallel port work with EMC and my chopper board?

Question #2
All of my G Gode will be generated by Windows applications.
Will Windows generated G Code work with EMC2?

Thank You.

[samco]

First I would download the live cd from http://www.linuxcnc.org/content/view/21/4/lang,en/
and run the latency test on it.
http://wiki.linuxcnc.org/cgi-bin/emc...I_Latency_test
to even see if your portable will work.. Newer portables, well portables in general, have issues with realtime.

A usb to parrallel conveter will not work..
You might be able to get a pcmcia card (pccard) to parallel converter although I don't know 100% if that would work.

Yes - gcode made in windows will work in linux. (you may have to edit the post to work with the emc2's ngc format. It is similar to fanuc)

[pminmo]

Right now your options is usb and proprietary software, or a parallel port card and windows software like Mach3 or Linux and EMC2 with the parallel port card.

[IMSlo]

Thanks Samco

I guess your reply pretty well killed this idea.

I won't go to a lot of trouble to do this and I'm certainly not going to screw up my shiny new computer trying to do it.

[neilw20]

Welcome to the wonderful world of no backward compatibility!!, driven by the BIG HUNGRY manufacturers. I use win98 and XP junkbox computers. Join em all together with network cables, so you can use the best platform for whatever software/hardware (that still plugs in).
Interrupt latency is a real issue with real time control. More horsepower (=$) usually wins, but do we hit a golf ball with a cricket bat?

[Meduza]

http://www.superlogics.com/parallel/...-961.htm#fdesc

I belive this one would work, tough i have not tried it.

[NC Cams]

There are a couple more potential issues that one can face with a laptop and LPT port.

The laptops tend to use low power 3.3 or so volt LPT's. These can cause problems if the BOB that you're using are looking for higher power, 5volt digital "HIGH's".

The next issue involves real time interfacing to/with the LPT port. The power conservation programs used in some laptops can result in power being interrupted to the LPT port when the uP thinks it is ok to do so.

In any number of prior instances (do a "laptop" search on the site) these and other reasons why laptops should NOT be used for machine control have been cited. You are more than welcome to ignore this suggestion and/or recommendation, at your own peril of course.

[IMSlo]

I appreciate all the replys.

I am now running an old HP 166mhz with 32k ram and Windows 98 that I actually dug out of a dumpster. It has proven to be the most dependable machine that I have.

I guess the laptop thing is over with.

[ger21]

You can run Mach3 under Vista with an ncPod through USB. http://ncpod.oemtech.com/

[cnczoner]

Most (but not all-) USB-to-parallel converters are designed for just printers, so do not connect all the signals. You need a "True EPP" or "True Parallel" converter. Google should find it for you. Verify that it produces proper 5V signals.

On the SW side, FTDI makes a chip that allows electronics tinkerers to use USB ports. Not suggesting that you fiddle with electronics, but they apparently provide a driver that acts as a parallel port on the PC side (so the application "talks parallel") then converts it to USB signals out the USB port, and their specialized chip converts the USB signals to parallel signals (for interfacing to a microcontroller, etc). I know they make a USB-to-serial converter, but perhaps a USB-to-parallel also, and I'd think this would solve your problem. You can contact/ask them here... http://www.ftdichip.com/Products/FT245R.htm

Cheers,
-Neil.

[cnczoner]

BTW, this statement is interesting as it suggests that Ubuntu requires tremendous harddrive space, which is contradictory to my Linux experience. I've always felt that Linux needs much less resources that Windows, though I'm not sure of what's in the Ubuntu distrib. I actually have a bootable linux distrib running on a 64mb flashdrive! :banana:

Or were you suggesting that you had enough space for a dual-boot system? If so, I should point out that I'm currently running Suse and Win2k on a 30GB HD currently with lots of space leftover for my data/photos/etc.

Cheers,
-Neil.

I just bought a new laptop. It is equiped with a 160 GB harddrive and of course Vista. I am toying around with installing Ubuntu and EMC2 as a dual boot system because I think the harddrive is big enough to handle it. ...

[samco]

The issue isn't as much usb-> parallel... It is that Emc2 dosn't have a realtime usb driver. Usb doesn't lend itself very well to realtime so none of the developers have wrote one. The ncpod is a motion controller.. The motion gets downloaded to it from mach - and it runs from the ncpod. This would not be a good match for emc also.

Equipment that moves the motion outside of emc isn't a good match. EMC is a closed-loop motion controller, unlike anything else that's affordable by hobbyists. Steppers work because EMC fakes itself out with a made-up position value for the loop control.


The

[NC Cams]

In an oversimplification:

THe early LPT ports for the 8088 thru 486 PC's were essentially real time DOS connected to the UP. As the movement to Windows gained momentum, the care and planning that went into real time monitoring of the LPT port by the processor became burdensome, especially when the "LPT port only is there to dump a page to the printer". This is a far different requirement than what's needed for real time machine control.

Suffice it to say that unless the machine operating code takes control of the LPT port, the uP may still think it is merly dumping a page to a printer. This page dumping can be done willy nill and with littly regard to real time control - not the case when you can NOT have a servo being run by the LPT port stopping or dwelling while the uP does whatever it wants to do with whatever other multitasking effort that is knowingly or unknowingly going on.

I"m not an expert by anymeans with LPT ports. However, I've learned via studious reading of the "Zone that the newer PC's and especially laptops are not necessarily LPT/machine control friendly due to real time issues.

There are probably ways around that problem - yet, amazingly enough, guys get the stuff to work and also never get around the problem - it all depends on the PC and/or the DNA of the O/S in concert with the hard wired logic on the M/B.

I agree that there is immense charm in the use of inexpensive PC's when it comes to inexpensive DIY machine control. Sadly, however, few if any PC's are/were ever designed with machine control in mind. For that reason, they don't always adapt well to doing same, especially not anymore with the once readily adaptable LPT port.

It is too bad that some enterprising machine control guru doesn't craft up a PC104 or some other backplane device that is specifically suited to machine control for the DIY.

We have servo drives and software but we're still dealing catch as catch can hardware. SUrely, there is a way to "standardize" on an O/S (98SE, XP, whatever) and a decent affordable m/b that will simplify the DIY process. Rest assured that whatever the Wintel wizards do, it won't last and it won't be bug free.

Now I see why Fanu, Mazak, Haas et al create their own software and O/S. Why should they reinvent the wheel when Gates and Co decide they want/need another billion in profit and more control over what I do on my PERSONAL computer. Big brother is here and he lives and thrives quite well at M/S corporate headquarters.

Caveat emptor and forewarned is forearmed.

[samco]

The main downfall with latptops and sometimes with pc's is its power saving and processor scaling or anything 'outside' the control of the os. Another big issue is computers that have shared memory video cards. The linux realtime kernel has a cool test program that lets you know what your latency is and if your getting overruns.

http://wiki.linuxcnc.org/cgi-bin/emc...I_Latency_test

I have installed emc on a lot of hardware. Some have had better real time latency than others. I have had to disable onboard video and install inexpensive pci/agp video cards. I can't remember if I have come across a computer that I could not at all get to work. Some have I know. I was lucky with my portable - I was getting overruns - but it was a intel smi issue that there is a patch for.

sam

In an oversimplification:

THe early LPT ports for the 8088 thru 486 PC's were essentially real time DOS connected to the UP. As the movement to Windows gained momentum, the care and planning that went into real time monitoring of the LPT port by the processor became burdensome, especially when the "LPT port only is there to dump a page to the printer". This is a far different requirement than what's needed for real time machine control.

Suffice it to say that unless the machine operating code takes control of the LPT port, the uP may still think it is merly dumping a page to a printer. This page dumping can be done willy nill and with littly regard to real time control - not the case when you can NOT have a servo being run by the LPT port stopping or dwelling while the uP does whatever it wants to do with whatever other multitasking effort that is knowingly or unknowingly going on.

I"m not an expert by anymeans with LPT ports. However, I've learned via studious reading of the "Zone that the newer PC's and especially laptops are not necessarily LPT/machine control friendly due to real time issues.

There are probably ways around that problem - yet, amazingly enough, guys get the stuff to work and also never get around the problem - it all depends on the PC and/or the DNA of the O/S in concert with the hard wired logic on the M/B.

I agree that there is immense charm in the use of inexpensive PC's when it comes to inexpensive DIY machine control. Sadly, however, few if any PC's are/were ever designed with machine control in mind. For that reason, they don't always adapt well to doing same, especially not anymore with the once readily adaptable LPT port.

It is too bad that some enterprising machine control guru doesn't craft up a PC104 or some other backplane device that is specifically suited to machine control for the DIY.

We have servo drives and software but we're still dealing catch as catch can hardware. SUrely, there is a way to "standardize" on an O/S (98SE, XP, whatever) and a decent affordable m/b that will simplify the DIY process. Rest assured that whatever the Wintel wizards do, it won't last and it won't be bug free.

Now I see why Fanu, Mazak, Haas et al create their own software and O/S. Why should they reinvent the wheel when Gates and Co decide they want/need another billion in profit and more control over what I do on my PERSONAL computer. Big brother is here and he lives and thrives quite well at M/S corporate headquarters.

Caveat emptor and forewarned is forearmed.

[cnczoner]

The main downfall with latptops and sometimes with pc's is its power saving and processor scaling or anything 'outside' the control of the os. Another big issue is computers that have shared memory video cards. ...

Yep. Any decent laptop should allow you to disable most of the unwanted power-saving features, with the AC power supply connected. But the OS also has it's share of power-saving "features", which should mostly be disable-able.

I'm here in the EMC forum as I'm looking at it as a more stable option than Winxx/Mach 3, which requires "tricks" to get it to handle real-time processing. As with everything I do, I'll take stability/reliability over features, speed and even over convenience.

My current thought is to run EMC on a mini-ITX or mATX mobo which would be built right into the CNC controller enclosure (with appropriate cooling fans of course). The enclosure is pretty unique/large so it will fit.

Cheers,
-Neil.

[samco]

What do you feel is missing feature wise? I don't think 'speed' is an issue as emc should be able to output atleast the pulse rate that mach does and maybe even more.

I can see the convenience as far as learing a new operating system.. I came from windows only and only looked at linux over the last few years. I am very comfortable with it now. My portable is dual boot - I find myself using xp and ubuntu evenly. 50/50. If I have issues I can always ask on the forums or irc.

I'll take stability/reliability over features, speed and even over convenience.
-Neil.

[cnczoner]

Oops, didn't mean to suggest that anything specific is missing from EMC, especially because I've only run the live CD to get a feel for it and not actually machined anything yet (until I get the PC fully setup). I've read however that Mach3 has more features, but I can't say that myself yet.

And exactly as you say, I expect EMC would outrun Mach3 and be more stable, due to past experience with Win-vs.-Lin apps like this. I already found a few bugs with Mach 3, which has me worried.

[samco]

I was literally just wondering.. I have not used mach and the emc developers like ideas for features/impovements.

sam

[NC Cams]

I have a dumb question: What's wrong with DOS???

It is essentially free, it is as stable a platform as anything I have (95, 98SE, ME, haven't done XP cuz I don't want to buy all new PC's.) as long as I don't get fancy with multitasking.

One would think (again, i'm no expert) that machine code could be written to run on DOS that would run real time and not have to deal with latency and other "windows" baggage - espcially with the rocket ship backplanes that can be sourced for dedicated machine control - I fear that PC's are being developed so ad NOT to facilitate doing what M/S and the 'gamers' and office folks want as opposed to what CNC machinists want/need..

Some of us are only looking to have the machine run. We do not need to surf the net, run e-mail and do whatever else while the machine runs. Enought guys get 98SE to run with DOS programs in DOS window reliably that you could still use what should be a reliable 98SE or the like system.

I recall someone with a comp sci background "hacking" into his Haas and finding that it was essentially running a variant of DOS 7. If it is good enough fo multi-axis Haas (and the now defunct mid/late 90's Bridgeport VMC's, V2XT's, EzWhatevers and Explorers with BMDC's), why wouldn't it still be viable now???

Drivers and graphics issues asside, aren't we getting too caught up supporting M/S's business model. Wouldn't it be nice if some enterprising soul crafting up a better computer model better suited to REAL TIME MACHINE CONTROL that was affordable and did not have to be figured out/adapted/trouble shot each and every time?????

Sorry for the rant.

[pminmo]

Biggest problem with dos is graphics standard and memory model and lack of new hardware support. Try running a wifi card on dos for example. This is where linux is coming in as a viable alternative. You can run small distributions of linux such as dsl or puppy on machines that are both old and new. I mean 386 era machines up. I'm pretty impressed with puppy linux. Linux big downfall is installation of applications, and emc2 is not just install and go. I wish I were linux savy enough to build a a current version puppy distro with emc2. There is an older version of puppy with emc2 out there floating around, but.....