Bios disk read error help

[abstractmath]

Actually, scratch my last post. It seems to be working now? I think I forgot to rebuild my project or something.

[abstractmath]

Oh that's funny. I still can't read past 40 blocks, even with the BIOS extension.

[Octocontrabass]

Does your disk have 40 blocks?

[abstractmath]

I'm not entirely sure. How can I check?

[Octocontrabass]

How big is one block?

How big is your disk?

How many blocks can fit in your disk?

[abstractmath]

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???

[Octocontrabass]

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.

[abstractmath]

Is there a way that I can specify a drive size in qemu? I think that might help a bit.

[Octocontrabass]

Of course.

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

[abstractmath]

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.