OSDev.org

I can't promise that these will be useful, but I hope so. I have not looked at all of them in detail yet.

http://www.cs.sun.ac.za/courses/pregrad ... loppy.html

http://www.cyberscriptorium.com/osjourn ... ile&file=9

http://users.win.be/W0005997/GI/floppy.html

http://www.nondot.org/sabre/os/files/Disk/FLOPPY.TXT

http://members.tripod.com/~ladsoft/dos/floppy.txt

http://thor.prohosting.com/~walles/source.htm

http://www.hynix.com/eng/products/syste ... p07_05.jsp

http://bloggins02.dyndns.org/

http://www.xs4all.nl/~matrix/fdd_pt.html

http://members.tripod.com/~oldboard/assembly/765.html

http://jtmos.sourceforge.net/jtmos/boch ... y/floppy.c

ftp://void-core.2y.net/pub/docs/fdc/820 ... asheet.pdf

ftp://download.intel.com/design/periphr ... 047403.PDF

http://mudlist.eorbit.net/~adam/pickey/ports.html

I've also found a large number of pages on DMA:
http://www.infran.ru/TechInfo/BSD/handbook258.html

http://www.bitzenbytes.com/101/DMA.htm

cires.colorado.edu/~jjose/DMAFundamentals.pdf

http://p6boss.ifac.cnr.it/locdoc/hardware/dma_prog.pdf

http://www.inf.pucrs.br/~moraes/arquitetura/dma.html

Some assembly-language OSes that already have disk support:

http://www.ludd.luth.se/~ivileel/

http://www.v2os.cx/

Finally, odd though it may sound, it occured to me that the Bochs source for the disk emulator may be of some help:

http://bochs.sourceforge.net/cgi-bin/lx ... y.cc?v=1.3


I could also point out that Messmer's _Indispensable PC Hardware Book_ has a detailed section on direct access to the FDC. I'd seriously recommend that anyone who want to do systems-level programming read the entire volume cover to cover first, and always have a copy of the latest edition on hand at all times. It really does live up to it's name.

http://www.awprofessional.com/catalog/p ... 4CD4DBDFD0}

If you are willing to buy from them, Amazon has a special deal on this together with _The Undocumented PC_ by Gilluwe that looks like a decent bargain...

http://www.amazon.com/exec/obidos/ASIN/ ... 87-7852047


Whew! I hope that something in all of that helps. I'll have to go through some of those still, myself.