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Index > OS Construction > You modify the # of sectors and get 3MB instead of 1.44MB?

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Joined: 30 Jul 2013
Posts: 339
Location: Asia, Singapore
sid123 14 Nov 2013, 09:40
I just wanted to ask a stupid question,
While searching through a mail list I found this :

Well, recently I've been trying to boot MikeOS off of a hard drive. The only way, so far, that has worked is as follows:

- take bootload.asm and modify it to acknowledge whatever size HD I'm using (I used a 3 MB blank virtual hard drive, fixed size)
- copy a 1.44 MB MikeOS floppy image overtop of the HD image.
- compile bootload.asm.
- implant the new bootsector onto the HD image.
- boot 'er up!

I used my CHKDSK command (the original, developer's VOL) to check the new number of sectors. It worked.

Expect further posts.

Troy Martin

Really? You modify the number of sectors, and it's it. You get 3MB instead of 1.44MB(?)
Although this WON'T work on emulators and real floppies, would it work on USB's? (After you burn the image on that)

"Those who can make you believe in absurdities can make you commit atrocities" -- Voltaire https://github.com/Benderx2/R3X
Post 14 Nov 2013, 09:40
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When all else fails, read the source

Joined: 24 Aug 2004
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Location: In your JS exploiting you and your system
revolution 14 Nov 2013, 10:11
Moving to OS Construction. If it stays in Test Area then it will get deleted.
Post 14 Nov 2013, 10:11
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Joined: 25 Aug 2004
Posts: 618
cod3b453 15 Nov 2013, 17:29
Booting always happens on the first sector of a disk and floppy, hard disk and USB all have 512 byte sectors. Hence, as long as the CHS* parameters are also used and correctly set up, it will work fine. This can also work on CDs with BIOSs that support emulation mode.

*Note that the size is not the real issue but having the correct arithmetic for consecutive sectors
Post 15 Nov 2013, 17:29
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