Jim Fleig - CNC Services wrote: >Hi Steve, > >Thank you for the reply and answers. > > Sure.
>Questions inserted into your reply below. > > Answers inserted near the questions :) >>You can't save a configuration to the CD, >> >> >I'm not arguing. This is a sincere question. If a CD is a R/W CD, would it >be possible to erase some of the applications that are not needed for EMC >like Games? Would it be possible to erase configuration files that are not >needed and write a configuration to a R/W CD? > > I think Gene had a good description of CDs vs. hard disks, so I'll leave it there. >>but if you have a USB memory >> >> >I do. > >>tick, you can make a copy of a config >> >> >Does EMC have to be installed to create a config or can this be done while >using the CD? > > No, the USB stick is being used like a floppy in this case. You boot from the liveCD, you do some stuff, and you then put some data files on the USB stick. >>(in your home directory, which will be in ramdisk), >> >> > >I don't understand the statement about home directory and ramdisk. > The "home directory" on a Unix (or Windows) system is where your personal files go. On Windows it's usually under "Documents and Settings", then the user name (usually Administrator due to installation issues :) ). On Ubuntu Linux it's /home/username. This is just a place where files should be created for you by default, so they don't interfere with other users. The liveCD is a multiuser system, even though there will usually only be one person logged in. As for ramdisk - remember the days when floppies were really slow, and some people wanted to use some memory (usually high memory, then later extended and expanded) to store files, so they wouldn't have to wait for often-used things to come from disk all the time? That's what I'm talking about here. Ubuntu basically makes a RAMdisk so that you can save some files using the liveCD. These will go away when you turn off the computer, since they're in memory. > This is >what I think I know: computer turns on, bios in a prom on the motherboard >has a limited set of instructions that the computer follows to locate the OS >that will run the computer, OS is found and takes over computer operation >(example: XP). When the OS is up and running, then other programs can be >selected which have commands of their own to use computer resources while >the OS oversees all of the currently running programs. When a computer >boots and the bios sees that there is a source of OS in the CD drive or on a >USB channel, it allows that OS to run. > So far so good. >Here is where it gets fuzzy for me. >While running the Ubuntu CD it was possible to open the Word Processor >application. If a document was created while that application was open >would it be possible to save the document? > Yes. > If yes, where? > If you save it to your home directory (should be the default directory in the file save dialog), then it will end up in a ramdisk. I don't know exactly how the ramdisk is set up, so I don't know where else you can save files. > If the CD being >used were a R/W CD then it would make sense to me (although it might not >actually work) that the created document could be saved on the CD. It >doesn't make sense to me (keep in mind that I don't know what I'm talking >about, I'm just sharing my impression) that created data could be saved >using the hard drive, a USB memory stick, a floppy drive (yes, I have one >plugged into a USB port for old stuff I have to reference occassionally) or >a second R/W CD drive. This doesn't make sense to me because I don't >understand how the OS running on the CD would have the drivers to manage the >USB ports, other CD drives, etc. > > It's a liveCD. Linux is a little different from Windows in that it actually includes drivers for nearly everything by default. When the CD boots, it has full networking, USB, mouse, audio, most video, and other device drivers already present. Only "proprietary" drivers won't be immediately usable when booted from the CD (these are usually for high end video cards and the like). >>then copy that to the USB stick. Later, when you >>go to do the demo, you can boot from liveCD, and copy the config back to >>your ramdisk home directory and select it from the config picker. >> >> >Once I understand the directions above this will probably be as simple for >me as the file copy and paste that I do so often now. At the moment, I >don't understand the statement above. What is the ramdisk home directory? > > If you go to the "Places" menu, the first item is "Home Folder". This is your home folder (for whomever is logged in at the time). When you plug in a USB stick, a window is likely to open automatically (if not, it will be under the Places menu also, probably labeled "USB Disk" or similar). You can drag and drop between them. One thing to note: middle-drag on Linux is the equivalent of right-drag on Windows, the one that lets you select copy/move/link/cancel. >>There are other ways to do this which are more transparent (things >>written to the file system automatically end up on the USB stick), but >>that's a bit harder to set up and is probably not needed for this purpose. >> >>- Steve >> >> >Thank you for all of the explanation above. Ideally (I don't know if this >is possible) it would be possible to send someone a CD, they would boot from >the CD, EMC would auto load, they would be able to follow hardcopy >instructions that came with the CD and perform manual and MDI functions and >load a program and run it with EMC. Am I dreaming? If no, what is needed >to make this happen? > > Weeeelll. You can do this, but it's not trivial. I don't know how to do some of it, but I'm sure it's possible. First, putting your config on the liveCD: Under Linux, you can mount the ISO image which is on your hard disk, and you can copy the new config there. This is done using the loopback device: mount -o loop -t iso9660 /path/to/livecd.iso /mount/path I'm not sure what happens to bootable CDs when you do that though, I've never tried it on a liveCD. Putting your config under the /etc/emc2/sample-configs/ directory (on the CD) will make it appear in the config picker. You would of course need to burn the modified ISO image to a CD. The livdCD already does auto-login, so getting EMC2 to run should be as simple as adding a line or two to a config file. I don't know which one though :) As I said, I'm not sure what happens to a bootable ISO image when you modify it using the loopback method. The more complex route is to do the whole process of creating a liveCD, but that's a royal pain to get going. You can also make a bootable USB stick, if the machines you want to demo on are capable of booting from USB. There are instructions around for installing to a USB stick, which makes your home directory persistent across reboots (and across machines). Sam Sokolik used these at one point <http://www.ryancloke.com/ubuntu-804-hardy-heron-live-usb-how-to/>, suitably modified to use the EMC2 liveCD. Les Newell recently documented installation to a flash drive, which should be similar for USB (maybe - I haven't read that one) <http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Install_To_CompactFlash>. >Thanks again for all of the answers. This is an area where I obviously am >uneducated but willing to learn. :-) > > Aren't we all? Err - well, you know :) - Steve ------------------------------------------------------------------------------ Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM) software. With Adobe AIR, Ajax developers can use existing skills and code to build responsive, highly engaging applications that combine the power of local resources and data with the reach of the web. Download the Adobe AIR SDK and Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
