A few questions

[Kerry Hoath]

If Linux is the only os on the drive; you don't
need disk manager or any of that large disk cludging software.
The bios on the 486 can probably access the first 504 megabytes
of the drive, that is up to cylinder 1023 head 16 sector 63.
Newer bioses shift bits from the cylinder to the head field so you can
see IDE geometries of 524/64/63 for the hypothetical 540m drive above.
The problem is that the IDE _hardware_ is limited to 4 bits for head, i.e. 16 heads
and the bios if it isn't LBA or extended int13 capable is limited to 1024 cylinders.
They use CL for cylinder and the top 2 bits of the DH register so that gives 6 bits for cylinder.
Compine these 2 limitations and you can't read past 504 megabytes on an old bios.
Linux however only uses the bios for booting i.e. lilo so there are 2 simple 
solutions.
1: Use a boot floppy. Stick the kernel on the boot floppy optionally with lilo
or syslinux and partition the drive as you please. You'll see the full 3gb
under Linux.
2: Make sure the /boot partitions for however many distributions are on the drive
are below cylinder 1024. Put the rest of Linux
wherever you like on the drive. You could for example have 2
primary partitions for /boot say 50 megs each. Now create
2 logical drives in the extended partiton of 1.4gb each. You can install _2_
distributions of Linux and pick which one you want at boot with lilo.
This could let you have the screw around copy and the production copy.

Golden rule: If your bios predates LBA, all of /boot or / if you
preferr must be below cylinder 1024.

If any of this is hard to understand feel free to ask for clarification.

Regards, Kerry.
On Wed, Jul 11, 2001 at 08:40:27PM -0500, John Gunn wrote:
> Hello All:
> 
> Well still haven't install or even downloaded 8.0 of the slackware
> distribution of Linux but I have a few questions.  I finally found a box I
> can experiment with and is a 486 Compact with 16 megs of ram.
> 
> I am going to use an old which is about 6 years western digital 3.1 gig and
> am wondering using western's utility to kind of pre-format the disk so that
> cmos can read the full 3.1 gig drive should I expect any difficulty with
> this utility getting in the way of the Slackware  and Speakup installation
> of Linux?
> 
> Also can 1 use other distributions such as Red Hat Mandrake etc?
> 
> Any help would be appreciated and if some of this is a little off topic,
> sorry.  smile
> 
> 
> 
> 
> _______________________________________________
> Speakup mailing list
> Speakup at braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup

-- 
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Kerry Hoath: kerry at gotss.net
alternatives: kerry at gotss.eu.org or kerry at gotss.spice.net.au
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