28 Nov
2008
28 Nov
'08
1:59 a.m.
On Thu, 27 Nov 2008, Tony Duell wrote:
OK, but IDE bus interface cards do exist. Meaning
cards that link ISA
(or whatever) bus to an IDE drive. For ISA, it's little more than an
address decoder and buffers (I happen to be using one in this PC).
Right, that's what I've called an IDE HBA (host-bus-adapter).
Sure you can. Make a PCB containing a WD1003-like disk
controller. On one
side, have ST412 connectors to conencto to that sort of drive. On the
Ehm, that *is* a WD1003, because the so-called IDE interface really is a
simplified ISA interface for the AT-Bus. That is why it is (more
correctly) called AT-A (or ATA) = AT-Attachment. AT here means IBM AT Bus.
other, have an IDE interface -- data lines, 3 address
lines, etc. In
other words the original PC/AT disk controller board minus the floppy
controller and minus most of the address decoder. Linked to the IDE bus
Right.
interface I mentioned just now, you have a complete
ST412 hard disk
controller system. And the seond part of it could reasonably be called an
IDE (host interface) to ST412 (drive interface) bridge board.
Well I prefer to deny the existence of a dedicated IDE bus, but IDE
interface is OK since the extinction of the AT-Bus.
And since we're at it, I'd like to point out that SCSI drives are IDE
drives, too, but noone calls them so ;-)
Oh, what a world, you buy ATA drives (or even SATA) but don't have an AT
bus any more. Instead you have IDE interfaces on the PCI bus (mostly
integrated into the MB chipset). But SATA is more like SCSI when compared
with SAS...
Christian