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First post, by agent_js03

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Rank Newbie
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Newbie

Hi,

I am trying to get DosBox working with a boot image. I am following this guide: Sample usage of a harddisc image in DOSBOX
I am creating a disk that is 1GB (1024 MB) in size.

Here is the output for my bximage:

I will create a 'flat' hard disk image with cyl=2080 heads=16 sectors per track=63 total sectors=2096640 total size=10 […]
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I will create a 'flat' hard disk image with
cyl=2080
heads=16
sectors per track=63
total sectors=2096640
total size=1023.75 megabytes
...
The following line should appear in your bochsrc:
ata0-master: type=disk, path="c.img", mode=flat, cylinders=2080, heads=16, spt=63

Then I go in dosbox and mount the image with the following command:

imgmount 2 c.img -size 512,63,16,2080

And then I boot into DOS 6.22 and do an fdisk, and then a format. This is what the format prints out:

16,453,632 bytes total disk space

If I go to C: and do a "dir" command, it says:

16,244,736 bytes free

I am baffled. I created a 1GB image, why is it only showing as 16MB? Can someone help me understand what I'm doing wrong? The sizing should be right, the bximage output showed 16 heads, 63 sctors per track, 2080 cylinders, and also 2096640 total sectors so the 512MB sector size should be right since 512MB x 2096640 is 1,073,479,680 bytes (1 GB). Any help?

Thanks!

Reply 2 of 3, by Jorpho

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Rank l33t++
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l33t++

Does using "-fs none" make a difference?

You might also have better luck with imgmake, which should be included in the SVN version. See for instance Windows 9x DOSBox Guide (Not officially supported) .

Reply 3 of 3, by ripsaw8080

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Rank DOSBox Author
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DOSBox Author

FDISK has a limit of 1024 cylinders, which is actually the BIOS INT 13h limit, and you're seeing how it messes up when that limit is exceeded.

The solution is to use more heads and keep the cylinder count under 1024, e.g. -size 512,63,32,1023

BTW, using "-fs none" is pretty much required with a blank image because DOSBox would refuse to mount it otherwise.