Re: read floppy problem

> When i want to use int 0x13 to read 65 sectors a time, it give me
> error 9 data boundary error (attempted DMA across 64K boundary or >80h
> sectors).
Yes, the DMA doesn not use segments like the CPU. It can only handle a 64K
address space. Therefor the 1MB or 16MB address space of the PC-XT/AT is
split up into 64KB (128KB for 16-bit transfer) blocks, which do NOT overlap,
like on a CPU. A DMA transfer cannot cross that boundary.
Either split up your reads or use a different address for your buffer.


H


.

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