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 Post subject: Re: Bios disk read error help
PostPosted: Tue Oct 13, 2020 12:16 pm 
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Actually, scratch my last post. It seems to be working now? I think I forgot to rebuild my project or something.


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 Post subject: Re: Bios disk read error help
PostPosted: Tue Oct 13, 2020 12:22 pm 
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Oh that's funny. I still can't read past 40 blocks, even with the BIOS extension.


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 Post subject: Re: Bios disk read error help
PostPosted: Tue Oct 13, 2020 12:23 pm 
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Does your disk have 40 blocks?


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 Post subject: Re: Bios disk read error help
PostPosted: Tue Oct 13, 2020 12:26 pm 
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I'm not entirely sure. How can I check?


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 Post subject: Re: Bios disk read error help
PostPosted: Tue Oct 13, 2020 12:28 pm 
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How big is one block?

How big is your disk?

How many blocks can fit in your disk?


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 Post subject: Re: Bios disk read error help
PostPosted: Tue Oct 13, 2020 12:35 pm 
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I. Do. Not. Know. I'm looking at int 13h on wikipedia and I do not know how to get that information. Do I use AH = 0x48 or is there something better suited to what I need to know???


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 Post subject: Re: Bios disk read error help
PostPosted: Tue Oct 13, 2020 12:40 pm 
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If you're reading a hard disk with INT 0x13, the block size is 512 bytes. The specifications allow for different block sizes, but in practice no BIOS supports it.


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 Post subject: Re: Bios disk read error help
PostPosted: Tue Oct 13, 2020 12:45 pm 
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Is there a way that I can specify a drive size in qemu? I think that might help a bit.


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 Post subject: Re: Bios disk read error help
PostPosted: Tue Oct 13, 2020 12:46 pm 
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Of course.

The drive size is determined by the size of the disk image you're using.


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 Post subject: Re: Bios disk read error help
PostPosted: Tue Oct 13, 2020 12:51 pm 
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Ohhhhh okay, now it's making sense. My entire image file is about 21K in size, and that would make sense that the drive size wouldn't be past 40 blocks since 40 * 512 = ~21K.


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