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Floppy reading with sectors, heads and tracks

Posted: Thu Jun 19, 2003 11:11 am
by Thunder
Hello,
I'm confused,first my bootloader read kernel just adding sectors (track has 18 sectors), so I wrote that int 13h must read say 24 kb, it loaded, but after i added code it saw to be not working.

Then I found info that we can read first:
17 sectors (first is bootloader), head 0, track 0, then
18 sectors, head 1, track 0,
18 sectors, head 0, track 1,
18 sectors, head 1, track 1,
and so on...

But it seems that this don't work,
How I need to change tracks and heads to read kernel correctly?

Btw, where LInux and Windows kernels are starting at RAM, what paging they use (4kb or 4bm or mixed) and what multitasking they use (hardware or software)?

Thanks :)

Re:Floppy reading with sectors, heads and tracks

Posted: Thu Jun 19, 2003 11:52 am
by Pype.Clicker
the list of sectors you gave should work fine (though i would rather have started the kernel at head1, track0, sector1 rather than head0, track 0, sector 2 for simpler code -- keeping the rest of first track for stuff like directory (if any), configuration files,etc.

Re:Floppy reading with sectors, heads and tracks

Posted: Thu Jun 19, 2003 12:23 pm
by Unexpected
Thunder's second question isn't in subject..
But can anyone answer?
Where Linux and Windows kernels are starting at RAM, what paging they use (4kb or 4mb or mixed) and what multitasking they use (hardware or software)?

Re:Floppy reading with sectors, heads and tracks

Posted: Fri Jun 20, 2003 2:13 pm
by TB
Hi,
19th sector of the floppy drive has the following params:
- head 1
- track 0
- sector 1

So bassicaly, what you do is:
1. read your 17 sectors (0/0/2 - head/track/sector accordinly)
2. switch head to 1
3. read 18 sectors

Afterwards you'll have to increase "track" and set head to 0, in order to read 37th sector.

Kind Regards,
TB.