Floppy driver without DMA

Lon · Post by **Lon** » Wed Oct 25, 2006 10:27 am

I was just wondering if there are any tutorials out there or code examples of programming the fdc without using DMA or is it just the same apart from setting the ND bit to 1 when you run the specify command?

TIA,
Lon

Dex · Post by **Dex** » Wed Oct 25, 2006 10:51 am

Word of warning, i when i first started coding my floppy driver, thought it would be much easier to start with, to make a floppy drive with out DMA.
I then spent alot of time with the code not working and trying to fix problem, there were no example of working code, i maybe wrong, but it maybe a case of the vesa3 pmode interface that is well doc, but no one has got it working.
So i would say use DMA.
But if any one has working code for any of my above example please show so i can rethink this myth.

Lon · Post by **Lon** » Wed Oct 25, 2006 11:50 am

Thanks for the info. I'll save myself a whole load of time and just use DMA although if anyone does have any info on doing it the non-DMA way I would still be very interested to know.

Thxs,
Lon

deathangel · Post by **deathangel** » Wed Oct 25, 2006 2:11 pm

Non-DMA is generally much slower as you have to use port I/O for each byte you read from the floppy disk. You basically set it up exactly the same but without the DMA enabled, then you wait for an interrupt and either read/write throught the DATA port the bytes.