baby steps #9
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smaffy
come on! start writing some PMode =P [ant]
(ant = almost no text)
..it is possible to do that with the bios =P
..it is possible to do that with the bios =P
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smaffy
Re:baby steps #9 - dma floppy
well..
it is possible to access the floppydisk from bios (int 0x13).. that was what i meant.
it is possible to access the floppydisk from bios (int 0x13).. that was what i meant.
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Tim
Re:baby steps #9 - dma floppy
Your goal of doing cool stuff is admirable. But what can we learn from accessing the floppy drive directly from within the boot sector?
a) that it's easier and shorter to use int 13h
b) how to do ISA DMA and port I/O in less than 512 bytes
(a) isn't much use once you start writing a protected mode OS proper, although it is if you're doing your own boot loader. (b) isn't much use even outside of a boot sector, since ISA DMA is only really used in three specific areas: floppy drive controller, ISA sound cards, and the enhanced parallel port.
One may learn something from this which could be applied to a real OS floppy driver. But then, if you were doing this for 'real' (i.e. not in a 512-byte boot sector), you'd put a lot more effort into designing it and less into making it as small as possible.
a) that it's easier and shorter to use int 13h
b) how to do ISA DMA and port I/O in less than 512 bytes
(a) isn't much use once you start writing a protected mode OS proper, although it is if you're doing your own boot loader. (b) isn't much use even outside of a boot sector, since ISA DMA is only really used in three specific areas: floppy drive controller, ISA sound cards, and the enhanced parallel port.
One may learn something from this which could be applied to a real OS floppy driver. But then, if you were doing this for 'real' (i.e. not in a 512-byte boot sector), you'd put a lot more effort into designing it and less into making it as small as possible.
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Tim
Re:baby steps #9 - dma floppy
Btw: you're certainly not doing anyone any harm, but I think you could be spending your time writing tutorials (articles?) on something more useful (especially considering the 'baby steps' subject line).
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crazybuddha
Re:baby steps #9 oops
Thanks for setting me straight. I'll go spend my time doing something more useful.
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DynatOS
Re:baby steps #9 - dma floppy
Easier and shorter is usually for C, but in this case, he is trying to get down and dirty as possible into various fields of x86 programming, all are valid, all are useful, and all are interesting to study to see where PC's have evolved from. Tim, I've seen your posts on this board, and I have to say, your opinions on a subject are needed but only once... try not to ruin other people's projects because they don't suit you "logically".Tim Robinson wrote: Your goal of doing cool stuff is admirable. But what can we learn from accessing the floppy drive directly from within the boot sector?
a) that it's easier and shorter to use int 13h
b) how to do ISA DMA and port I/O in less than 512 bytes
PS: It is your identical mentality that allows M$ developers to design libraries twice as large as the previous version just to keep my window rectangular
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Tim
Re:baby steps #9
Hey, I'm not trying to tell people what to do, and I wouldn't expect anyone to listen to me if I did. All I've done on this thread is questioned what crazybuddha is aiming for; if I'm repeating myself then it's because I still don't understand his overall strategy. If, for any piece of information posted, someone learns from it, then it's useful.