I don't see anything in Ralf Brown's classic list.
There's always the IDE port itself. Have fun.
formatting link
If you have PnP, read up on all of that too. You'll probably need to enter protected mode to access most of the address space, and that may be where the advanced features lay. AFAIK, IO space isn't affected by RM/PM, but most PCI+ devices are memory mapped so you're kind of screwed otherwise.
And from there, obviously, you need to know where the registers and spaces are, and how to use them. In other words, writing vendor-specific drivers. Good luck. You may be better off finding the respective Windows driver and reverse-engineering it, or building an interface to run it as such. Or finding the respective Linux driver, and implement the interface (freely published) and adapt it to DOS interfaces.
Incidentally, you didn't note what kinds of disks you're trying to access. You also didn't specify what age of computers. IBM/Lenovo, HP and Dell are all current brands, and their latest products run modern OSs that access "large" disks just fine, so your problem seems to have a trivial solution... :-)
Tim
--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Design
Website: https://www.seventransistorlabs.com/
"Hul Tytus" wrote in message
news:qkp872$hhp$1@reader2.panix.com...
> I'm looking for the method(s) used to access disks with greater than 8
> gigabytes capacity
> on the IBM style computers, ie Compaq/hp, Dell, etc? I've checked interupt
> 13h for the
> presence of "extended" capabilities but have found nothing on 4 different
> machines.
> There is, obviously, another access path. Anyone know what or where it is.
>
> Hul
>