[K12OSN] Pentium 166 mHz Machines as Clients?

Terrell Prude', Jr. microman at cmosnetworks.com
Sat May 8 14:25:24 UTC 2004

Dennis Daniels wrote:

>> There was a comment about the hard disks being useless.  If you have 
>> the thin clients booting from floppies, then that's true.  
>> HOWEVER...floppies have a way of disappearing, so I've cat'ed the 
>> Rom-O-Matic floppy image onto the hard disk, just like you would to a 
>> floppy.  Works great!  Of course, you can't boot the Windows 98 that 
>> was on those computers anymore, but like I care.  :-D
>> --TP
> What about drivers for older monitors... would that work as well? It 
> would be fantabulous to find an easy way to load the all NIC drivers 
> and monitor drivers /sound cards onto the hard-drives of these 
> 'fat-clients'. We've been using NFS installs but a micro-boot 
> installer for K12LTSP that would install the drivers needed for the 
> local hardware onto the local machine...something automatic? :)
> Roughly speaking, I've spent over 100 hours getting 30 nodes running 
> with the help of a linux/hardware enthusiast; 200 man hours spent 
> trying to get random NICs and monitors to work on an entirely donated 
> classroom network.
> When I tell teachers on campus they could do the same thing they say, 
> "No way! I know how much time you've put in there getting it to work." 
> And they're right, with donated equipment getting a network to run is 
> a bear. Unless you're a nut or fanatic most would give up trying to 
> get LTSP up and running on donated machines.
> A plea from a teacher in the treches: make it easier to get older 
> machines, random NICS and ancient monitors into use as clients is a 
> good thing for schools; something that Aunt Tilly the Teacher, and I, 
> can use.   ;)
> best
> dennis

OK, you got it.  Note:  I am emphatically *not* talking about fat 
clients here.  I mean thin clients.  You'll see here in a minute.

1.)  You need a supported NIC, i. e. something for which you can 
download the .lzdsk from www.rom-o-matic.net.  I happen to use 3Com 
3C905's, but RealTek 8129-based cards also work great and are $8 in the USA.

2.)  You need a supported video card.  Any of the old S3 Trio64 boards, 
S3 ViRGE, ATI 3D Rage Pro boards, etc. work very well; I use all three.

3.)  You need enough DRAM.  My experience says that 32MB works very 
well, be it an x86 or PowerMac thin client.  16MB aren't enough.

4.)  You need a supported CPU.  On the x86 side, anything from an 
80486-33 and up works.  Using a Pentium is like using a Ferrari to go 
the local grocery store (you don't need that kind of power, but you've 
got braggin' rights, bay-bee!).

5.)  If you want sound, you'll need a supported sound card.  I find that 
the old SoundBlaster 16 cards work great (we have a lot of those).

6.)  If you want to boot your thin client from the hard disk, you'll of 
course need a hard disk.  For this purpose, a 10MB hard disk is already 
much more than you need (yes, I said 10MB), so one of those old 540MB or 
850MB hard disks will certainly work.

OK, now we have our box that we want to make into a thin client.  You'll 
want a blank floppy.  With this floppy, we're going to make a standard 
EtherBoot "boot floppy."  Since my thin clients happen to use 3Com 3C905 
cards of various vintages (the original, the B, and the C), I issue this 

  [microman at localhost ltsp]$ su root
  [root at localhost ltsp]# cat eb-5.0.11-3c905c-tpo.lzdsk > /dev/fd0
  [root at localhost ltsp]#

Yes, the EtherBoot image for the 3C905C also works on the 3C905B and the 
original 3C905.  :-)

OK, now we have a boot floppy.  Why'd we do this?  We need to make sure 
our thin client's going to work, so why not try it the "standard" way, 
first, i. e. booting it with a boot floppy?  :-)  If things don't work, 
then there's a problem that needs to be troubleshot with the standard 
techniques (is the K12LTSP server actually running, is everything 
plugged in and seated right, etc.).  Once you've gotten your thin client 
to successfully boot to K12LTSP from that boot floppy, then we're ready 
for the next step.  This same EtherBoot floppy can, of course, be used 
for any other thin client with the same type of NIC.

Now we've verified that our thin client actually works.  This is Good.  
So, how do we get the thing to boot from the hard disk?  We do it the 
same way we get the thing to boot from our Rom-O-Matic floppy.  You know 
how we get the EtherBoot image onto the floppy?  Well, we do exactly the 
same thing to a hard disk.  To do that, we need a command prompt on the 
thin client itself.  Just reboot the thin client with something like 
Knoppix in command-prompt-only mode, so now you have a bash prompt.  If 
you don't have Knoppix, or if it takes too long for you to download 
Knoppix, then you can use Damn Small Linux, available at 
http://www.damnsmalllinux.org; it's only 55MB.  If you don't have a 
CD-ROM drive in your thin client, not to worry.  Use tomsrtbt, which is 
a floppy-based distro that runs in "8 meg to boot, more to unpack", so 
it'll fit fine in 32MB.  Tomsrtbt is available at http://www.toms.net/rb/.

OK, now we have our bash prompt on our thin client.  So far, so good.  
Now we have to actually get the Rom-O-Matic boot image onto the hard 
disk.  How?  Easy.  On that thin client, pop in that EtherBoot floppy 
and type this:

  [root at knoppixbox root]# cat /dev/fd0 > /dev/hda

and sit back and watch the entire contents of that floppy disk get 
copied, bit for bit, onto the hard disk, starting with sector 0,0,1.  
Essentially, you've made your hard disk into an "EtherBoot hard disk."  
It acts just like a really big (and, of course, much faster) EtherBoot 
floppy!  This does have the side effect of wiping the MBR and partition 
table that was originally on the hard disk, so you're not going to be 
booting that Windows installation anymore, be it on NTFS, FAT, HPFS, or 
whatever.  But, again, like we care, since we want to get away from 
Windows anyway.  :-) 

BTW, the other way to do this is by taking a second FAT-formatted 
floppy, copying the .lzdsk file onto this second floppy (not 
cat'ing--copying, as in the "cp" command or the GUI equivalent), popping 
that floppy into your thin client, mounting that floppy, and doing this:

  [root at knoppixbox root]# cat /mnt/floppy/eb-5.0.11-3c905c-tpo.lzdsk > 

Once that copying's done, reboot your thin client, and it'll come up 
with a K12LTSP prompt faster than you've ever seen it before.

Now, there was a question about "drivers" for monitors.  Monitors don't 
use device drivers; video boards do.  Thus, there is no "driver" for a 
monitor any more than there is for a keyboard.  Note that X11 will 
automagically detect your thin client's video board when you fire it up, 
so you don't have to be concerned with the video driver...provided, of 
course, that it's supported by XFree86.  :-)  Most are, so this 
shouldn't be an issue.

There are two concerns to have with "ancient" monitors:

1.)  Can the monitor run at a resolution that will make the K12LTSP 
desktop enjoyable to use?
2.)  Is the dot pitch sufficiently small enough that it won't kill the 
users' eyeballs?  I remember those 0.39 dot-pitch screens all too well, 
and I would never put a child in front of such a screen.

What you want to do is make sure that you're running at a resolution of 
at least 800x600x16 on your thin clients.  I don't know a video board 
made since 1996 that would have trouble with that.  My thin clients run 
at 1024x768x24, and this is with 17" CRT monitors.  Decent 15" monitors 
will work at 800x600, but....  My advice would be, if you don't have 
monitors that are capable of 1024x768, are 17", and have a 0.27 dot 
pitch or less, that you go ahead and pick some up.  They can be had for 
$50 apiece, and you will be helping to preserve the health of eyeballs 
by doing so.  We all have tight budgets, but please don't visit 0.39 dot 
pitch on your kids.  Really.

Now that things are up and running, sit back and enjoy.  For those 
critics that told you "no way" because you spent all those hours with 
donated "random" hardware, well, you'd have to do that anyway if you 
were running Windows on them, too.  That's an issue with random 
hardware, not so much the operating system that you're running on it 
(GNU/Linux supports *lots* of hardware).  Furthermore, you can take 
satisfaction in the fact that all those hours that you spent, you won't 
have to do that again when the next Windows virus/worm comes out.  You 
now have only one box to maintain--the K12LTSP server--instead of 30.  
My K12LTSP lab was entirely unaffected by Sasser, for example, so it is 
time well spent doing this.  The biggest issue, I've found, is the NIC.  
Keep those consistent if at all possible.  Again, I've seen cards based 
on the RealTek 8129 chip for $8 in stores, and they are definitely 


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