hargle
Veteran Member
So I had a free moment at work today, so I thought I'd do something fun, which is disassemble the ADP50 controller's BIOS.
There's some interest here in getting an updated BIOS available to break the 528MB barrier, and I'm sure it's possible to do.
So, I'm looking at the IDE reader/writer code, and unless I'm missing something, it all appears to be memory mapped I/O! I've never seen anything like it before - certainly not to a hard drive.
Looking at the specs:
http://stason.org/TULARC/pc/hard-di...LLEY-COMPUTER-INC-Two-IDE-AT-Interface-d.html
Sure enough, there's no jumpers or dip switches for an IO base address.
There's also no settings for the BIOS base address either, so that's a little odd too...
I find this really curious, and made me wonder why this sort of thing wasn't more common. Is it faster? Is it cheaper to build a card this way?
There's some interest here in getting an updated BIOS available to break the 528MB barrier, and I'm sure it's possible to do.
So, I'm looking at the IDE reader/writer code, and unless I'm missing something, it all appears to be memory mapped I/O! I've never seen anything like it before - certainly not to a hard drive.
Looking at the specs:
http://stason.org/TULARC/pc/hard-di...LLEY-COMPUTER-INC-Two-IDE-AT-Interface-d.html
Sure enough, there's no jumpers or dip switches for an IO base address.
There's also no settings for the BIOS base address either, so that's a little odd too...
I find this really curious, and made me wonder why this sort of thing wasn't more common. Is it faster? Is it cheaper to build a card this way?