[techtalk] Running Linux from a zip disk.

[Conor Daly]

On Mon, Mar 26, 2001 at 08:14:32AM -0800 or so it is rumoured hereabouts, 
Maria G Martinez thought:
> According to what I have read, the Debian Superrescue
> CD has native PPA (apparently the name for the zip
> driver??) support for the zip disk (or something like
> that).  I have booted my puter at home with tomsrtbt
> before...  I have never run an OS from a CD.
> Now that you put things in perspective to me, it
> sounds horribly complicated.  Especially since I don't
> have a zip drive at home (but all the computers at
> school do).

It's not that horrible really.  It is a *bit* complex but that's just what
computers are good at, handling complex tasks repeatedly.  There are
basically 2 things required for such a Floppy/zip/CD system;

1. Letting the floppy know where to find the zip and CDROM disks.  If the
setup is to run on the same machine all the time, this info can be 
hard-coded but if different machines may be used then some means of
detecting which drive is which is required (no great problem that, I've
got an init script somewhere that does just that).

2. Mounting the zip disk and getting the remainder of the boot process to
run from there.  Again, that's straightforward enough; the various
installation CDs of the Linux distros tend to load a second stage from CD
once the initial boot has happened.
 
> I am attaching a list of the hardware (which I hope is
> readable) of the computer here (just in case it might
> be useful, and there are any takers).  This is one of
> the labs with slightly different computers.

The main thing you need to know about the hardware (for *this* task at
least) is the type of zip disk (internal / external) and where it's
connected if internal (Primary / secondary IDE and Master / slave).  

 
> I also have the feeling that this horrible complicated
> experiment will make me learn something, which is what
> I ultimately need.  To learn.

Ok, let's dispense with this "horrible" word shall we? :-)

What is available from a project like this is an understanding of the
interdependent nature of the system and how bootstrapping itself works.
The computer starts off with a tiny built in program (the BIOS) and uses
this to load and run a more complex program which, in turn, loads an even
more complicated program that runs the OS.  In this case, we start off
with a (relatively) simple program on the floppy.  This mounts the zip
disk thereby adding a layer of complexity and capability and the zip disk,
in turn, mounts the CDROM and loads the main OS.
 
> I'll post again later, I am already late for class!!!

Quick! Run!
 
> Maria
 
Conor

-- 
Conor Daly <conor.daly at oceanfree.net>

Domestic Sysadmin :-)
---------------------
Faenor.cod.ie
  1:46pm  up 27 days, 23:20,  0 users,  load average: 0.00, 0.00, 0.00

Hobbiton.cod.ie
 12:56pm  up 27 days, 22:06,  1 user,  load average: 0.00, 0.00, 0.00