Peter's Linux Q&A

  1. How can users other than root mount the floppy and cdrom?
  2. How do I format a floppy disk?
  3. How can I increase the mouse speed?
  4. How much memory does my machine see?
    What are the assigned IRQ's on my machine?
    Which PCI cards does my machine see?
    What are the assigned I/O addresses?
  5. Linux only sees 32MB of RAM. I thought I had more than that!
  6. How can I set up my Voodoo card?
  7. What about Sparq drives?
  8. How can I fine tune my hard drive?
  9. How do I get my TV/radio card working under Linux?
  10. I have some wierd nameless board that I have no specs for. What do I do?
  11. Is my modem compatible with Linux? How do I know if it's a winmodem? What about faxmodems?
  12. OK, I have a winmodem. Now what do I do?
  13. How do I get my modem to dial silently?
  14. What video card should I get?
  15. What network card should I get?
  16. How do I share my printer with people on a LAN/Internet?
  17. How do I access an Iomega ZIP250 parallel port drive?
  1. How can users other than root mount the floppy and cdrom?
    You can add a `user' flag to the /etc/fstab entry for your floppy or cdrom drive:

    /dev/fd0/mnt/floppyext2 noauto,user00
    /dev/cdrom/mnt/cdromiso9660 noauto,ro,user00

    But in the name of security, the user option implies noexec, nosuid and nodev, so you must explicitly put exec, suid or dev in the fstab entry if you want these features.


  2. How do I format a floppy disk?
    First you must format the disk. If you have a normal floppy drive 1.44MB standard IDE device (if you don't know, this is probably what you have).
    fdformat /dev/fd0H1440
    Next you need to create a file system on the floppy.
    mkfs -V -t ext2 /dev/fd0
    This puts ext2 on the floppy (you could also put msdos if it's configured in your kernel) with verbose output.


  3. How can I increase the mouse speed?
    Look up xset in the man pages. Give this a try:
     xset m 5/1


  4. How much memory does my machine see? What are the assigned IRQ's on my machine? Which PCI cards does my machine see? What are the assigned I/O addresses?
    Memory:cat /proc/meminfo
    IRQ Assignments:cat /proc/interrupts
    PCI Assignments:cat /proc/pci
    I/O Addresses:cat /proc/ioports


  5. Linux only sees 32MB of RAM. I thought I had 128MB RAM!
    In /etc/lilo.conf add the line
    append="mem=128M"
    This is given as an argument to the kernel, telling it that you have a full 128 MB of RAM (of course, substitute 128 with how ever much you have). You'll have to run /sbin/lilo after you make the change to your /etc/lilo.conf file. Then you need to reboot.


  6. How can I set up my Voodoo card?
    First of all, the canonical linux 3D sites are:
    1. http://www.linux3d.org which is owned by Mr. Linux3D himself, Daryll Strauss (Rhonda Bailey, Bill Kendrick and Mike Simons and I went to go see him talk at SVLUG :) ).
    2. http://glide.xxedgexx.com is a mirror of the above site (vice versa?).
    The above sites are for *all* 3D cards under Linux. They also contain things like linux 3D news (which companies have recently decided to release their specs, the status of the mesa project, etc), hardware, software and much more.

    If you have the SUSE distribution (my personal favorite), there is an excellent article by Rene Reucher which deals with the Voodoo3 and Voodoo Banshee cards under Suse linux. You can download the postscript version or the pdf version here. Alternatively, you can go to the original source which might have a later version (the versions here are version 1.1 dated 8July99).

    There is another very good site which is distro independent, titled 3Dfx Voodoo3/Banshee Linux How-To.

    There is also a Voodoo3/Banshee guide for newbies.

    If you use Debian, there is a guide specifically for your distribution at http://crash.ihug.co.nz/~trmusson/home/3dfx/debianv3.html

    There is a guide with hints and tips on how to set up Quake II and Quake III for a Voodoo3 and Voodoo Banshee card at http://web.missouri.edu/~ccblake.


  7. What about Sparq drives?
    Linux supports them. If you need to buy cheap cartridges or get them repaired, go to this site which is owned by a company named IMI. For a site devoted to the Sparqs, there is the Unofficial SyQuest Site.


  8. How do I fine tune my hard drive?
    The command hdparm provides a command line interface to various hard disk ioctls supported by the stock Linux IDE/ST-506 device driver. Fine tuning represents changing the way the system uses DMA (Direct Memory Access) and hardware interrupts.

    By default, Linux uses very conservative settings for IDE (Integrated Drive Electronics) which are sure to slow your hard drive down. First, it doesn't use DMA, which means that data going to and from all IDE devices is processed by the CPU, byte by byte. By using DMA, the data goes into main memory without ever seeing the CPU.

    The 2nd problem is that hardware interrupts are masked during IDE transfers, meaning that while data is getting bunched together for transfer to and from an IDE device, no other interrupts are processed. Basically, the machine is just waiting around until the IDE devices are done with their tasks. This slows performance with any other devices connected to the machine, such as modems, network devices and serial devices. This could freeze your PPP connection or make your mouse inactive.

    Linux defaults to this lame behavior because there's some hardware out there, like CMD-640B and RZ1000, with bugs which cause errors in IDE data transfers or can cause massive filesystem corruption.

    To enable DMA and interrupts during IDE transfers, use:

    hdparm -u 1 -d 1 /dev/hda
    if your hard drive is hda. This change will get wiped out during a reboot, so you'll prolly want to put this in a startup script so it gets run if you ever have to restart the computer.
  9. How do I get my TV/radio card working under Linux?
    The kernel driver is called bttv and can be found under the video4linux section of the kernel configuration. An excellent resource for TV and radio cards is http://www.exploits.org/v4l/ . This page has a list of all the supported hardware and their drivers. It also has all the TV/radio applications that I've ever seen (13 last I checked) but the one that most people seem to use the most is xawtv.


  10. I have some wierd nameless board that I have no specs for. What do I do?
    The thing will have an FCC ID on it. You can plug this number into the web interface at http://www.fcc.gov/oet/fccid/. (Thanks Foo Lim).


  11. Is my modem compatible with Linux? How do I know if my modem is a winmodem? What about faxmodems?
    This isn't the end of the story. Some modems have flash upgradable firmware which only works under Windows. These modems will operate fine under Linux, but you won't be able to upgrade their firmware. Furthermore, if you're out to buy a faxmodem, aim for a modem which supports Class 2 or Class 2.0 faxing. Steer clear of Class 1.

    See The Hardware HOWTO for more details.

    If you're unsure about whether your modem is a winmodem or not, there's a monster site which keeps track of all modems and their compatibility with Linux. Everything you ever wanted to know about modems is either there or has a link at this site.


  12. OK, I have a winmodem. Now what do I do?
    If it's at all possible to get your winmodem to work under Linux, go to the Linmodem website.


  13. How do I get my modem to dial silently?
    Most likely, all you need to do is initialize your modem with ATM0 instead of ATZ.


  14. What video card should I get?
    There's a couple considerations here. For instance: to be continued


  15. What network card should I get?
    Donald Becker, author of just about all the ethernet card drivers for Linux, emailed me a detailed account of why some network cards are better than others. You can read it by clicking here.


  16. How do I share my printer with people on a Internet?
    If you want to share a printer with a friend on the internet, then add the following line to /etc/inetd.conf:
    <port> stream tcp nowait root /usr/sbin/tcpd lpr
    Leaving an open network service like this is considered extremely insecure, so you'll want to use ipchains to limit service to only your friend's IP address.
    ipchains -A input -s a_friends_ip -d your_ip lpr_port -p tcp -j ACCEPT ipchains -A input -d your_ip lpr_port -p tcp -j DENY
    There are more to the options than what I show below, but I intend to give you an overview of what the above lines mean, rather than all the possibilities.
    -A input appends this rule at the end of the input chain.
    -s is a source address: an IP, hostname or network.
    -d is the destination address followed by the destination port.
    -p is the protocol this rule will apply to (this will be tcp).
    -j what to do when the rule matches. j stands for `jump'.
    So when your friend's ip attaches to your ip's lpr port with tcp, the rule is "jump" to accept the packets. Otherwise, the rule is to "jump" to deny the packets.

    These chains will vanish after a reboot, so put them in a script that will be run at boot, ideally before inetd is run.


  17. How do I access an Iomega ZIP250 parallel port drive?
    First of all, did you know there's a HOWTO for zip drives?

    The short answer is that this drive uses the imm module. So as root on the console, type modprobe -a imm. This will load the module. Next, you need a mount directory. If you don't already have one, make a mount point (I like /zip).

    Next, mount the drive with mount /dev/sd[x]4 -t vfat /zip. Here, [x] is the next available SCSI drive letter. For example, if you have a single SCSI device not including the zip, [x] would be b. If you have 2 devices, [x] would be c. The 4 means partition 4. Preformated zip disks are always vfat formatted on partition 4. I think this has something to do with where Macs look for data on a disk.

Please report bugs or broken links to me. vim:tw=113